Escape Room Object Placement Puzzle using Arduino/RFID

[@PanayiotisMavrokefalos]

I kinda saw all your videos! The way of explaining things is so simple and to the point easily perceived by literally 0 experienced viewers.

[@RUSSCAV]

Best Escape Room Audruino tutorial I've ever watched, and I've watched them all. Thank you for breaking it down. This is what I needed.

[@lennylein]

Hello Alistair, it's a nice and straightforward tutorial, just wanted to share a bit of additional information: 1) You can (in theory) run this setup with a much larger number of RFID reader modules. What limits your setup is the amount of power the Arduino can provide. If you power the readers with an external power supply you can go way beyond 4. 2) Using longer connector cables is like adding an additional resistor in front of your pins. I found that as long as you don't exceed around 1m of length the setup still works fine 3) One minor nitpick about your code: It's not necessary to call PCD_Init() on your readers in each loop. You can simply init each reader once inside the setup() routine. Cheers and keep up creating these great tutorials!

[@PlayfulTechnology]

Hi Andy, the problem with adding more readers is not the power requirements (though you obviously need to address that too) - it's the additional capacitance you're creating on the SPI bus. Assuming you're running the SPI clock line at 4MHz, then once you've added any more than about 4 readers you'll find that the return signal on the MISO line is neither clean nor quick enough to be received within a single clock cycle (you can see this easily using a scope).

[@AA-kc5mu]

Thank you for this explanation! Using this setup, how would you power the Arduino without connecting to the computer?

[@PlayfulTechnology]

You can supply 7-12V on the VIn pin, or via the DC Barrel Jack (both of which get stepped down to 5V via the linear regulator on the Arduino board)

[@toffl766]

This is exactly what I need for a different project and you explained it perfectly! Thanks!

[@larrythehypnotist]

Hi, thanks for sharing this. How do you write to the cards using this set up?

[@jamminsammy1928]

Every now and then , one or more rfid readers don't read the specific tag. That means that the puzzle can't be solved and the mag lock stays activated. I tried to use an external button that is connected to the reset pin on my nano , to open the mag lock remotely but it only resets the arduino while the lock stays activated. Is there a way to push the "reset" button to release the mag lock just in case the puzzle fails , without having to add code? Or what about adding a "softreset" libray?

[@pokegarchomp]

Is there a more elegant solution these days, particularly for puzzles that need more than 4 inputs? I can definitely just wire up two different arduinos if that's the best approach, but I wonder if there's something better

[@iainprendergast8311]

Thanks

[@adelinakondratjeva5503]

can we use transistor instead?

[@josephvanclersson7906]

Hey is there any step by step to do the same please!?

[@Y0ujetdefloor]

Hi Alistair. Cant quite work out which options I need to select in Patreon to get this info. Would appreciate your advice. Also how long am I locked in for ( as currently I just want this code & layout) Help!

[@jetdefloor47]

@Scenic Rim Carpet Cleaning Yes and no. I didn't get a reply from Playful Tech. I ended up creating my own code and circuitry to build a "put 9 reindeer into order" for a XMAS escape room based on a single Arduino Nano V3.

[@jetdefloor47]

​@@yasirisktas3239 See the previous reply. I ended up creating my own code and circuitry based on a single Arduino Nano V3. It will handle upto 10 RFID sensors and can trigger a relay which can control a mag lock

[@istvanagoston7137]

@Playful Technology Thank you for the content, have you maybe come across an issue where the RC522's can communicate well by themselves, but when two is using the MISO pin, it all breaks and it is unable to read anything? Pulling out one of the MISO cables enables the other RC522 to read.

[@istvanagoston7137]

Resolved, seems like the "pricier" RC522 (4 dollars) was the issue, I switched them to cheap ones, and it is working properly now :D

[@djom20]

Hi Thanks for this amazing video, and a dude, How did you included the rfid component into Fritzing?

[@btroodenburg]

Where did you buy the relay and the thing that gives power?

[@josephroberts991]

What adapters are being used to connect the RFID readers into the board? It appears they are using CAT5 or similar cables, but then they are in an adapter and single wires the rest of the way up to the reader.

[@maxmatthes7417]

Can you also give me the link to the RJ45 connectors that you‘ve used? Maybe also how you wired them? Thank you very much and by the way, great tutorial! 👌

[@daniellewis1511]

How close could you have each antenna to each other? I am wanting to create a larger read area to read smaller tags, so want to get the antennas as close to each other as possible to read as many tags in that one space (rather than picking up what is closest to specific antennas)

[@daniellewis1511]

Effectively, can I use interference to my advantage 😂 or does that interference actually affect the other antennas around it as well as the multitude of tags we are trying to read

[@martincornu1487]

Thanks for this amazing tutorial! Very helpful. I am wondering which connectors do you use to connect all rfid readers common wires (like MOSI, MISO or RESET)? It saves a lot of arduino inputs/ouputs.

[@jasonrackbrain7706]

