Make your own very crude Walkie-talkie with an Arduino

JLCPCB SMD assembly coming soon: jlcpcb.com
Here is how to fix my Walkie-talkie: • #279 How to debug Ardu...
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HACKED!: TV Remote becomes an RF Remote: • HACKED!: TV Remote bec...
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You can find the schematic & PCB design on EasyEDA:
bit.ly/2xX307A
bit.ly/30J6GX6
Or you can download it here: / 28513352
Websites which were shown in the video:
tmrh20.github.io/RF24Audio/
github.com/nRF24/RF24Audio
www.ti.com/product/CC8520
en.wikipedia.org/wiki/Samplin...)
In this project I will be showing you how I tried to create a Walkie-talkie with the Arduino development board and the nRF24. Along the way I will present you the functional principle of a Walkie-talkie and at the end create a kind of working prototype.
Thanks to JLCPCB for sponsoring this video
Visit jlcpcb.com to get professional PCBs for low prices
Music:
2011 Lookalike by Bartlebeats

[@greatscottlab]

Here is how to fix my Walkie-talkie: kzbin.info/www/bejne/j3uVZpiHh8ebl7M Thanks to Andreas Spiess for helping me :-)

[@LaserHeNe]

Hi GreatScott, as always, great job done 😀 I have also tried to built that walkie talkie and with tips given by Andreas seems to be work.

[@lynes2peters438]

Hey Great Scott! You didn't answer to his question, wouldn't you like to meet him and test the fixed system on a motor bicycle tour with him?!

[@jiltomathew6589]

kzbin.info/www/bejne/h5mzhJeEZ82inbc Please explain about this video

[@pressreset]

Neat. Cool it got fixed. :) I was thinking about doing this. You really don't need any large data rate to transmit voice. If you build in a vocoder, it will allow you to extend the range significantly, and get the transmission rates down to around 6kbps per channel. If you split it with fewer bands, even lower datarates. That's how a lot of walkie talkies work, and it's how GSM/LTE systems transmit voice. Half rate GSM is like 5Kbps per channel, and full rates I believe anywhere from 12/16Kbps dual. It also allows you to put basic encryption on the signal. Cool project. Nice video. 👍

[@chubbypolarbear23]

GreatScott! I love your videos and have a mission for you. Please please please make a video about the low power library. You will be able to simplify it so well! Thanks!

[@cosicasF9]

You seriously need to be sponsored by a marker pens company...

[@alexm761]

bic !

[@zeero4ever]

This video is sponsored by Schwan-Stabilo. Fine liners and text markers in a variety of colors starting under $2.

[@MrFrazierNation]

So true

[@pahom2]

Why do you think he is not sponsored by them already?

[@ColinTimmins]

Watching him write schematics and data is really enjoyable. I'm very neat with how I write, but he does it with so much ease.

[@luminumlx2604]

"How many arduinos do you have?" GreatScott: *yes*

[@mrnettek]

:-)

[@kjyhh]

0:30 around 30?

[@meliekorn]

Hi I think problem is that you put speaker directly to PWM output. I think you should use filters to make signal smoother.

[@erbro]

That is my guess too... a simple rc filter could help a lot. I also think the word smoofly should be added to the English language :D

[@SimranjitSinghMehra]

Agreed, I did some similar. Output was crap. Made a crude class A amplifier using LM317 IC and output was clearer albeit the IC required a heat sink because of poor design

[@lazar2175]

@@SimranjitSinghMehra How did you make a amplifier out of a voltage regulator?

[@ericblenner-hassett3945]

I would have thought you would need a voltage divider on one side of the speaker so there would be an equivalent of half voltage either side of the PWM signal to get the speaker to go in AND out.... It worked for me when I tryed a similar circuit years ago ( pwm to sound out )

[@user-dj1hy6zc6q]

And he needs a 8 kHz low pass filter before the ADC and another 8 kHz low pass filter before the speaker/speaker amplifier. 16 kHz sample frequency is only capable of 8 kHz audio reproduction (Shannon Nyquist sampling theorem). By not having those low pass filters, all of the PWM noise, high frequency PWM harmonics, and clipping (high frequency pops) is drowning out the useable audio signal. Signal to noise ratio is really bad without filtering out the unusable frequencies.

[@mrk3ma1]

Hi, correct me if I am wrong but don't you need a LC filter after PWM output of the arduino before hooking up output to a speaker?

