#402

[@likaci]

Happy wife, happy life.

[@AndreasSpiess]

True!

[@felenov]

I really appreciate the Swiss humour and the problem solving. Good work, as usual.

[@AndreasSpiess]

Glad you enjoyed it!

[@aldonsmith3031]

@Andreas Spiess, This is the first video of yours I have seen and I just wanted to say your troubleshooting and engineering skills are top notch!

[@AndreasSpiess]

Welcome aboard the channel and thank you for your nice words!

[@paulg3111]

Great idea using Lora. My mailbox is over 60 meters from my router but luckily a neighbour in our Siedlung close to the mailbox uses upc as well. So I connect via UPCfree Hotspot with esp32cam on latch triggered by vibration sensor. Take a photo of the mail as well and send via email. Always run to the mailbox when photo of yellow envelope.:)

[@AndreasSpiess]

Excellent idea to use UPCfree. I never thought about that!

[@deangreenhough3479]

Excellent work Andreas 🏴󠁧󠁢󠁥󠁮󠁧󠁿😁👍

[@AndreasSpiess]

Glad you enjoyed it! Have a nice Sunday.

[@gregorymccoy6797]

"Happy Wife" -- the most important design goal. Some things are universal 😀. It always amazes me that even relatively simple projects are full of tough problems to solve. Thanks for sharing with us viewers.

[@AndreasSpiess]

You are welcome! I learned something during my career: The detail is always complex, even it it looks simple from the distance...

[@electronic7979]

Excellent project 👍

[@AndreasSpiess]

Glad you like it!

[@CTCTraining1]

Excellent project and well explained as usual. Very good plan to track the battery voltage especially as the temperatures start to drop.

[@AndreasSpiess]

A few viewers are curious if it will survive winter. I will report in spring...

[@soulrobotics]

I was thinking about this for an year and i was too lazy to develope it! This is a great gear,! Andreas!!! GOOD JOB SECOND TO NONE,!

[@AndreasSpiess]

After all my setbacks I can tell you that you saved quite some time ;-)

[@EsotericArctos]

My mailbox is a fair distance from my HA hub. I'd tried RF and it wasn't quite good enough. I had not thought of using LoRa. Thank you for the great ideas.

[@AndreasSpiess]

As mentioned, I once tried 433MHz and it also did not work. So you have one more chance...

[@U8uxa8SP]

This looks like a valuable project, thanks for all the information, I always enjoy your videos.

[@AndreasSpiess]

You are welcome!

[@jstro-hobbytech]

Second post, I apologize. The happy wife concept has does wonders for my hobby. Probably one of the most important life hacks (or marital happiness lessons) I've ever learned. Especially since I'm medically retired and she has a promotion which requires a home-based office because she's in charge of the training for province wide government agency she works for here in Nova Scotia. As a side note you would love the Cape Breton highlands as a destination for your bike vacations. One of the most beautiful places on earth, I grew up here and it's beauty still makes me feel in awe and reinforces the fact of how small us as humans are compared to the vastness of nature and it's ability to create things more impressive than anything our hobby can achieve.

[@jstro-hobbytech]

@Andreas Spiess pardon?

[@AndreasSpiess]

A spammer uses my name and picture. Sorry for that.

[@Brandon_SoMD]

I may use this to get me started on building a "notify me when my dryer finishes so the clothes will not wrinkle" alarm system that I keep meaning to build. Thanks for the inspiration!

[@AndreasSpiess]

If the dryer is in the reach of WLAN you probably can use this technology...

[@reidlanham2011]

Very good to see the video of this project after you talked about it on the Ham Radio Workbench podcast which I really enjoyed!

[@AndreasSpiess]

They asked me "what is on your workbench" ;-)

[@axelhertwig8258]

Cool! If the battery is directly connected to VDD you can also use 'extern "C" int rom_phy_get_vdd33()' and save the voltage divider (and current). I usually calibrate this at 3.3V and it works ok-ish.

[@AndreasSpiess]

Did you try it? I found posts complaining it is not reliable.

[@axelhertwig8258]

@@AndreasSpiess Yes, I use it after Wifi is connected. In very few cases I get the impression that it is 0.1V off. For real decision making, e.g. power down at low battery voltage I use an recursive filter to make it more reliable. If you don't trust it, you can still move your voltage divider behind the power switch to save current and for the case the newspaper is stuck for a long time you can connect the low end to a GPIO: low for dividing, tristate for off (the ADC GPIO will be maximum at VDD in this case which should be ok).

[@MrBobman49]

How can you connect the battery directly to VDD when the ESP32 has a VDDmax of 3.6V?

[@axelhertwig8258]

@@MrBobman49 I was refering to the setup with a LiFePo4 battery. It has a maximal voltage of 3.6V, nominal 3.2V.

[@klif_n]

This is a great video! I built something similar using an RFM95 module and an ESP32 in the base unit to send text messages to my phone. It really is remarkable how far the modules can transmit. One reaches over 1000' for my brothers driveway and another about 400' thru woods and a low hill at our tree farm. As usual I have learned a few new things by watching your video. Thx

[@AndreasSpiess]

Indeed these LoRa modules work very well. I also was astonished when my gateway got signals.