Hi Alistair, I have joined your patreon and downloaded the code and instructions on how to build this escape room puzzle, and I am currently designing an in-home escape room for some friends to try out at Halloween (thought i'd start early!), and decided that this particular puzzle will work ideal for my "end puzzle" which when solved will win the game. It just so happens that having four RFID sensors is perfect as there will be 4 items with an RFID tag attached, and four plastic "pillars" with a concealed RFID sensor in the top of each, where the items must be placed in a certain order to win the game. But winning the game will trigger some 12v green led strip lights instead of a maglock, so all good there. But I was wondering if it was possible to add an extra level of complexity to this puzzle, as I want to also incorporate some neopixel rings (as featured in your mastermind puzzle game), in fact there will be 4x neopixel rings, one inside each pillar, as well as a RFID sensor. So essentially what will happen is when the four items are placed in the correct order, the arduino will trigger the relay which will turn on the green led strip, but also the arduino will separately trigger the neopixel rings to flash green inside each pillar. My first question is if there are 4x neopixel rings, do I need a separate capacitor and resister for each, or can they just all share the one capacitor/resistor since they will all be in parallel and all be triggered at the same time? My second question is that I also want to have a condition where if there are NO tags on ANY sensors, then all lights are off, including the 4x neopixels. But if there is at least ONE tag or more on a sensor (correct or not) it will trigger the neopixels only to flash RED, as if to 'indicate' that a tag has been detected at a sensor but the puzzle is not yet complete. So basically the flowchart would be something like this: condition A: NO tags on ANY sensors = ALL LIGHTS OFF (ie reset) condition B: one or more tags on any sensors (but puzzle not solved) = all neopixel rings flash red condition C: all tags on correct sensors (puzzle solved!) = neopixels all flash green and led strip light is triggered by relay. I was originally wanting to have it so only the neopixel for the respective sensor would light up when a tag is detected, but I thought this would be too complex, so having all four neopixels light up together, even if only one sensor is triggered, would probably make the code much simpler. Regards, Jason

[@OhYa1337]

does he respond better to patrons? I really need to get this but need to know if it does make sure that all are in place before it activates? Meaning, if I place 1, remove it, then place another & so on, will it still work? I am trying to make a puzzle that requires 5 objects to all be in place before it will open

[@arteagapadillanallely7284]

Hi, I bought the pn5180 boards, and a I2C IIC LOGIC LEVEL CONVERTER BIDIRECTIONAL MODULE FROM 3.3V TO 5V, I want to test the board, can you share the connections and the code that we can use?

[@itolond]

what app are you using there?

[@vanessavalenzuela8415]

Hi sir, have you tried to use multiple rfid reader in one nodemcu esp866? Thankyou

[@music4note]

But how do you then get the puzzle to be further away from the arduino? Or do you have to get a smaler ardiono for each riddle? Can you even do multiple puzzles on 1 arduino?

[@osseo9947]

What is the max distance between the RFID reader and the Arduino?

[@noellezahui4297]

please the code

[@rockistillson]

do you have any examples of using arduino puzzles in an outside setting. i am looking for puzzles that need little reset that can remain outside year round.

[@lasbikeride7171]

so you can use two RFID reader in one arduino,so it is possible to use 2 reader for login and logout system?

[@jessegazic9467]

Hey, Alistair! I've run into a problem with this sketch and haven't seen anyone in the comments with the same issue. My RC522 readers are reading the tags that ship with them (the white cards and blue fobs), but not the common sticker tags. I know they sometimes come in different 'flavours', but I'm surprised to get no reading from standards like NTAG213/NTAG15 stickers. Is this something you've experienced working on this or other RFID-powered projects?

[@Kokusnussaffen]

Is the Arduino Code for the lock part of the git examples? I would like to use exactly this one for a puzzle.

[@Crackeditnc1]

Excellent! Great tutorial illustrating a concept that can be hard to grasp for newbies. Well done.

[@PlayfulTechnology]

Thanks - that's a really kind comment :)

[@superescaperoom991]

+ Especially for someone who is in electronics full zero. We make escape rooms around the world and people often turn around having problems with electronics.

[@valou3108]

I followed these instructions, but unfortunately, it does seems to work for me... As for the diffetent tutorial I followed, I have always the same problem : "WARNING: Communication failure, is the MFRC522 properly connected?" at the initialization. And then, nothing.. If only one RFID reader is connected, it works but it does not work anymore with many readers. And I don't have a clue of why, as I juste follow the instruction of the video...

[@PlayfulTechnology]

If one reader works, but two or more don't (and you're sure that you've got the wiring correct), that suggests that perhaps your power supply is not capable enough to provide enough current - can you try to use a separate 3.3V power supply? And how long are the wires you're using to connect the SPI pins? Keep them short - less than 1m, preferably closer to 20-30cm to avoid signal loss/lag.

[@sergid98]

Hi! The function dump_byte_array is not declared in the video, right? Cool project!

[@hishamhisyam1691]

bro do you know how to write the function? mine says not declare and im stuck.

[@remconet]

Hi again, I'm getting a: 'dump_byte_array' was not declared in this scope. And I don't know what I'm doing wrong... for now I'm using 2 rfid readers and adapted the code to that. Any advise?

[@PlayfulTechnology]

remconet Make sure you've included the entire code listing - the dump_byte_array function is defined right at the bottom.

[@remconet]

Aw I see. I missed that since I did your tutorial manual with you and it's not in the video. So I guess I can't finish it now.

[@PlayfulTechnology]

You haven't missed anything - the link to download the code is in the video description!

[@remconet]

Yeah I know, you want people to pay for it. Besides the point most people online share codes for free willingly (it is open source after all that relies heavy on other people's efforts as well like the rfid library) I don't like the way Patreon works. I was willing to pay $10 for your efforts to gain access to the codes but but after a few clicks it became apparent Patreon was going to charge me EVERY month for that amount + for every entry you create. To me that's just too much. I'm sorry.

[@PlayfulTechnology]

remconet And that's completely your choice! If you're a hobbyist, feel free to copy out the code by hand from my videos. If you're running an escape room business, buying a prop like this would normally set you back well over $500, whereas I'm teaching you how to build it yourself for $10. Patreon charges you a *max* of $10 per month, and only in those months in which I publish a new puzzle design. That money helps pay for the time it takes to create more puzzle videos in the future, which I will continue to make completely free for everyone.

[@MQGT]

Where and if you can get all the code for this program somewhere.

[@AMGamez20000]

I am trying to make an escape room puzzle in unity and i am using an arduino for it the main trouble i am having is getting all 3 of my sensors to read in real time and send it to unity if an tag is read because the tags id would be linked into the objects in unity need help.

[@dtran288]

Hello! May I ask where to buy that black adapter thing, where you connect the colored wires to the Ethernet cable? Thanks!