[@siliconrobot6522]

I think that rectangular signal is not the best wave form for audio output to speaker. Perhaps if the wave form is more sin like, the quality can be improved a little bit.

[@HaengemattenLeben]

Like in a Class D Amp To filter the PWM Signal

[@systemofapwne]

I just was going to mention this too. The PWM signal is just poor and results into that kind of artifacts without a proper filter. For an even better quality, I rather would go for a dedicated DAC though.

[@MaulikParmar210]

Correct ADC requires DAC on other end to rebuild non quantized signal, that's why audio is clipping

[@Slartibartfas042]

Illegal to operate, but would be working with a few more steps. First of all you of course will have to kind of filter the PWM signal to get some decent audio quality. OK - one could argue the mechanical slowness of the membrane of your speaker could do that for you. But what is by far worse you did drive the speaker with DC BIAS! That means, the membrane of your speaker will already be pulled or pushed against one mechanical limits of the full stroke length, that is why the system did sound so badly! Use a proper dimensioned C to block DC Voltages and you most probably will have a working system, if you want to do it the proper way then you'd have to have a proper filter (lowpass filter and buffer amp) then to drive the speaker. Apart from the fact that you will not be allowed to use such a system legally in most states all around the world since you then would operate a 2.4GHz transmitter without any EMC safety tests being applied. And maybe not even being respecting the bandplan or maximum allowed transmitting power of your country. And maybe not being respecting minimum allowed distance for transmitting devices/ antennas from any kind of human livings and some of their best parts (well, just in case their best parts may also include their brain and are not only their reproductional systems which I don't want to decide here). So, nice idea and it could easily work if it was done properly!

[@kreynolds1123]

I'm surprised there wasnt any debugging to find where the audio is getting messed up.

[@MetinFTW]

Andreas Spiess (the guy with the Swiss accent) made a video on debugging the project: kzbin.info/www/bejne/j3uVZpiHh8ebl7M

[@olivierconet7995]

Excellent video, especialy because of a failed project. The best way to learn. So many youtubers are showing projects that clearly work by chance and never talk about failures. After all, real life engineering is all about failing and starting again 😁 Keep going !

[@Sir_Trip-s-A-Lot]

Thank you Scott... I have been looking for this for last 4yrs... Numerous time I thought of building one..but due to lack of knowledge and skill, I could not. This will be a very helpful for my first draft. You are a savior.

[@giocic94]

100 mV, gain of 100, so the output can reach 10V. But you opamp works between -3.3V and +3.3V, so the output will saturate. You can try to reduce the gain (e.g. 30) and try to use big resistors... For example 10 Mohm for the feedback resistor and 330kOhm for the input resistor of the inverting opamp

[@luigif6643]

Same thing i thought, it just sound like a saturated sound. A quick view with the oscilloscope should make the problem clear...i would go for a simple dual stage amplifier and a low pass filter at the output.

[@thegoodhen]

He uses a potentiometer in the feedback, so he can tune it till it's good... I think this shouldn't be a problem.

[@andreidicu2882]

upvote this so he can see

[@drank4069]

Always wanted something like this. Thanks for all your great projects!

[@peterellis2764]

Hi pal, I must say this and none of your projects you have failed in is by no means a fail. Your inspiration and passion will drive you and your EE cult much further with success when this happens. I have to say your PCB layout and routing on this board looks great and your really getting the hang of it, even though I do like your perf board designs lol haha. Keep up the hard work and thank you so much for your channel !

[@user-dj1hy6zc6q]

The amp seems to be clipping (you can see it clip in the oscilloscope recording), you seem to be missing a DAC on the receiver, and 16 kHz sample rate is only good for 8 kHz audio (should be okay for speech); so you need a 8 kHz low pass filter before the ADC and another 8 kHz low pass filter after the (missing) DAC in order to remove all of the useless higher frequency noise and distortion which you are otherwise hearing which is above Shannon Nyquist frequency. Refer to Shannon Nyquist sampling frequency theory. I would love to see you fix it.

[@projects4996]

I always love whatever you do, Whether it's a failure or success. Addicted to your videos waiting for another Sunday ☺️👍

[@mohitt2390]

May be he is catching alien audio signals 😄

[@BeamDeam]

Yea probably from area 51 😂

[@Bob3519]

I bet if he added a cross cut saw blade and a Speak and Spell®. He could have transmitted past the planet MELMAC!