[@ulwur]

@@AndreasSpiess does the transmission go through before the flap does down, or goes the panel gaps* allow the radio signal to pass through? (* I'we been watching too much Munroe...)

[@AndreasSpiess]

I do not know its pass. The flap could be one possibility

[@Medievalguy88]

I will be curious how this will perform in the winter. Do you imagine the battery or switch will be affected much by the cold? Great project and video as always!

[@Ox4C4A]

Charging a lithium cell in the cold is a big no-no, but usually low current discharge is fine.

[@AndreasSpiess]

I had a few Li-Ion batteries on the roof during last winter and I even charged them with solar. They survived, but one died during summer. So I do not know if it was the cold or the heat.

[@jmr]

All my outside sensors are currently powered by disposable cells so I have no personal experience. I know of several projects by other people however that perform well in cold with Li-ion cells and no heaters. The primary places I know where heaters are required are in high altitude balloons (edge of space) and off grid battery systems(high charge/discharge).

[@salehsalehi8433]

Nice chain of thoughts:" Not wanting to check the mail box several times in a day...". I would have suggested checking the mail box once at the latest possible delivery time, say 5:00 PM. Simple solutions are most elegant....

[@AndreasSpiess]

Unless somebody else "checks it first and removes your Chinese Packages ;-)

[@dmytr01]

I love your projects!) I like the way you explain all the things. I learn English by your lessons!)

[@AndreasSpiess]

That's great! Thank you.

[@GillesBruno38]

Toujours aussi instructif : merci !

[@AndreasSpiess]

De rien!

[@PhG1961]

Excellent project which can be adapted for many other notifying situations. Sunday morning entertainment with a few one liners of Swiss humor...

[@AndreasSpiess]

I also think it could be adapted to other situations. This is why I thought it is a good use case for a node for the new TTN network.

[@wolfgangschulter4940]

Great work, Andreas! For my solar-powered sensor project I chose the Arduino Pro Mini as main controller with AT328P running at 3.3 V. Deep sleep with RAM retention is done by sleep_mode(), during sleep its consumption is below 0.1 mA.

[@AndreasSpiess]

The AT328P is probably the better solution for a LoRa node. The only problem is the memory space for the new library...

[@MrBobman49]

The ESP32 in "deep sleep" consumes 1/10th of that, 10uA. 8-bit processors are annoying because you are always wondering if you will hit the memory ceiling.

[@EmilyLoebl]

I've had a similar project on my desk for months. Using one of the Cubecell boards that has a tilt switch connected, to send a state change, transmits thru TTN, then goes back to sleep. Right now been sitting on my desk that beacons once a day for battery levels. Going on months now and battery level has been amazing. This may inspire me to finally just get this project done as the previous mailbox motion sensor was recently destroyed by ants.

[@AndreasSpiess]

Other viewers also used a Cube cell. This seems to be a very good solution for such a sensor.

[@NETBotic]

I've had a lot of fun with LoRa on short range links inhibited by structures, like this.

[@JC.72]

i am surprised that lora can go thru metal like enclosures like this mailbox.

[@AndreasSpiess]

Thank you for confirming my observations!

[@flokibyarian6832]

Ich werde sofort das gleiche machen! Danke😁

[@AndreasSpiess]

Wart noch das nächste Video ab ;-)

[@michaegi4717]

As allways this is a genious project. There are libs available to store in eeprom/flash at rotating positions. They also use the latest valid value, so if you have problems with flash you will get information from saving before. Warning: most Flash-Memory fails writing at low temperatures.

[@AndreasSpiess]

I was not aware of those libraries. And also not about the problem of low temperatures. Good to know. You will see in the next video that I had to take an entirely different route ;-)

[@michaegi4717]

@@AndreasSpiess This flash issue was a problem at my work for quite some time. Now I'm suprized that I found several ESP32 data sheets with operation temperatures down to -40°C. Now I really wonder if this works. I'll put one of my ESP8266 to the freezer to check if they really can handle negative temperature.

[@michaegi4717]

@@AndreasSpiess A first test in the freezer looks good. It seems that the values are normaly written to FLASH.

[@thedarkglovemusic]

I have been working on one of these on and off for the past year but using Xbee. I managed to get quite a lot of battery life out of deep sleep but I didn't even think about actually triggering power instead of waking it up! Also I'm really pushing the limit of the Xbee range so definitely need to get on board with LoRa. Thanks again for your work and videos.

[@AndreasSpiess]

XBee has much less "punch" but much more bandwidth. If it works, it is a good solution. But in my case it probably would stay inside the box...

[@thedarkglovemusic]

@@AndreasSpiess I also needed to put the antenna on the outside which wasn't ideal.

[@vinny142]

So, why not use one of those self-poweroff circuits? Opening the mailbox pushes a button that latches the power "on" and when the messages have been sent the ESP turns itself off. That would have no standby current at all.

[@AndreasSpiess]

I thought I used exactly what you described in this video. So I am not a very good teacher :-(

[@MrTohnitan]

@@AndreasSpiess indeed. Do you also have a design for an RTC triggered circuit? You can get away with the built in RTC with a pro mini, but once you have a circuit with an esp and multiple sensors you want to turn everything off between intervals

[@henningklages861]

Very good idea. Thanks for the video. I use the Browan motion sensor. It works dine so far.