[@PlayfulTechnology]

Search for "RJ45 breakout" :)

[@briantouf6163]

Hi I would like to buy this installation how and where i can find it i'm from France!!!

[@Beejinator1]

Looks great! I think some of the code isn't ready yet. Can you let us all know when it is so we can visit you on Patreon?

[@PlayfulTechnology]

Hi - thanks for the comment! I've uploaded the full accompanying code listing, wiring diagram, and additional documentation for the first two projects to Patreon and they should be available to any Patreon at $10 or more: www.patreon.com/playfultech

[@KrazeeKraftZ]

Great tutorial, thanks, I will be visiting your patron as soon as I can find the required electronic components, all your eBay links are not working, not sure if it's because I'm in Australia or the seller is out of stock???

[@princessjaphiamariecabigas3581]

Hello Sir. I have a very important question. I just wanted to ask what kind of wire you use to connect the RFID to the Arduino. I am asking the wire that are color gray. Hope you can respond to my question. Thank you!

[@PlayfulTechnology]

That's an ethernet patch cable.

[@paufenollosa]

Someone know where to buy this ethernet female cables with the jumper wires?

[@PlayfulTechnology]

e.g. www.aliexpress.com/item/1005003232075106.html

[@kimberlyhoward5585]

Can i program this to work for one RFID card?

[@hipbunny5901]

Alistair, Great video. Thx much. A couple Q's.. Are the antenna's in RC-522 or PN5180 uni, bi, or onmi directional? You noted distance or read range of apprx 15cm for the PN5180. Is this straight up above card? Is there an area read range? I'm working on a build where I need more plane area. Also, can I run multiple PN5180's in series to create a greater area for tags to be read? thx!

[@PlayfulTechnology]

The radiation pattern from the antenna extends both above and below the antenna, but it's not truly "omni" directional- you'll get much better read strength if the tag and reader are parallel and axis-aligned. You can't run PN5180s "in series" as such, but yes you can have multiple readers attached to the same MCU and treat them as separate inputs.

[@hipbunny5901]

@@PlayfulTechnology Thx much for the reply. Any thoughts on readers that could be used if ya wanted a tag to be read in and defined area? Say 12"x 12" or maybe 24"x12". The above distance can be small distance

[@Lennings82]

i get "error: 'dump_byte_array' was not declared in this scope" Is this a function he made or is it inbuilt in Arduino?

[@zambonni]

The same thing happened to me. Trying to figure out why......

[@bryantbaird3794]

Hey, great stuff! Quick and simple question for ya, does the Arduino receive power from the 5v pin, or does it have another external power source? I'm not familiar with the software that you're using and wasn't sure if it ignores the arduino power source by default. Thanks! I'll be looking at your Patreon page next :)

[@vincentads5153]

Hi Alistair. Thx for this great video, i leart a lot for my internship project (I m making a system controlled by an Arduino uno, with 3 rfid readers and 2 lcd screens) ! Just a question : if i put a rfid tag just in the front of one of my readers, is my Arduino gonna write the same message on the lcd screen for any reader which reads the tag ? (and else, how can i do that :P in the program i mean). Thank you in advance !

[@DocktaLove]

Do you need a specific power source for the maglock or can the Ardurino give enough power to do this?

[@PlayfulTechnology]

DocktaLove As a general rule, you should always use a separate power source to protect your Arduino. Maglocks like the one shown require 12V; it's possible to plug a 12V source into the Arduino power jack and the inbuilt regulator will adjust it down to 5V for the board, but 12V will still be available from the VIn pin. However, the Maglock draws a lot of power, and will likely cause spikes when turning on and off that could damage the Arduino. Best to use a separate power supply with an appropriate rating for the load and tie the ground to the Arduino ground. Or, use a completely isolated power supply controlled via an opto-isolator. The Arduino is a microprocessor - the voltage sourced from its pins is a *logic* voltage used to indicate on/off - it's not a voltage to power appliances. It's a complex subject so hope that explains some!

[@DocktaLove]

Playful Technology sounds great, I'm a total noob with this stuff, do you recommend any specific power supply? I signed up for your patreon page but there weren't any suggestions for that piece of equipment in the papers

[@PlayfulTechnology]

DocktaLove Powering your props is a massive topic with lots of things to consider. I'll try to put up a tutorial that covers the main things to be aware of but it might take more than one video!

[@robertlim8202]

Hi Playful Technology, is a really cool puzzle. By the way, Using the RFID puzzle, if the player get the wrong reader, the arduino play a show funny avi or any video clip on a small monitor. how do you make it?

[@astvensk5833]

HI Alistair, great tutorial I have been pulling my hair out for weeks now trying to get multiple RFID readers to work and this looks like it might work for me (hopefully). I have been trying to get 8 readers working I know you mention you have managed 5 readers but is there any limitation apart from the crossover over the wireless ranges that would restrict this? e.g. If i position the sensors in a "star pattern" e.g the arduino being central and the sensor spreading out from this leaving a similar space as you have and the wires are all short enough +/- 20 cms, do you think this will work? or is there another limitation..? Also I have I have seen another tutorial (using a different library ) where all wires share the same PIN except for each MISO line which has it's own pin (IRQ lines are also used and connected together). Not sure if this approach is going to work as it seems a little strange having all SS Pins connected together....but do you think this would work and might possibly get around the device limit? I was about to throw away all the kit I have bought until I saw your video, so you have given me hope :) Once again thank you!