[@mohitt2390]

Area 51 😂😂😂😂😂

[@wantomek]

I love, that you upload projects whether they're successful or not. I hope that with the help of the community, you ultimately succeed, and share a follow up video.

[@Racov]

I very much admire you for sharing (and pain editing videos) projects which didn't work out well. Is a great way for me to learn and skip this time consuming trials. Thank you and keep up the good work 👍

[@cxmmax4265]

why not do like your class d amp with the comparator to got a 1 or 0 logic level to send data and on the reciver part build a h bridge (with death time controller for power consumption) and a lc filter ?

[@aidaneloff5357]

Please continue with this project! This is a really functional build, I will definitely build one 🤩

[@kekecjan]

I had the same idea to use nRF24 to transmit sound but i never tried it yet and now you motivated me to do it haha. I really like you projects, especially when you making your own PCB. Again thank you for this project, i enjoyed it.

[@JonathanRansom]

I was just googling this to see if it was possible to build something for my kids. Thanks for saving me the time!

[@2000Divyesh]

I was using the same library for the walkie talkie project i was working on recently.. i didn't design the microphone circuit and pre-amp for the speaker.. I bought them as modules.. put them together.. used the very same sketch.. they worked fine..

[@kreynolds1123]

@@highkicker11 agreed it sounded like a lot of clipping.

[@miawgogo]

@@kreynolds1123 Yeah, i noticed when he was looking at the signal in the oscilloscope that it was clipping

[@avamander.]

Same, it worked nicely for a basic intercom for me.

[@alansimons141]

Like others have said, your problem is probably the PWM "DAC". To verify, you could save some ADC data to flash and replay it on your computer, to verify it sounds good. You could make a better DAC with several data out bits from the Arduino plus a resistor network.

[@talowbo]

Way above my amateur electronics head, but I just love watching smart people to really smart things... well done my friend.

[@JonathanKayne]

Hey just wondering what the name of the background soundtrack is. I don't mean the intro listed in the video description.

[@lazar2175]

Hey man, looks like you need a DAC and this could possibly work out. Please do a update on this, i think it may be a quite easy fix.

[@Shahbs]

that sign off dialogue through the transmitter!!!! 😂😂😂😂

[@felipechavez673]

I like that you never give up a somewhat complicated project

[@askquestionstrythings]

I was thinking about this for a project but due the really bad audio quality issues I was thinking of blending an arduino with cheap kids walkie-talkies. Now I'm rethinking my plans and following the concept you are working on.

[@abhihellow]

output the pwm data on the 4 digital pins(map the data) and use a crud R2R ladder to output a analog signal of 4-bit crude DAC circuit

[@mmmhorsesteaks]

If only there were some easy, ancient technology that didn't rely on microprocessors to transmit audio wirelessly... Some sort of frequency modulation technology or something... We can but dream ;-)

[@Loundre3]

Yeah...RF in all its analog glory is one heck of a abusive bitch.

[@ksoma228]

2 plastic cups and a string :)

[@defaultuser000]

Basic FM transmitters are dead simple to build and there are super simple demodulator chips available for the receive side if you don't want to design that half. Just find out what frequencies are legal to use in your country without a license and pick one that's easy to design for.

[@mmmhorsesteaks]

@@defaultuser000 27Mhz band seems to be ok in most countries. Give it three more years and we won't be able to blink an led without calling 5 api's on our IoT enabled NeXtDuino's. This is getting out of hand. Not everything needs a microcontroller.

[@kk1l]

@@defaultuser000 It is one thing to use general communications frequencies with commercially available equipment. But using non-commercial home-brew transceivers is not legal unless you are a licensed amateur radio operator and use it in those bands.

[@tomgeorge3726]

Hi, have you tried powering everything from 5V and leaving the NRF connected to the 3.3V reg? Have you got a scope trace of the audio out so you can get some idea of where the distortion is coming from? Have you checked your 3.3V supply for noise from the NRF plus unit needing quite a bit of current when transmitting?

[@johnmiller4859]

Based on things I did many, many years ago, I think two things may be going on. 1) You set the gain on your op amp circuit too high and/or 2) Input Independence mismatches causing distortion. Over all, beautiful work. Thanks for sharing.

[@cprn.]

Also, I think you shouldn't have set the volume to max. Depending on what the library does underneath it might be responsible for the low audio quality. I'd check the lowest and middle values as one of those seems to usually represent 100% loudness in all of the radio libraries I ever worked with. High values usually mean some kind of boosting.