[@AndreasSpiess]

Cool!

[@Dennis-hb8tw]

Great! I tried to look up Video #388 (At 6:00) for the power switching prototype board but found only your video about the summer break. Did I missed it?

[@philpearce3248]

You will find the Mosfet switch on video #389 at 11:55

[@AndreasSpiess]

I did not mention the right video. Sorry for that. And thank you, Phil.

[@Dennis-hb8tw]

@@AndreasSpiess Hey Andreas! Never mind. Is it possible that the Andreas below is a bot/fake?

[@AndreasSpiess]

Yes, it is. I reported it.

[@Moonlight0551]

Well done, as usual you have researched this very well and marital harmony is very difficult to attain. It would not work in Australia where the newspaper delivery guy(person) drives down the middle of the street and flings the paper from side to side. It might end up on the road, caught up in a tree or on the roof and block your guttering if really unlucky. But, it would work for letters in the mailbox(apart from the junk mail) as we have mostly trained our posties to put the mail in the letter box.

[@AndreasSpiess]

The price for a newspaper is very high here (500$/year). So we probably would not accept this "treatment" ;-)

[@Sylvan_dB]

I suggest one more component in the transmitted message: a sequence number. That allows the receiver to detect a missed message. More thoughts: A periodic message might also be good to confirm operation, but then you either need to send a reason or deduce based on time (every morning at 05:00 is unlikely to be the mail carrier) that it is the automatic message. Finally, sending battery level in each message could be convenient.

[@AndreasSpiess]

The battery level is transmitted in the message. I agree, a periodic message would be a good thing, but would need a very different setup because here, the ESP32 is completely switched off. You could use deep sleep to achieve that. TTN transmits a sequence number and I could check it. For this use case I anyway would go and check the box if no alarm came till the evening. So I discover the "missed" message (if I find mail and did not get a message)

[@dmrbdlln]

Why? Because I can!😀 I love this channel!😍

[@AndreasSpiess]

Thank you!

[@maufctube]

Hi. Thanks for another great video. You should add an alarm on the exception that the postman leave the door opened. It could be an additional function, just to evaluate the postman work or how many shipments doesn't fix in your postbox. Greetings from Peru!

[@AndreasSpiess]

It would be easy to send another message because the ESP32 stays on if the lid is open. I could send it before it goes to deepsleep.

[@maufctube]

@Andreas Spiess Thanks!

[@permissionBRICK]

I built the same thing using a Heltec CubeCell (for super small deep sleep power draw) in my appartment, and I also added a small button inside the mailbox which sends a packet that unlocks the entrance gate through the intercom, to have a fast and easy way to unlock the entrance door when I am coming home with groceries etc. just by reaching in the mailbox quickly (since the mailbox is right next to the door). I also did it without lorawan, instead I used plain LoRa.

[@AndreasSpiess]

These Cubecells are very good for such applications. And you are right, no TTN needed. But I anyway have a gateway on the roof ;-)

[@allcrafter3747]

I modified a Doorbell and now it works perfectly with an ESP that sende ne an E-Mail

[@AndreasSpiess]

Good idea and very simple! If the doorbell signal is strong enough.

[@Bookohms]

Wondering... After these 2 years how is the battery working? Updates? Great engineering skills!

[@AndreasSpiess]

I have no statistics. But I had to replace the batteries once since it is running.

[@dentarinc7214]

I built something like this with RF24 module and small Pro-Micro Leonardo. It uses a transistor latch circuit to power it on, sends the signal to a receiver, and shuts off as soon as it gets the acknowledgment, or after so many retries. Powered by 9V battery. Has been running for 2.5 months so far.

[@AndreasSpiess]

Good design if you do not need the reach of LoRa.

[@marcusdiemer4420]

You mention the prototype board in video #388 (5:57) ... but I think this reference is not correct? Where can I find it?

[@AndreasSpiess]

it is 389

[@mitsosliak]

What number are you referring at 5:55 time mark? 388? If yes, I can't find any useful info at that video about the shut off circuit.

[@AndreasSpiess]

You are right. It is video 389. Sorry!

[@mitsosliak]

@@AndreasSpiess is there a #389 video? I can see 388 and then 400.

[@AndreasSpiess]

@@mitsosliak You are right. Obviously, I renumbered the videos. It is 400 now.

[@iggman18]

Could you add a telegram notification when the wife alarm is cleared, so you know if the mail was picked up while you were out? What about a clear button in the mailbox itself? You wouldn't want to have two people checking the mail if they arrive at different times.

[@AndreasSpiess]

The design of the "Happy Wife" box in the kitchen has no reverse channel. So in my case it is not possible without changing the logic of the kitchen box. But the ESP has all info and I could send an MQTT message to node-red to "clear" the telegram alarm. Maybe I will do it once.