[@PlayfulTechnology]

A Stvensk Hi, thanks for the comment, and good luck with it! I would advise you to start off with just a single reader as I did in the video, ensure that works, and then gradually introduce more. I'm not entirely sure what the cause of the problem I encountered with >5 readers on a single Arduino was - it could have been too much current draw from the Arduino pins (which you can easily correct by using a dedicated power source for the readers), but I think it was a timing issue on the SPI interface. Debugging was hard because the reader behaviour just became erratic. But the approach I show here should work with up to 4 readers just fine. If I was to make a puzzle with 8 readers, the way I'd probably do it is to use two Arduinos - each controlling 4 sensors - and communicate between them using I2C, setting one as a master and the other as a slave which just sends the values of any read tags back. See here if you're not familiar with that: www.arduino.cc/en/Tutorial/MasterWriter

[@astvensk5833]

Thanks Alistair I was thinking of using I2C but I have gone through quite a few Nano's that I now have "welded" to protoboard with solder! (I really need to get better at soldering!) trying to get this to work. I'll give it a go as you have done and let you know how I get on, and thanks once again for your videos they really are great, much better than all the other tutorials I have been following for the last few months. If I end up with no hair after doing all of this do you do create paid puzzles or is it only a hobby?

[@akashverma479]

Sir, if i want to increase strength of RFID dectector then what i have to do ..? Please tell..

[@PlayfulTechnology]

Use a different chip, such as a PN5180 which is based on vicinity sensing protocol (ISO15693), not proximity sensing (ISO14443)

[@davidmcallister9752]

I keep getting this error when I try to use the example: WARNING: Communication failure, is the MFRC522 properly connected? Scan PICC to see UID, SAK, type, and data blocks... Everything is plugged in exactly where it is supposed to go...any suggestions?

[@trexnfabianndenis]

Is it difficult to connect this and make this communicate with escape room software? Do you have a video for this? 🤯

[@joshuas.3296]

Hey, I love your video! Is there any way I could get the entire code that you just showed so I can import it for my project directly?

[@byronasds]

Hello Alister, First of all i love your videos 😍! I am about to biuld something similar but i need to have 6 rfids and placed quite a distance apart (at least in pairs). My thought is using common ground and reset and a trigger pin between them when both rfids are placed correctly. Do you think it would work? (I am gonna try it but wanted your opinion before i start)!

[@PlayfulTechnology]

I'd say 6 is about the limit of the number of readers you can reliably place on a single SPI bus. The problem is that, as you add more readers, the overall capacitance on the bus grows, the voltage level drops, and it takes longer for a signal sent from the master to make the round-trip to each sensor and back again. This all degrades the signal strength and, if the response on the MISO line is not received before the clock cycle, the data is lost. What I've tended to do for large multi-RFID installations is to group readers together into batches of 3 or 4, each with their own Arduino controller, and then wire those "slave" controllers together to a master controller over I2C. I currently have this set up with an array of 16 RFID readers and it works well.

[@mepsd]

Hey mate how can i connect to multiple RFID readers with raspberry pi?

[@PlayfulTechnology]

Sure - you would use the same SPI protocol and approach.

[@bwo924]

I've found myself watching a lot of your videos lately and even ordered a couple pn5180 boards that you mentioned in another video. I may be diving in over my head trying to use RFID in my first Arduino project but I'm trying to use an RFID to turn on my motorcycle's electronics so al Ii have to do is press the button to start the engine. if i could get some basic code that ihave to manually enter my own UID but it would output a true or false signal that would be the simplest way to do it

[@davidcousin5731]

Hello, thank you very much for sharing your knowledge. Excuse me, I'm trying to create a educational chess to teach my students everything they can do with programming, electronics and much more... Do you know or could you guide me if I can connect 64 RFID readers, these will be for each square on the board. chess and that each piece is read and its reading updated to keep track of each move and play. Thank you in advance and congratulations on your work!

[@petersophiecarey1692]

What are the cables, connectors, wires used here. Anyone got names or links to where I can buy these. Need to extend the sensors around a room.

[@alexandrugroza839]

You could use some internet cables for this purpose and solder them directly or you could try dupond conectors and jumper wires

[@christiank7990]

Hi, a newbie question: you use CAT cable for wiring. Are the connectors custom made, or can I buy them somewehre?

[@PlayfulTechnology]

Christian K Hi. Yes, I'm using RJ45 connectors on a breakout board similar to this - rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F282518159661 - except I bought the RJ45 connectors and boards separately and soldered them myself, which is cheaper than buying an assembled module. It means you can use cheap, standard Cat5 cabling for any arbitrary data/power lines running between components in your project, which is hugely convenient!

[@christiank7990]

Thanks for answer and your great videos!

[@af22man]

what is the hardware you are using to go from ethernet to serial? also what is the switch you are using to power off the maglock

[@youtubak777]

It's still just a standard SPI (not serial). As a cable he uses cat5e, but the protocol is not ethernet.

[@maximax7056]

Is it possible to have 9 RFID readers and if so what Arduino board would I use

[@PlayfulTechnology]

Yes, definitely. Although when I've done large numbers of readers, I typically wouldn't have them all connected to a single Arduino. Instead, what I do is to have a number of "slave" Arduinos, each responsible for only 3 or 4 readers. And then I have a master Arduino controller that polls all of the slaves, as in this wiring diagram: raw.githubusercontent.com/playfultechnology/arduino-rfid-MFRC522/master/documentation/Mega%20RFID_bb.jpg . Using this setup I've had up to 32 RFID readers in a single prop.

[@maximax7056]

@@PlayfulTechnology Thank you

[@escaperoompuzzles]

Good video. There may be some issues when you will try to put RFID marks through 4-6mm material.

[@PlayfulTechnology]

Yes, you're right - RFID signals will carry through a couple of mms of wood/glass/plastic without problems but not much more than that, so you'll want the mount the sensors as close as you can on the underside of your prop's surface to get the best detection. Reliability is also strongly determined by the orientation of the sensor and tag - you'll want to make sure that the sensors are mounted exactly parallel to the tags to get the best detection. One way to do this is make grooves or mounting holes on the prop to make sure players place the prop containing the tag in exactly the best position to be detected by the hidden sensor underneath.

[@escaperoompuzzles]

Have been fighting with that readers for 4+ years. And found some balance . The best result was 11 readers with one controller: kzbin.info/www/bejne/b3XMfGydeLiejM0

[@cartelcrusader]

What program are you using to view the schmatics of the setup?