[@chicabomb5933]

I KNEW IT!! I SAID ON YOUR FACEBOOK POST THAT IS WALKIE TALKIE

[@greatscottlab]

Congrats :-)

[@willwho2512]

Done this project with the same library before. On speaker side, I hook up a PAM8403 module which works on 3.3v. The audio is still a bit noisy but it gets louder and more recognizable.

[@alexejrm]

Do the adc reads negativ voltage? I think you need to drive the 0 voltage level to +2 volts with a transistor and then amplify the signal with opamp but with lower gain for better quality.

[@jaspersun4909]

PWM signal is emmmm.....better be called digital signal,but audio is analog signal....you need a LPF to convert PWM signal to analog audio signal or use a DAC + PA directly...

[@rich1051414]

Wait... no choke on your PWM output? No wonder! Look at the output on a scope and it will become clear why it sounds like crap :P

[@jankomuzykant1844]

Choke ? And what speaker is ? ;o)

[@rich1051414]

@@jankomuzykant1844 Not one that small with a PWM that slow. The speaker isn't sufficient.

[@jankomuzykant1844]

@@rich1051414 You forgot mechanical inertia. I think it's first episode - with the problem. Now I'm waiting for GreatScott's fix ;o)

[@rich1051414]

@@jankomuzykant1844 At a high PWM frequency, you can get away with no choke. Also, a larger speaker with more mechanical inertia also helps. Here, with the PWM frequency being so low, there is NO WAY that little speaker can do anything substantial to the signal on it's own. A Class-D amplifiers needs AT LEAST a 40khz signal to IDEALLY produce no audible distortion from 20 to 20khz, and that is assuming there is enough inductance to 'connect the dots' on the pwm signal. It's best to not rely on the speaker, because you have no idea what present or future type of speaker will be hooked up, or any speaker at all for that matter.

[@thegoodhen]

@@rich1051414 Nah, its okay. You can PWM into earphones and you won't hear the distortion at 16kHz. Been there, done that. This is something else.

[@cesaredwing]

Keep up! I like your honesty. My respect and admiration from the Dominican Republic.

[@JaapioNL]

Have you tried to trouble shoot it by sending a some wave at a fixed frequency by passing the mic, amp and adc?

[@big_b_radical3985]

Did you filter before digitizing to prevent aliasing?

[@peterellis2764]

Maybe using the other op-amp in the LM358 as a Sellen key filter. Your on right path with this Big B

[@frankhobsonKJ4CDM]

I would have liked to have seen him use the lm856 instead. On the audio I couldn’t help but think the microphone could be some of the problem.

[@robjal]

Correct me if I am wrong but you encode it from analog to digital with an ADC and you decode it using PWM? Should you not decode it using a DAC? The sample frequency should be twice the maximum frequency and in case of voice a sample frequency of 10 kHz is more than sufficient.

[@danuuu101]

Exactly what I was thinking I don't understand how PWM generate the required analog audio signal and why not use DAC

[@notatoyotacamry195]

@@danuuu101 Variable duty cycle that's tied to the ADC value. You'll get an audio signal after you apply an LC low pass filter. Look up sinusoidal PWM or PWM DACs. I think GreatScott did a video on those, actually.

[@jmaguilarr]

did you try to use a little reference for the adc to help with the noise ?

[@jamesdinsmore9022]

I recall the concept of audio companders (compression of the audio bandwidth before transmission and the expansion of it on the receiving side); this is a good thought experiment and thank you for trying.

[@pramitkumarpal4828]

Great job Mr.Scott. Can you make a detailed video on making a pll fm transmitter. Thanks for all the awesome videos!!

[@RadOo]

Well you can get such a FM transmitter with stereo generator for at least I have one of those for about $3

[@ZeroMass]

Before I had mp3 I made a crude fm radio transmitter, had my own station within the boundaries of my property.. This project also looks fun..

[@SnipeR-02]

Wait, you got nrf24l01 pa lna working both ways? I have to touch the antenna to transmitt anything, but can receive no problem.

[@RomanoPRODUCTION]

GreatScott has a great sense of humour 🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊🕊

[@HaengemattenLeben]

Maby a LC filter beheint the PWM Signal ? Like in a Class D Amp :D

[@HaengemattenLeben]

I do not see any in your plan

[@lazar2175]

DAC is the solution, but a LC filter may work out.