[@rauldiosdado2972]

This video was like sitting next to you going through the same problems when developing IoT projects with LoRaWAN. Same problems and very similar solutions, in my case the biggest differences have been to change from TTN to ChirpStack... This simplifies things a lot, TTN V3 does not work 100% well, the ABP mode has become useless with the new changes and the OTAA mode is not well tuned yet (to do things a little out of the ordinary). Thank you very much for your videos, they always have been very useful and even interesting. Byeee

[@AndreasSpiess]

So far I never used Chirpstack. But I made some tests with a Helium light gateway. This could be interesting for our US colleagues.

[@ol-np8sy]

Salutations de Fribourg....great work

[@AndreasSpiess]

Thank you! Passed Fribourg last week on my trip to Nice ;-)

[@tim-wise]

Thanks for all you do on your channel. I've learned a lot over the past year in following you. A question about your latch circuit at 6:06- if you wire a momentary reed switch from 5v to the load in order to wake the MCU up, wouldn't that put 5v onto pin 2 of the NDP6020P in your diagram? Is that ok? I can see how it might be "equivalent" to the gate energized and current flowing.

[@AndreasSpiess]

The gate anyway is pulled to 5v by the 10k resistor. It needs to be pulled low to make the FET conduct.

[@tim-wise]

@@AndreasSpiess Yes it is. I'm sitting here staring at that and it never registered. Thanks!

[@lexandro]

I'm curious how the swiss winter affects the battery.

[@AndreasSpiess]

Me too ;-)

[@cj_clippy]

I'm curious about the board meant for powering on the LoRa module. Video #388 was mentioned, but I'm not seeing anything about the board in that video. (Video #388 is a vacation announcement.) Is there another video featuring the build?

[@AndreasSpiess]

You are right. I changed numbering and now it is #400

[@cj_clippy]

@@AndreasSpiess tyvm!

[@lint2023]

I don't think video 388 was the one with the two FETs for power on and off. Do you know which video it was. Thank you. I now see #389 mentioned in comments. Thanks.

[@dreamcat4]

very good! that was a very enjoyable video. and very useful too, because what other solution can do thisata low power, except for lora? and a great execution of this excellent example. one of my favorite recent videos here. many thanks

[@AndreasSpiess]

You are welcome!

[@davidstonier-gibson5852]

Nice solution! I keep pondering a letterbox notifier, though my circumstances are quite different (private property but no flap i.e. mechanical movement).

[@AndreasSpiess]

Other viewers use a load cell on the floor of the box to measure the weight.

[@davidstonier-gibson5852]

@@AndreasSpiess I wondered about some form of weight sensing, a microswitch and lever maybe. It would have to very sensitive but also quite robust. What's neat about your solution is the momentary ON operation, allowing zero standby power.

[@AndreasSpiess]

You could only measure weight once ever half hour or so to save energy, I think.

[@TheRainHarvester]

@@davidstonier-gibson5852 They sell flexible strain sensors that are 5" long.

[@martinp8889]

Good work.

[@AndreasSpiess]

Thank you!

[@MyGregon]

very nice video!! May I ask why you don't took a weight sensor into consideration, to detect if something is in the mailbox?

[@AndreasSpiess]

Also a possibility. But it would take a lot of space (our box is not very high) and also need much more energy because you have to check the weight regularly.

[@davidurdahl6656]

Fun video. Definitely couldn't do this here in the southwest US where it gets up to 118 degrees for 4 months.

[@AndreasSpiess]

Well possible. And inside the box it probably would even heat up more.

[@davidurdahl6656]

@@AndreasSpiess exactly. And it looks you have a have an admirer.. lol I'm guessing the last two comments are not from you?

[@AndreasSpiess]

You are right. A troll uses my name and picture

[@davidurdahl6656]

@@AndreasSpiess people suck...

[@dengyun846]

@@davidurdahl6656 It's funny because I just found a bag of haribo left in my mailbox from a friend the other day (same Swiss standard-issue box as Andreas has) and it was actually quite warm, nearly melting, and it was only 20ºC (=~70F) out. @Andreas btw, since you're careful about your location, the map screenshot at 1:00 is unambiguous, fyi

[@mmoci81]

Hi Andreas, one of 2 best channels for starting with LoRa I manage to find for now. Regarding problem with Joins and deep sleep... would it work with ArduinoProMini in V3 setup you show here?

[@AndreasSpiess]

It uses the same processor as the Arduino Uno. So it is the same problem with memory.

[@wjn777]

Welcome back from the summer break Andreas - very nice video and thank you for sharing. The IRF7317 combines a P and N channel MOSFET in one small surface mount package, I used one of those generic breakout boards to make it a little easier to work with. This is nice if you want to save some space in your enclosure. Thanks to your previous video, I used this concept as well to make an ESP8266 run in a doorbell without deepsleep. Interesting using LoRaWAN - but considering all the effort, is it not easier to do a point to point connection from the mailbox notifier to another ESP32 that converts the incoming LoRa message into something like MQTT? I did that for a ESP32 weather station, and it is working very well, through many walls at approx. 30 meters

[@AndreasSpiess]

Thanks for the tip about the IRF7317. It seems to be a good solution. Concerning LoRa /LoRaWAN: I prefer LoRaWAN because I already have a gateway (and I wanted to have a show case). If you have no gateway, your solution is better.