[@PlayfulTechnology]

fritzing.org/home/

[@dasyesu99]

Hai Friend. I am doing one project with 2 RFID boards. My doubt is, if i give the connection as per your video, is it possible to give different program for each RFID and to get different output to operate 2 solinoid valves?

[@youtubak777]

Yes, it is.

[@MinefighterLP]

Is it possible to use 5 RFID Readers on a RPi 3 B+? Where do i connect these Chip Select-Pins?

[@youtubak777]

Yes. Connect them to any free GPIO pin.

[@romainperso8575]

Hello I am French so I am sorry for my English... A make a puzzle with 2 rfid id In the monitor, each reader identified the good tag But the puzzle don't resolve...

[@OhYa1337]

READY TO JOIN PATRION, but first... Hello, I am in the Philippines & just getting started with all this. I just bought an Arduino Uno and 5 RC522 rfid sets. This video is a bit old, so before I sign up on your patrion, I would like to make sure, will I be able to use the code with 5 RFID RC522 on my Uno? I know $10 doesn't seem like a lot there, but here that's 1 days wages, So it's better to check first if I can do what I need to before I spend so much. Thank you

[@meisterlampi]

Thank you, this is a very nice video, like your other videos! I have one question: In your version you have to reset the Arduino manually so that the puzzle can be solved again. But is it possible that the puzzle could be solved again as soon as you remove one RFID tag from a reader? Specifically, the lock stays open as long as each RFID tag is on its reader, but closes again as soon as at least one tag gets removed from its reader. But it will open again as soon as the tags are on it's reader again. Is this possible?

[@PlayfulTechnology]

Yes, sure. So, the code at the moment demonstrates what is called a "latched" solution - once the correct conditions are met, the puzzle changes to the "solved" state, and then remains there forever. If you want to change that, the first thing you'll need to do is remove the infinite loop in the onSolve() method: while(true) { delay(1000); } The next thing you'll need to do is add an onUnsolve() method, to lock the lock again: void onUnsolve(){ #ifdef DEBUG // Print debugging message Serial.println(F("Puzzle no longer solved!")); #endif // Re-lock the lock digitalWrite(lockPin, HIGH); } ...and call this method from the main game loop if the solve conditions are not met: if(puzzleSolved){ onSolve(); } else{ onUnsolve(); }

[@meisterlampi]

Thank you again, I will try it the next days ;)

[@paulinacarrillo8150]

Someone knows the name of the serial app that he use or something that I can use on a macbook?

[@PlayfulTechnology]

I do! It's the serial monitor that comes as part of the Arduino IDE. Just go Tools -> Serial Monitor. www.arduino.cc/en/Guide/Environment#toc12

[@AaronMayes]

I've been trying for a few days to make this work, I've followed Alistairs updated video and wiring diagram from Patreon which includes two logic level controllers, and I can get all of the RFID chips to each work independently if I remove power from the others, but as soon as I try and have two or more RFID readers running concurrently then only one is recognized in the serial monitor and the others always produce "WARNING: Communication failure, is the MFRC522 properly connected?" I thought it might have been an issue of bad connections so swapped to solder, that didn't help. Tried providing each reader with its own independent 3.3v power supply, that didn't help. When turned on, all of the RFID readers have their power light on, and they never go out, I read that they should be flicking on and off as the controller selects between them, does this provide any insight as to what the problem might be? Thanks for your help strangers :)

[@PlayfulTechnology]

So, as it happens, I recently made a new build based on this design but using a *lot* of RFID sensors (36, to be precise). And because I didn't have that many in my stock drawer, I had to order some more boards, and I encountered a similar problem with these new boards that I'd never seen with the original design. After some research, I think I know what the problem is: So, the point of the SPI bus is that you *should* be able to have many devices all connected to the same MOSI, MISO, and CLOCK lines all the time, and the master device (the Arduino) specifies which one it is communicating with at any one time by pulling that device's Slave Select line LOW. When a slave device's Slave Select line is HIGH, it should "stay quiet" - putting its pins into a high impedance state so that it does not interfere with the communication. *But*, it seems that some of these cheap MFRC-522 clone sensor boards are not "well-behaved", and sometimes cause chatter on the MISO line even when their SS line is high. This is what causes the noise and erroneous readings when you have additional units connected. To find out if this is the same problem as you're experiencing, try connecting the MISO pin to GND through two 10k resistors, then use a multimeter to take the reading from the midpoint between them. When all readers are disabled, it *should* be a floating pin, and constamtly read half of the VCC voltage (i.e. 1.65V). If however, you see logic HIGH (3.3V) or LOW (0V), it means that the readers are sending signals on the MISO line when they shouldn't be.

[@AaronMayes]

Hello Alastair, Thank you for the very detailed response. My boards are cheap Ali express specials so that could be the case, if they are sending chatter over the miso line is there any solution other than trying different readers? Thanks so much again

[@PlayfulTechnology]

@@AaronMayes Yes - there's a couple of different ways - based on the same basic idea, which is to "disconnect" the MISO line on all readers until it is required. So, instead of simply looping around the slave select pins for each reader and setting them LOW, you need to loop around both the slave select *and* the MISO lines. To specify which reader has its MISO line connected to the bus, you could use a multiplexer (e.g. CD4051) to switch between them. Or you could use a tri-state buffer (e.g. 74AHC1G125) that disabled each reader's MISO line unless its SS was pulled low. Or, to take a different approach, you could use a port expander (e.g. PCF8574) and specify a unique dedicated MISO pin for each reader as part of its constructor, so you were explicitly separating each reader onto its own bus.

[@AaronMayes]

@@PlayfulTechnology Hello again, Thanks again for your very detailed explanation. This is all very new to me, I'm new to the escape room business and this is only the second arduino prop I've made from scratch, so at first glance that all seems quite complicated but I will go off and do some research about the different options that you mentioned. Might be easier to try and find some better readers! Thanks again for all that you do, without your videos I wouldn't have known where to start.