[@tunahankaratay1523]

@@lazar2175 LC filter builds a DAC basically. I would use an RC filter in combination with a LM386 amplifier to keep it small and simple. The more important thing which Arduino cant handle properly is high frequency sound signals. I would use a proper high sample rate 8 bit or even 10-12 bit ADC.

[@lazar2175]

@@tunahankaratay1523 No, no it does not build a DAC. Like it's name suggests, it filters the pwm signal. The dac converts the pwm to a AC analog signal suitable for playing back in the speakers. He has a video on it, go watch it.

[@technixbul]

@@lazar2175 I would say an RC filter instead and LM386 ... but why at first place Arduino? This is a very simple task for 2 transistors on transmitter and 2 on receiver and you can beat audio quality and range with a whole magnitude

[@marcmoreaux]

Hey, I find lots of knowledge in your videos. Thank you very much ! Maybe you could record the digital audio signal out of D10 and D9 on a txt file and share it to analyse it in python (matplotlib, librosa and sounddevice). Working with audio, I have often found myself with saturated and encoded signals that were eventually legitimate... Thank again for your channel :)

[@partypillz3268]

Do you have a simple code/sketch we could all play about with.link,I cannot find it in the description

[@PeterMMMMM]

Awesome project. Thank you posting it even if you didn't get ideal results. It makes feel better about my failings.

[@philipkunkler6341]

Hey Could you make a video on how to build an 230v dc to 230v ac pure sinewave inverter?

[@angeljurado7941]

That is a lot power. Electrical safety should be the first priority. Be careful. However, if you want to do something similar. You need an IGBT H-bridge configuration. Transfer DC to AC. The modulation will be SPWM. That show the same parameters of sine wave. Important: dead time between IGBT switch. You need to implement diferent reference voltage to IGBT. Finally, you need to desing the protection systems. If you are more interesting the 3 phase speed control motors do that, but you can do that for monophase.

[@leollo1998]

Maybe a low pass filter for the speaker

[@pierreretief]

I want to say thanks for uploading projects where you failed as well! Still very interesting and really gets you thinking...

[@NorekR]

I am looking for a simple pcb design program that you recommend?

[@Jeakerek]

It souds like pc speaker ghostbusters intro from commodore 64

[@peterellis2764]

Hahahah OMG that brings back some memories hahah

[@clifffton]

Impossible Mission!

[@technixbul]

not even close :D

[@R3MIXMODZ]

Not all projects are a success. Maybe the comments can improve it too!

[@fredmutua7684]

Great comment!👍

[@vagnerfischer9107]

Nice honesty from Scott , lol !

[@OsoPolarClone]

Would using an ESP 32 and a its faster clock speed help by having a higher sampling rate?

[@manojachrekar7327]

I wanted to make something like this for so long..😋🤘🏻🤘🏻 Waiting for part 2

[@insanitywolf05]

a guy from Ukraine running the channel "VirF Live Productions" has built a pair of walkie talkies based on the nrf24l01. You do not necessarily have to understand russian, since wiring schemes are provided in the vids too

[@apinkeh]

it is possible to do the similar project with esp? which more powerfull and have built in wifi that can transfer up to 7mbps (according to datasheet)

[@dimitriosvlamis8696]

What if you used an external ADC with bigger resolution and using the DAC of an esp8266 or esp32 for recreating the sound?

[@power-max]

Why would you use an arduino for this project? This is a perfect thing to experiment with analog electronics and modulation techniques. Build an FM bug transmitter but tune it to an ISM band like CB radio.

[@RadOo]

I wouldn't use FM for this

[@dtesta]

This seems unnecessarily complicated. Why not just use an esp8266 and espnow? Cheaper, easier and less components.

[@maycodes]

Esp8266 range is low

[@titi101]

I need a arduino compatible board that works with negative tempatures. What should i use?

[@deepakchauhan6872]

Hey, Friend Can you tell me How you directly convert Schematic into pcb...

[@chaitanyagoswami2393]

I think that analog transmission will be much better than digital transmission for walkie talkies. Since audio quality will also be much better. What do you think ? Tell me if I'm wrong...

[@baldbadger7644]

so why not pure analog circuit... Arduino is kind of overkill

[@pascha4527]

its a little bit harder to do bi directionnal walkie talkie in analog tho.