[@remifr4sw322]

@@AndreasSpiess Just a Question about LoraWan Gateway : I've made a mistake with Dragino LG02 (no more compatible with TTN v3 and LoraWan) what do you advice me as gateway (also for students so it can be an all in one a a Raspberry Hat), no Helium/crypto need but your advice, thank you in advance - Remi

[@AndreasSpiess]

@@remifr4sw322 Any gateway is good. You have to decide if it has to be indoors or outside. Mikrotik has probably the cheapest Outdoor gateway. Just check the frequency before you order.

[@hoctrimededebutry8655]

Hello from france !! excellent video as usual 😀 I'm looking for a mailbox notifier and your solution is nice !! unfortunately, the LorA's cards are no more available (Amazon and AliExpress stores)... Do you have any other references ? Thanks a lot one more time for the quality of your job !!

[@AndreasSpiess]

Maybe you use a Heltec Cubecell. They are also quite power efficient.

[@jstro-hobbytech]

What an awesome idea Andreas. Unfortunately the small communities in Canada do not have post(people), we have a small manned(personned?) building up the road. Our slots are so small that there isn't room for a sensor. I guarantee if there was room they'd let me do it as I'm the only one who receives packages with Chinese text on it haha I'm also friends with the postmaster. This would be a perfect use case for the unused flag pole and Lora module I have. We have the same weather as you and I've been planning to use it as a central point for esp based communication on my property and it's line of sight to the small post building haha. You're as funny as you are smart Andreas. Great video.

[@AndreasSpiess]

Thank you! You could offer the postman a small box with the same content and a button on top. Maybe he would do you the offer to press it when mail arrived for you ;-) I never was in Novia Scotia. The only place I was in Canada was Toronto.

[@jstro-hobbytech]

@@AndreasSpiess I lived in Toronto in grade 2. The cape breton highlands are amazing. Well you live in Switzerland so it's probably the same views. Off topic but I'm a bit of a history buff. Armies crossing the alps on foot in the winter has always bewildered me. I cannot wait to see your awg voltage boost project. I got excited when you mentioned it in your vacation parcel arrivals video. I've been waiting to buy a new awg because of it. The ability to output an adjustable ac sine wave for psu experiments has been a (nerd) dream for me since learning dc basics. I want to study different rectification circuits and filters and create power delivery circuits that are all at different voltages and such. An adjustable ac bench supply costs more than all my lab equipment and on hand ics, components and my thousands of leds combined. Plus my 3d printers. Not my guitars though lol, I was never happy with the guitars I had until I started this hobby. So to say I'm excited for that video is an understatement.

[@jstro-hobbytech]

@Andreas Spiess pardon my friend?

[@AndreasSpiess]

A spammer uses my name and picture. Sorry for that.

[@AndreasSpiess]

For the moment I do not know when the amplifier video will air. I have to search for a good use case…

[@cedricpod]

you are one of the best

[@AndreasSpiess]

:-)

[@originalmianos]

For audio notification I have an esp32 with an I2S decoder and class D amplifier module, speaker and a miniature 240 to 3.3V switched mode PSU in a little case. I wrote a little app that plays a specified mp3 from an internal web site based on an mqtt command from node red. This way I can ring the door bell from an RF bridge, play an hourly ding like a clock and or any other sound. With an enclosure designed with audio in mind and reflex ports and a reasonable little speaker, a normal person could not hear the difference between mechanical bell and my box. People actually comment on the old style mechanical two tone bell.

[@AndreasSpiess]

Cool project! I once did a similar thing but with an MP3 player module instead of a I2S interface. My viewers were enabled to trigger a messages back then...

[@jmr]

I took the easy route and used a wireless window sensor. I have a plastic mailbox with line of sight though.

[@AndreasSpiess]

Then it is much easier. A window sensor is a good decision in this case.

[@BurkenProductions]

0:30 that's why you have mailboxes on your house door and not outside or inside the entrance.

[@AndreasSpiess]

The postman is more productive like that.

[@wayne6220]

Very good video, thank you.

[@AndreasSpiess]

You are welcome!

[@Daniel-vd4mk]

What antenna have you used for the transmitter / receiver ? I’d appreciate some Ali link? Thanks !

[@AndreasSpiess]

I do not post antenna links because suppliers often change what they sell. So a "good" antenna can be bad a few month later. The only possibility to be sure is to try and test them yourself (I made videos about that). Or buy from Digikey et al.

[@Bandedegarantie]

That's creepy I was talking about this with a friend a couple of days ago, using LoraWAN

[@AndreasSpiess]

You you have a blueprint ;-)

[@chris_ea]

Great, how about set a paperthin like weight sensor to be sure if and how MUCH mail is in the box? By preventing the postman opening wrong box? Do you know any weight sensor?

[@AndreasSpiess]

I am sure you could use a weight sensor. Most of them use strain gauges. That is another method. I never tried it.

[@chris_ea]

@@AndreasSpiess or resistant mat between two leading fabric?