[@PlayfulTechnology]

So, you're right - this is a relatively complicated system if you're still a little unexperienced. I have plenty of other simpler Arduino projects for you to work up to get more familiar! There are of course alternative "off-the-shelf" RFID solutions you also might want to look into. However, the reason I always encourage people to learn how to create their own puzzle prop controllers is that you get complete control to set the behaviour and the way in which players interact with it, you get a better understanding of how it works if you ever want to change it or if it goes wrong (and systems in escape rooms *do* go wrong, but if you built it in the first place you won't be at the mercy of a third-party to come out and fix it!). And it's incredibly satisfying!

[@agnonwolf9646]

Hmm i constantly get the "WARNING: Communication failure, is the MFRC522 properly connected?" bug with most if not all of my RFID's. I know the solderings are solid (cause i have redone them many times xD) no frosting, craters of imperfections, i use 22AWG wire running to 4 readers, the farthest reaching wires

[@PlayfulTechnology]

Well, easiest way to troubleshoot would be to start with, say, a 10cm cable length and work up. Make sure you're definitely plugging the SPI wires into the right ports and that you're using 3.3V not 5V. Do you have any LEDs lit on the reader?

[@bigbro348]

I've got some issues wiring the rc522... When there is only one connected to the arduino threw a breadbord, everything works fine. But when all RFID are connected, nothing work. I've got some error messages said that rc522 are problably not well connected. Can somebody help me please ? Thanks!

[@PlayfulTechnology]

That unfortunately is one of the problems of breadboard testing... the connections between components simply aren't good enough - you really need to use screw or solder terminals to ensure good conductivity between the readers.

[@davidmcallister9752]

I downloaded it and it did not work for me. Had lots of errors when I compiled it. Not sure what I'm doing wrong.

[@PlayfulTechnology]

Hi David - oh no! If you let me know what those errors are, I can help you fix them.

[@davidmcallister9752]

@@PlayfulTechnology Got it compile, but I think the wiring is a little messed up. I'm just trying to set up 1 receiver and when I run it, its giving this message: Reader #0 initialised on pin 2. Antenna strength: 0. Version : Firmware Version: 0x0 = (unknown) WARNING: Communication failure, is the MFRC522 properly connected? Everything seems connected properly, I triple checked. Any ideas? Could this happen if I don't have all 4 connected?

[@PlayfulTechnology]

@@davidmcallister9752 And you've changed the numReaders and initialisation of the pin array in the code to only have one element?

[@davidmcallister9752]

@@PlayfulTechnology I think its the wiring itself. I eventually got it work kind of by skipping the bread board altogether and connecting the arduino straight to the reader, but it had to be held in place just right and was incredibly finicky. After googling it, it seems that its a common issue with these rfid readers. Most people that had problems said they were fixed when they solder the wiring onto the reader. I haven't tried that yet though. I'm new to this stuff though, maybe you have a better and less permanent suggestion?

[@LadyShayD]

Hey,I am new to Arduino and I just wanted to make this kind of escape room prop just because it was one of the first videos I watched and I found it well explained. BUT now I found out - and obviously a few more did - the dump_byte_array declaration is not in this video. Ok, there is this page where you want to get money with, but as you said, as a hobbyist (what I am) you can copy the code manually. Unfortionately without the last lines, the code doesn't work. I bought everything and it's now useless. I don't make money, that is why I can't pay 10$ everytime. Is there an option to only get the last lines of the code without creating a patreon account?

[@sandrinedurbize8040]

Hi, your tutorial is definitely precise and easy to follow, that's appreciated. We are in the middle of a system that gives us a bit of a headache. Our readers do not all initiate, we have a Mega as a master and 2 Uno as slaves, each Uno has 3 and 4 readers but every time we reset (as a whole) some readers may or may not initiate (thus not working with our tags and the puzzle can't be solved). This happens especially on the Uno with the 4 readers, it alway has 2 properly working but the other 2 just don't "start". Would you happen to have a solution? Thanks so much and I will check you other videos. (also I do not speak English natively so please excuse my language)

[@duncanpatti]

Alistair, you are my new best friend! I love your videos. I use escape room type experiences in the classroom as a way for students to develop problem solving skills. First, they play, then they design. Your videos are excellent in that you really put a lot of thought into the reasons for why you do what you do and I really appreciate it. ANYWAY. I am in a bit of a time constraint and I need to design a magnet placement type mechanism similar to your RFID mechanism. I KNOW that the RFID one is better than the magnet one, but for a variety of reasons I have to use magnets this time. Can you either make a video that shows the wiring/coding for a magnet type or help me via email? I would really appreciate your help! Thanks!

[@mariamibrahim6335]

Hellew, i was wondering since u seem to know how to deal with multiple rfid readers, if u could help me with a project of mine, it involves 3 RFID readers, i need the code type of question to ask for a specific tag ID. i have the 2 separate codes; the first code for enabling 3 rfid readers on 1 arduino and reading the tags, and the second code that runs on 1 rfid reader that asks for a specific tag ID, for example if (idtag =="XX XX XX XX") do something. My problem is i need to merge these 2....Any help?????? I just need to know how to ask the reader if that specific tag has passed..keeping in mind i'm using multiple readers code.

[@PlayfulTechnology]

Mariam Ibrahim That's exactly what the project I show I this video does... (except using 4 readers rather than 3) - you place the 4 correct codes in front of the 4 correct readers and the maglock unlocks.