[@mmmhorsesteaks]

@@pascha4527 plenty of 27Mhz analog walkie talkie circuits floating around on-line. Doesn't seem to be rocket science :-)

[@100ksubscriberwithnovideos8]

Too many engineers here....wrong place for me😂😂😂

[@MultiSigen]

I was wondering the same thing, that’s why I was reading the comments to see if anybody else thought that.

[@stuffingpicturmotion7726]

may i know why to use an arduino for a crude walkie talkie? cant we make a crude analog radio?

[@atitan9421]

Hey do you have the a BOM file or Pick and Place File for the assembly or a list of components i would need, i am not particularly versed in this field so that information would be help me a great deal.

[@kowkaybin]

Yo, don’t just hook up raw PWN signal to your speakers.

[@acynder1]

Warning, any comunication device that uses headphones or equivalents are ilegal to be used while driving on Spain's territory.

[@alexanderlepelch4075]

Hi, my project I am using the max9814 as mic input, but the audio out on the speaker sounds like chipmunk, high pitched. Any ideas why?

[@bobdehuisbaas1]

I'm so glad this comment section is full of solutions and helpful people! It would be great if you made a follow up video implementing this newly acquired knowledge to make a working system

[@shivasisdash7343]

yees this is why he is GreatScott value for name and namste from India😘😘🙏🙏

[@malgailany]

I can't believe you went to order the PCBs and parts after the breadboard prototype was a fail.

[@etienne3838]

It was the sponsor of the video. And honestly PCBs are like a couple of euros (even at that timr already) so no big deal..

[@benemmett6194]

A lot of good suggestions in the comments. One more thing to check would be the DC bias of the mic input. Without that bias set properly, the negative voltage swings would be clipped causing ugly distortion. It looks like you did consider this in your design but I didn't see it verified in the video. A good way to check this would be sending your ADC read data to an off board computer and verifying that it is not clipping too much at 0 or 1023.

[@rajeshsharma-ng3cb]

Hi can tpu tell me how to make a crude Ossiolocope using your very own stm32 as available online

[@SuperHddf]

Obviously PWM "audio" is a bad idea... But nice vid as always

[@donpalmera]

I find it interesting that all the people shilling for JLCPCB mention the $2 PCB and not the $10+ shipping cost.

[@erksampat9328]

It's still much cheaper than other manufacturers

[@erksampat9328]

​@Pilot16H It's more like $18 for 5 boards but still $3.60 per board is a great deal. Also that price is the same for sizes up to 10x10cm.

[@lazar2175]

Isn't the first order free shipping? I never ordered off of them, but i don't see it as a big problem if it is free shiping for first order, just make new accounts.

[@UpcycleElectronics]

@@lazar2175 You'd need to move a lot, as I'm sure they track the shipping address. ... I think the free shipping bit has changed. All the shill plugs have not mentioned this in awhile. I screw up too much for these services anyways. I'd hate to design, wait 2 weeks, then get stuck with 5 junk boards, redesign, wait 2 weeks.... I can etch a small single sided simple layout in 1-2 hours with toner transfer without standing up or leaving my bench. I can do a large double sided photoresist, with soldermask, and an aluminum can solder paste stencil in a day even as a partially disabled gimp. Heck, a manhattan style prototype or waterproof marker design is even faster. If all that is too much, I'll just use a razor blade and have a small board in 15 min. I don't generally like subscription services, but perhaps they could come up with something cheap that makes sense? I wouldn't mind an ultra striped down option for prototyping. If I could order a special one-off single board prototype to do iterative designs reasonably quickly and seamlessly, then order a general production version of 5-10 like once a month, or two, or even quarterly, I might consider it. I mean I don't care about soldermask, silkscreen, tinning, and I'd even give up through hole plating, for basic prototypes. That's how I design anyways already. If they had a service that was really cheap, somewhat flexible, and just sent me some cool basic designs, or useful generic SMD breakouts because I didn't order the full subscription boards allotment I might consider it. If it were possible to easily order prototypes or small production runs where I could get one or two BGA or QFN chips attached without hassles or coordinating with multiple parties, they could persuade me much more easily. Heck even attaching a TQFP with more than 64 pins can be a pain at times. I usually need to have 3 chips per board just in case I need them if it's a new design. I don't even have a BGA setup yet. That's probably the only way they could get me to sign on and really use the service. This cost per board thing is a funny concept compared to DIY. My entire dual style etching setup was less than a bill, including the 10x pack of single sided A4 sized CEM-1 from ABCfab. I still have 2 sheets of that laying around in addition to all the other stuff I've collected. My cost per board is just time. I wouldn't even carry the pocket change equivalent and call it money. ...and I believe the OP mocked me for my lack of BGA experience in the past, so I don't think I'm alone here :-) -Jake