[@fortheregm1249]

wife send you to get the paper ? now i see why you were motivated to make this :D one thing i like about Esp8266 vs esp32 is that it can just read input voltage and there is no need for using a GPIO or voltage divider. I've ran bare esp8266 with direct lipo charged to 4.1v, if anything it runs better and gives stronger wifi signal. not tried that with ESp32 as i like them too much to chance it. when battery life and size is critical i use an optoisolator connected to a GPIO in between the voltage divider (just to make myself feel better). great video as always, VERY clever decision to use the reed switch, the choice didn't even accrue to me, I thought a radar module would have been the best choice.

[@AndreasSpiess]

Good point about the ESP8266. I do not know if the ESP32 has a similar functionality. But the voltage divider was not a big thing.

[@fortheregm1249]

@@AndreasSpiess I've wasted a lot of time looking for an equivalent command to ADC_MODE(ADC_VCC) for esp32, but from my understanding its not supported not due to lack of code/library but hardware design. pity because its such a nice feature that lets you add battery monitoring to all your project for free.

[@raywright4012]

Would be interesting to see something like this powered by a supercap, and recharged by small solar panel. Perhaps a weather station on the mountain and it uses a small solar panel to charge. Then send using Lora every ten minutes, the weather conditions. Maybe 2x 50F caps.

[@raywright4012]

An infinity sensor. To last maybe 10 years. What minimum size cap would you use? Minimum sized solar panel? Would be a fun project.

[@AndreasSpiess]

You can combine Solar and super caps. Maybe not for this dark place, but my awning protector uses such a design. So far I never made a video about that topic. Just on supercaps for a Raspberry Pi.

[@raywright4012]

@@AndreasSpiess thanks for the reply Andreas. And of course thanks for making all these wonderful videos. They are very helpful. Woukd love to see a Lora sensor on the mountain using the super caps and an energy harvester. Maybe small solar panel. One that you will never have to replace the power. But is such a device possible? Probably, with a large panel. But we would like a small box with small panel on the box. Anyway, thanks again for your amazing videos.

[@daedalus5483]

Would a PI Pico have been a suitable alternative to the ESP?

[@AndreasSpiess]

I never tried deep sleep with the Pico. So I do not know.

[@daedalus5483]

@@AndreasSpiess Thank you very much for your answer. I asked because in video 370 you didn't seem to know of a use case for it yet in your verdict, and in this video you talked about valuable space for libraries.

[@FourthWayRanch]

we have those too, except there is a generator for a capacitor that works on the door opening and closing, no battery required

[@AndreasSpiess]

Like the Enocean switches. I am not sure how hard my flap would open to generate enough energy. The door opening seems to be better to generate enough energy.

[@simoncollins6650]

Hi Andreas Another great video , shame I don’t have a post box my mail though the front door. 😁 I would just comment that the Heltec cubecell board AB02 and other cubecell products can use deep sleep and gpio as wake input with very low current.They can also be set in the board config menu to store network credentials so no rejoin or loss or counter values. I now use these a lot. Not Esp32 but use combined an MCU/SX126x chip set (ASR 6501/2) new products look to use (ASR 6601). Also my comment on TTN V3 over last 3 month it is stable has been very good. Simon

[@AndreasSpiess]

How do you program these boards (which IDE, libraries)?

[@simoncollins6650]

@@AndreasSpiess what is your preferred email address to contact you on . Quick summary Ardunio IDE could use others, libraries are supplied on Heltec site/ GitHub based on Semtex / stackforce standard node libraries . I can give more info and comments by email too long for here . Simon

[@AndreasSpiess]

You find links in the description on how to contact me.

[@brianballard905]

With all the issues of joining the network and given the distance is very short, would it not be easier to simply go "peer to peer"? The mailbox powers up and transmits it's simple message. In your house a Lora board attached to a Pi listens for a message then does it's thing. No need to use the TTN etc. I use this system for monitoring a treatment plant for my water supply about 1km away. Just a 5byte "chirp" every 10 minutes or so.

[@AndreasSpiess]

You are right, it would have been easier. But I needed a motivation to migrate to TTN V3. And this one was a perfect fit if I see how many problems I had to solve...

[@xraken7197]

Is a double MOSFET circuit really necessary to power the board with a signal? I've tried with a low Vgs N-channel MOSFET like RFP30N06LE and it works with the 3.3V signal to drive the MOSFET. The spec sheet diagrams for that MOSFET show that a minimum gate to source voltage of 2.5V should suffice.

[@AndreasSpiess]

You are right. I think I mentioned in this or the other video. It often works if you use the right FET.

[@LinuxGalore]

Had similar issues myself, ended up using a solar powered WiFi security camera with built in human detection. Total cost was about USD$50. The software allows me to setup a virtual security fence and when a human enters the area around my mail box it triggers the camera to send a picture to my phone. I ended up writing a security program and using one of my running Raspberry Pi servers as I was a bit wary of using an app that has servers in China hooked up to a security camera.

[@AndreasSpiess]

Lucky you! Since I life in a very crowded area Security cams have a hard time to only detect meaningful signals. I have one on the front door, but it still creates false alarms. Even with the electronic fence :-(

[@wahidyak]

Is it still possible to use public gateways? Or we have to personally own one?