[@thefriendliestnoodle]

Hey man... I spent an hour hand-copying the code in your video assuming it was a full walkthrough, only to find out from some buried comments that you omitted the bottom lines from this video. Of course it doesn't compile, and you redirect them to your Patreon where you want people to sign up for a recurring payment of 10 dollars a month, when all we want is those remaining few lines of code. I mean I'm all for people getting paid to do hard work, and I would've thrown a few bucks your way as a one-time thing if I couldn't find an acceptable code somewhere else (which I could). But in a community that prides itself on open source resources in order to make bigger and better things as a movement of makers, it really felt like a bait and switch. I'm sure you're aware that many arduino walkthrough videos will honestly show you everything, and a lot of them will have the full code available for free. I spent the next 2 hours trying to figure out those lines of code and ended up scrapping the whole thing because I found another complete code that does almost the same thing on github. This isn't some unique intellectual property that only you have created and have access to; in fact you're using someone else's library that they've uploaded for free for you and many others to use. I suspect that others, like me, will just feel duped by this video and find their answer somewhere else. Sure there's some good information here. I appreciate you taking the time to teach what you know. But it's not a complete project walkthrough, which is disappointing. I'm not saying that you should give away everything for free if you're genuinely trying to make a buck from internet videos. You do you. But just be a bit more up front about the fact that the complete project is behind a subscription paywall.

[@PlayfulTechnology]

I'm sorry you're feeling "duped" - if you're having trouble compiling the code, let me know what error message you're getting and I can help you. You'll notice that this is one of the first videos I created and I didn't notice that there was a line cut off the bottom of the screen capture (from memory it's a closing brace }) - take a look at any of my other videos and you'll see I always show and explain every single line of code - and that's something that, to my knowledge, is not available anywhere else, it takes time to do, and many people are happy to pay a small amount for. But for those that aren't, I'm giving you the option to just copy down and retype the code yourself - that's fine. For what it's worth, I'm planning to create a new, improved version of this tutorial over the next few months, and I'll be sure to check I scroll the code window down completely...

[@jeffdanevich6139]

I think $10 is completely fair for what you get which is a tutorial video on how to do this. Alistar I truly appreciate all of your videos!

[@thefriendliestnoodle]

@@PlayfulTechnology Thanks for your response, I don't check this account often so sorry it took so long to get back to you. I understand we all go through a learning curve of detail-oriented-ness when it comes to putting up online content so no worries if it was a genuine mistake of a line or two getting cut off. All I ask is up-front transparency in whether access to a complete project walkthrough is free or not. Have you considered a one-time payment model for people who are just looking for particular project codes? Like if people use your work as reference often I'm sure they're happy to pay $10 a month on Patreon, but what if someone just wants the code for one or two projects, rather than a full subscription? Just something to think about. I enjoy your walkthrough style, you're good at to-the-point communication and this sort of expertise is appreciated in the escape room industry and beyond. Best wishes, I'm sure I'll come across your work again sometime!

[@olivernovelles8609]

It's amazing. Thank you so much to share with us. I can't wait to start do it!! Just an answer: Can I change the lock? I mean, can I use a regular door lock without change the code? Does it have a special code or I can do it with yours? Thank you so much

[@youtubak777]

You can use whatever lock you want :)

[@olivernovelles8609]

@@youtubak777 Thank you!

[@adarshmgrocky9130]

wow its a wonderfull vedio and i like more vedios.can i get the code of this ,since i dont know how to downloard it

[@mixrhuan]

tentando fazer essa mesma leitura de tags com 4 modulos mais nao consigo . alguem pode me da uma força ?

[@AhmadAltonji]

Thank you for this beautiful explanation Can you share the code with me Instead of writing it all?

[@hasslaypakistan5949]

Dude i need ur help 😭 I want to run 4 chanel realy work with 4 rfid indualy but with one ardino uno plz helpe i m stuck .u r very good teacher and teach amazingly i m big fan of u dude

[@radiopijama5871]

I made a puzzle like this to my Escape Room (with a lot less optimal code xD) and Im going crazy, it works perfectly when connected the arduino to a PC but, when it is to a 12v Power Supply, 1 or 2 reader doesen't work until and turn it off and on again; after that it work normally. Does anyone have an idea on why this happens? I mean... I can work with this little issue but... I don't like it.

[@javiernavarroo]

Hi. Who could send me the code, thank you very much

[@alessandrotomasi416]

good! In our escape we obtained the same result in a cheaper and easier way with a simple 12v circuit and magnet switch

[@PlayfulTechnology]

Magnet switches (i.e. Hall sensors, Reed switches) are great for many escape room puzzles, but they don't discern between different objects - they'll be switched by *any* object with a magnet in them. The purpose of using RFID is that it will allow you to detect and discern a *unique* object that has been placed in front of each sensor.

[@davidaubertin7643]

I just want to say great job. What is the longest distance I can have each reader from the board , I will be using 5.

[@josematos9249]

my same question also, how long can you extend the sensor apart ?

[@marijngrashoff30]

Do note if you are trying this yourself that you get RFID tags with 4 byte ID's 7 Bytes will not work with these readers

[@Gandarufu]

Hi there, great tutorial and great code! Last time I used 5 RFID sensors I got em working with multiplexors... However, in your code you should have integrated, or at least mentioned, a "chip is absent" routine, so that the puzzle doesn't trigger when the chips aren't there any more (because the players tried them out and then put them away - their value will still be stored anyways). I used 2d arrays instead for the IDs. And For the away routine else if (!mfrc522[i].PICC_IsNewCardPresent()) I simply set their values to '0000' and triggered the changedValue as well. Works like a charm :)

[@rabbitholerecreationservic9476]

If you don't mind sharing, could you tell me how you got the sensors hooked up to the multiplexors? I have been struggling with it but it seems like a much more stable solution.

[@Gandarufu]

It looks messy, but it worked very reliably with 5 RFIDs. www.dropbox.com/s/f6dzfldwxvkb6ds/RFID01.jpg?dl=0

[@rabbitholerecreationservic9476]

Holy cow - that was incredibly helpful of you - thank you so much! Do you have the sketch also? I would be happy to pay for it, you have saved me so much time!

[@Gandarufu]

Write me a PM here on KZbin and I'll help you out.