[@lazar2175]

@@UpcycleElectronics Quite obviously it is superior to make your own, in fact i've never ordered off of JLC because my country has quite insane customs so it would take well over 60 days for me to recieve the boards. I either "borrow" large pieces of unetched boards off of my work, or i order it through AliEx, they are 5 pieces of A4 size for 2€. I also can't get FeCl3 so i have to use HCl and add 17% H2O2 to make my etchant. I don't own a laser printer so i have to go to the city and have someone print it for me, mostly losing time. But i can make boards for about 0.30€ per board without soldermask and other shenenigans. For smaller projects i still use the stripboard, and for projects that require traces smaller than 0.2mm i order it locally.

[@hightttech]

Thank you for sharing both the successful projects, and the not so successful projects. That is real life. Of course every project might eventually become a success with enough time and money, but that threshold is different for each inventor. Cheers.

[@lagkun8271]

Can you tell me how does the ic ss3002 a2qnm work please

[@RainRoseville]

Hi! not sure if you already have one but can you make videos about how to design and make our own geared torqued dc motors? I have been wanting to make my own mini motorized screwdriver for cellphone and laptop screws but there is no information on how to design the gears to convert speed to torque. Looking forward to a reply.

[@PauloHenrique-hg7iw]

limits the signal to mono remove encryption and use a smaller range or 433mhz would not look better?

[@joopterwijn]

You can not win them all, but no failure here, you learned and gained experience!

[@wyattherzog4093]

Does anybody know where he gets all of his components as in capacitors and resistors and stuff like that?

[@runforitman]

I would love to see you revisiting projects, that didn't quite work out, and improving or fixing them!

[@osamakemoo8023]

hi scott can you make a video on microaire easy start and how the system can reduce the running(or starting ) current on an AC compressor and can a big hard capacitor do the same function ?

[@2012TheAndromeda]

Thank you very much for the informative video! This will be a fun project to do.. also gives me more ideas with the transceiver! I have a question.. Would you be willing to make a video about authentic and counterfeit Arduinos and what their differences are? Because the generic/counterfeit arduinos perform more poorly and seem easier to break, even though they use the same components (Presumably) as the original one. I ask because was looking up an arduino nano and there were a bunch of generic ones on Amazon and some reviews showed they broke easy. This I experienced as well and when I compared it to an official arduino it was basically the same except PCB color and company. Also with the generic board when I output text to a screen (16×2 screen) every other letter is shifted up one bit but not on an original arduino (despite both being Atmel chips) Sorry for the long post!

[@danosdotnl]

hey hey, is your code available anywhere though? I love the receive status led!

[@PonnambalamChakkaravarthi]

Hi Scott, I brought 60W gluegun, but heat not sufficient to melt gulestick.suggest me to increase the heat.

[@rezafauzi5743]

Sir, how to drive an N channel MOSFET on the high side without IC ?

[@uwezimmermann5427]

I have successfully used an ATmega328 running off its internal 8 MHz oscillator for speach audio output to a speaker without much filtering - using a high-enough pwm frequency you should not need additional filtering. Have you looked at the output signal of your mic amplifier on an oscilloscope? Is it in the right range for the ADC? What is the sample rate of your ADC - hard to tell if you use the Arduino libraries, I know. This is a point where I would definitely consider using the hardware settings directly... Also, how is the signal for the speaker generated? connecting it as a bridge-tied load between two pwm pins is not a good idea in my experience...

[@MickyThunderV]

does the quality get worse if the two walkie talkies are too close to each other?

[@cxmmax4265]

why not do like your class d amp with the comparator to go a 1 or 0 logic level for send data and on the reciver part build a h bridge (with death time controller for power consumption) and a lc filter ?

[@rubenponce1011]

does anyone have a comprehensive parts list i can use and a website i can most the parts from?

[@karlyt]

Would it be better to use an STM32/"Blue Pill" for this?

[@whc2001]

Why LM358 when there are many op-amps specially designed for audio (like 5532)?