[@AndreasSpiess]

Yes. Public gateways work the same way as with V2

[@arva1kes]

i would add additional switch for mailbox - if whole door is opened it will reset alarms for "new mail" automatically ;)

[@AndreasSpiess]

Already done (see next LoRa video) ;-)

[@AndreaIannucci]

I think that you theoretically also be able to turn off the LED if you put another reed switch on the door you open to collect the mail, if that open (and/or close) you turn of the led and you can then consider the mailbox as empty :)

[@rishabhgusai96]

That newspaper case will be an exception.

[@AndreasSpiess]

You are right. Maybe I will add this switch in the future

[@AndreaIannucci]

@@rishabhgusai96 Absolutely true, but maybe since you're getting the newspaper, you would also check if you got more mail :)

[@bluefishactcl1464]

Nice. I think is time for me to add Lora to projects

[@AndreasSpiess]

Definitively a valuable technology for certain applications

[@id513128]

Is it possible to use a light interrupter with a coded pulse? I'd love to apply this with a mailbox in my condominium since there's no mailbox flap to trigger the tilt switch and an ultrasonic sensor might not work with a thin letter too.

[@AndreasSpiess]

The problem of all "active" sensors is the power consumption. If you can power from mains your solution should work.

[@docarmodeiras]

Just mount a litle Door ínside the gole.

[@id513128]

@@AndreasSpiess Thanks for your reply. I might only run once an hour from sunrise till sunset. And maybe use some kind of replaceable battery like 18650 or 14500.

[@id513128]

@@docarmodeiras The problem was, just like Andreas, I don't own the mailbox but the HOA does. And the box is actually just a drawer stack with each other. I don't think installing a flap will work though.

[@Tom-ku8bu]

@@id513128 How about something like a scale or just an button that is beneath a second bottom? or an Solar panel with an controll light sensor that turns on when the pannel is covered and the controll light sensor has light? Maybe an transistor logic could trigger the lora board on.

[@bobw3398]

Instead of having the reset switch on the box in the kitchen to turn off the notification light, why not add a second reed switch to the mailbox door. So, when the mail door has been opened and the mail removed, it resets the system?

[@AndreasSpiess]

Already done! Many viewers suggested this enhancement.

[@binthem7997]

Man I love your videos. Wish I had this channel available during university studies. It's teaching me new stuff and solidifying theory I've read. Keep it up! Greetings from your sibling country Sweden!

[@AndreasSpiess]

Thank you for your nice words! Indeed, some viewers think that I am Swedish...

[@binthem7997]

@@AndreasSpiess Yea I know the feeling :-D Happened several times that people believe I'm from Switzerland. I can't blame them because of the many similarities.

[@jensbovbjerg9284]

Hi Andreas. Which LoRaWan version did you use when registering the device in TTN V3? i.e. MAC V1.0 or higher?

[@AndreasSpiess]

I used 1.0.3. this seems to be the recommended one for V3

[@Uncle-Duncan-Shack]

Ah, greetings Andreas. The Sunday morning tech news from Switzerland. This has turned out very well, I like it a lot. It is also highly customizable and what you have done is an excellent departure point to get started with. Thanks for the video, have an awesome week. Kind regards, South Africa

[@AndreasSpiess]

Thank you! Indeed this project was intended to be used as a basic node for the new V3 network. Have a nice week, too.

[@soumitradey8208]

Excellent Sir

[@AndreasSpiess]

Thank you!

[@Ryanboy2020]

I wish I knew how to do all if this. Where does one start??

[@AndreasSpiess]

I would start with a simple project. Then you can go on with what you learned. But it will take a wile...

[@zyghom]

OK, superb as usual Proposal for improvement: distinguish if the mail is the newspaper or box from China - "because on this channel we always want more!" and btw: when will Andreas start using (and sharing) Home Assistant? ;-)

[@AndreasSpiess]

So far I did not use Home Assistant. I use Node-red because I think I get more control. But you never know ;-)

[@zyghom]

@@AndreasSpiess that is very mature answer Andreas ;-)

[@miked3655]

Hi Andreas, love/hate your channel. So much great content and ideas that my wallet is complaining!! I do have a question about this sketch. I have run into this issue in the past where the example sketch, yours included, is written for the EU868 band. I have to use the US915 band and from everything I have noticed they are very different in how and what you need to code. I am still learning this but it appears that there is much more control over the EU868 band over the US915. For instance you cannot specify what SF you want to transmit on, at least I have not found anything that will work. And in your sketch the "EU Like Bands" portion fails when I try to compile it for the US915 frequency, " 'MAX_BANDS' was not declared in this scope" is the error I get. I assume it is because that function is not allowed or required when using the US915 band. I have not tried commenting it out and trying it as I do not know what it is trying to do. I have not seen anyone using this option of the LoRa library. Is this section important?

[@AndreasSpiess]

Yesterday I learned that this sketch only works for the European TTN. I was not aware of that. I have no solution for the US, unfortunately.

[@miked3655]

@@AndreasSpiess Thanks for your response and this is my biggest frustration with LoRa, trying to convert a very customized EU868 sketch to a US915. I think LoRa is used much more in Europe and hence so much more project available examples to go by. If I figure something out I will let you know!