[@michael-beck]

Would you be willing to share with me, as well? A 5 RFID layout/sketch would be incredibly helpful to me. :)

[@COSMACELF1802]

If you are going to use a magnetic lock to secure a door, you must connect it to the fire alarm panel and get a permit from the city.

[@PlayfulTechnology]

I'd suggest any escape room facility owner should ensure they are familiar and compliant with all applicable planning and safety laws and regulations. But there's not much point me describing safety requirements in detail, because the ones I'm familiar with here in the UK are likely different to anywhere else, and you should always make sure you're checking against up-to-date guidance from a reputable source, not what some bloke said on the internet ;)

[@OhYa1337]

They MAIN Entry to the room should NEVER be locked... Only the Escape...

[@matthijssluijk7431]

Hey Playful Technology, We are currently working on a similar project for our University which involves 6 RFID scanners, the same scanners you have used in your project. However, we are running into some issues regarding more than 2 scanners. Could this be regarding failing connections in the breadboard or could the length of the SS wires? Currently, they are about a maximum of 20 centimeters long. We would like some help, if you are willing to take a look at it we can send you more details/photo's and we will of course reference you in our documentation/presentation. Greetings, Matthijs Sluijk

[@ElectroLab0]

Nice project. I'm facing some issue with my RFIDs. When I connect 1 (one) RFID, then it works fine. But when I connect more than one (2 or 3), The controller (Arduino) doesn't find any readers. Get these lines on the serial monitor. Reader 0: Firmware Version: 0x0 = (unknown) WARNING: Communication failure, is the MFRC522 properly connected? Reader 1: Firmware Version: 0x0 = (unknown) WARNING: Communication failure, is the MFRC522 properly connected? Reader 2: Firmware Version: 0x0 = (unknown) WARNING: Communication failure, is the MFRC522 properly connected? Reader 3: Firmware Version: 0x0 = (unknown) WARNING: Communication failure, is the MFRC522 properly connected? Can you please help with this? Or anyone here can help me? Thanks.

[@PlayfulTechnology]

Are you powering the RFID readers from a separate 3.3V supply, or from the 3.3V of the Arduino?

[@ElectroLab0]

@@PlayfulTechnology Thanks for your response. I've tried both. Both results the same! :(

[@PlayfulTechnology]

@@ElectroLab0 Can you try adding 5V 3.3V level shifters on the MOSI, CLK, and RST lines? It might be your readers are not 5V tolerant.

[@ElectroLab0]

+Playful Technology Thank you. I'll definitely try that. Should I use dedicated level shifter IC/Modules or Resistor devider will work? What do you recommend te most?

[@playlist12ify]

@@ElectroLab0 these comments are coming when you are not connecting well the rfids make sure you connected them same as at his scheme in the video, Power supply isnt the issue here.

[@playlist12ify]

I cant find this code, can someone give me the exact link? thanks :P I try to look at the Patreon no success. I don't care to pay

[@ismail_aydemir_youtube]

PİN IRQ WHAT IS THIS PIN?

[@PlayfulTechnology]

The interrupt request pin.

[@tkke66]

Excellent and great codethank you for easy describe and exploringcan I got complete code

[@imppu112233]

That's a really dick move to leave out part of the code. I hope people realise the function for dump_byte_array isn't in an included library, but hand written code you just didn't feel like sharing. I get it that you want people to pay for it via Patreon, but you could atleast mention that fact in the video. I wasted hours as I thought some of my library was outdated or something. The pricing on Patreon is really weird and confusing.

[@hishamhisyam1691]

bro have you figure out the function code?

[@imppu112233]

String dump_byte_array(byte *buffer, byte bufferSize) { String read_rfid = ""; for (byte i=0; i

[@aurelienleniau3698]

@@imppu112233 Thx bro, it's working with this !

[@sabriilmak6001]

@@imppu112233 can u help me to tell me in which part of the code i should add this missing code?

[@sabriilmak6001]

@@aurelienleniau3698 can u help me to tell me in which part of the code i should add this missing code?

[@gameoverlords1089]

Alistair, thanks you so much for all the informative videos. I subscribed to Playful Tech and believe this is a great investment for a novice puzzle designer like me. I followed the library download instructions you provided but when I went to compile the code I got the following error message: Arduino: 1.8.5 (Windows 10), Board: "Arduino/Genuino Uno" C:\Users\Owner\Downloads\Multi_RFID\Multi_RFID.ino:22:21: fatal error: MFRC522.h: No such file or directory #include ^ compilation terminated. exit status 1 Error compiling for board Arduino/Genuino Uno. As I mentioned I am a novice and sure could use some help getting this library file issue resolved for my (4) RFID puzzle. Any assistance would be greatly appreciated. Thanks.

[@kelseyarthur6421]

Fantastic! As a newbie, very helpful. Glad you made this! Two things: I was trying to follow along with your code, and I ran into the error that "dump_byte_array" was not defined. Did you define the function somewhere else in the code, or was it supposed to be from one of the libraries? For some reason I keep getting that error. Second, you mention future video ideas! I'm working on another puzzle involving little Potentiometer knobs that I would like to attach to a mag lock using Arduino. I think I'll be using 3-4 knobs, that when turned to a certain angle, will unlock something. These are the knobs: amzn.to/2zK6Noo. I think that could be another cool video topic for the future!

[@PlayfulTechnology]

Hi Kelsey, thanks for the comment. The dump_bye_array() function is defined right at the bottom of the code listing, but I think it might have got cut off slightly in the video :( Sorry about that, but you can download the whole code from www.patreon.com/posts/object-placement-15681373 . And thanks for the suggestion about potentiometer knobs - I've used them in this puzzle! ;) kzbin.info/www/bejne/rYeZgJKBn9FrZ7c

[@adarshmgrocky9130]

can you sent me the code plz

[@oPunkko]

jesus loud lock fucking hell i jumped man