[@McTroyd]

Simple and elegant, as always. But what about the sub-freezing winter weather? I was under the impression lithium batteries won't last when they're frozen...? 👍

[@AndreasSpiess]

We will see. The Li-Ion batteries on the roof survived the winter. One died during summer. So I do not know if it was the cold or the heat. In the mailbox there is no charging. On the roof I have solar power. I still have the possibility to go for primary AA cells if it does not work.

[@dynamicdevices-iottraining7801]

Interesting to hear your thoughts on the TTGO/Heltec power consumption. I spoke to Aaron @ Heltec about this a couple of years ago and he sent me their Wirestick Lite which he told me was much better. Seems to be the case. They also have some CubeCell boards now which seem very good. Have you tried these?

[@AndreasSpiess]

I made a video about one of their boards. It is very good for low power applications.

[@damedaE90]

Nice project :) I do the same but with Wifi and modem sleep to measure the time the lid was opened..So i can guess if it is chinamail or just bills ... Also i measure, if my mail was taken out of the mailbox xD Saves time :) Greetings to Switzerland

[@AndreasSpiess]

Cool! Because you can distinguish the bills you can start to work on how to avoid them ;-)

[@isheamongus811]

Power form energy of flap open? Put prop not enough

[@AndreasSpiess]

The device has batteries.

[@isheamongus811]

@@AndreasSpiess Then it won't die

[@mfx1]

Add a second switch that sends a "collected" message to reset the light when the door has been opened then you don't have to remember to clear it manually.

[@AndreasSpiess]

Good idea!

[@JC.72]

after all these years with esp8266 and esp32, there is still no pre-made boards which has the efficient deep sleep issues resolved?

[@AndreasSpiess]

I made video where I compared the boards. But here I needed one with LoRa. It seems that the Cubecell boards are quite good in deep sleep.

[@MrBobman49]

@@AndreasSpiess I made the same project as you with a door switch. To solve the power problem, I removed the FTD231 UART, the 3.3V LDR from an ESP32-Dev board, replacing it with a 3.0V LDR. Running it off a standard 18650. I used one of the "wake pins" on the ESP32 to send battery voltage to my cell phone via Twilio.

[@RixtronixLAB]

Nice video, thanks :)

[@AndreasSpiess]

You are welcome!

[@Thamli]

The external temperature will affect the battery life the most. Specially in Switzerland. Great video though. I've smartified my letterbox with a height sensor an esp8266 with esphome and home assistant to deliver the messages on my phone/smartwatch, but the battery doesn't last a week. Is worked so fast that the postman was at the neighbors when I went outside for the mail. As I don't receive many packages anymore, I'm not using it for now.

[@AndreasSpiess]

I will see if the battery survives or if I will switch to primary AA batteries. Getting a long battery life was important for me, but measuring the height is also an interesting possibility.

[@NavySeal2k]

A second reed switch on the door could reset the happy wife LED automatically. Just saying if you want a new toy soon? ;)

[@AndreasSpiess]

Good idea!

[@KarimAkors]

i did the same with an battery powered wlan cam,s standby movement function, every time post gets in i got an email with "real mail arrived" and a 3 second video. one time a squirrel was storing there stuff in there and as i got home i got around 31 mails as soon i connected with my home wlan.

[@AndreasSpiess]

Interesting animals. Unfortunately, we do not have such animals around our homes. Too crowded for them, I assume.

[@esunayg]

happy wife happy family 16:26 :)

[@AndreasSpiess]

True!

[@traderdaniel4749]

Is it possible that someone writes a Tutorial for people like me? I don't know how I should build this by my own.

[@AndreasSpiess]

I did some tutorials a few years ago and maybe Google helps you to find one. This video is just an update.

[@ats89117]

My mailbox is similar to yours, but I have a different solution. One of my neighbors has a very aggressive rottweiler. This dog hates the mailman, and this sentiment is mutual. When the mail arrives, all hell breaks loose and I know it is time to get my mail...

[@AndreasSpiess]

That sensor seems to be cheaper than mine (at least for you) :-))

[@astoops]

I laughed myself sick ovr your comment. Well done!

[@taranagnew436]

i have a mailbox that dosn't have a flap but opens sideways, how would i get notified when they close the mailbox after they put the mail in?

[@AndreasSpiess]

You have to find a place for a sensor which switches when the mailbox is closed. Maybe you have to find another way if the door is open for a long time.

[@miked3655]

I have been playing around with your code and trying to adapt it to my use. I want the deep_sleep low power mode and to not have the LoRa module always do a JOIN when it comes out of deep_sleep to send a new message. However, using your code I find it always tries to do a join every time it comes out of deep_sleep and never actually joins. I know you are using your code for a power off situation but since I saw the deep_sleep option there I thought I would try it. I found a few things that would not let it compile at all, resolved them, and now it does "work" where by it cycles through the trying to join (but rarely ever does ) and always tries to join after a deep_sleep. The loading of the LMIC structure doesn't seem to do anything stopping it from doing a new join. Did you try your code in deep_sleep mode?

[@AndreasSpiess]

Maybe you watch my video about TTN V3 migration? There I explain the dilema.