I’m trying to do a simple LED strip controlled by an ESP32 that receive data through a MQTT protocol. My circuit works for a few time and then it’s unusable, I burnt 2 ESP32 devkit but I don’t understand why. I’m new to electronics and only know the basics I learnt in middle school, so I surely have done something wrong. I use a 12V-5A power supply to power the whole thing. The power supply is linked to the LED strip (a 120 LED long strip), and to a DC-DC tweakable converter that outputs 5V (just a bit less like between 5V and 4.9V) when powered with my 12V power supply. The output is directly pluged into the 5V and the GND pin. Another wire links the Data pin of the LED with a pin of the ESP32. The negative Input and Output of my converter are not isolated so the LED strip has the same ground as the ESP.
Well first of all the ESP32 is a 3.3v device, so you will need to boost the logic level that controls the ledstrip data to 5v, but that is clearly not the issue that should be dealt with first.
Again, even if you supply a bit over 5v to the ESP32 5v pin this will not cause any issues, since there is a lineair regulator onboard to reduce the incoming 5v to 3.3v for the processor.
So are you sure you have connected it to the correct pin ?
@jim-p no I didn’t used USB at the same time as the buck, I did it on a previous card and even though it didn’t kill the card, I read somewhere that it was not really safe
The brown taped wires were plugged on the white connector on the left where I plug the LED strip (there are female connectors under the tape, I taped them to be sure they won’t short). My soldering isn’t that great, but all of the small wires of the top black wire were in the hole before I tried to remove the buck from the case (which I didn’t succeed to remove as you can see)
Well I'm not a fan of those bucks with that little pot on them. The outputs are not always stable.
Connecting the 12V to the buck while the ESP is connected is not a good idea, the output could overshoot 5V before it stabilizes. I would include an on/off switch to disconnect the ESP while you make the 12V connection.
Good solder connections are essential for reliable operation.
I understand, I can’t ensure that those wires didn’t short something (especially the C1 capacitor next to it) there is nothing exposed under the buck. But since it worked a bit before it stopped, could there be any other reason explaining why it stopped working ? (I don’t want to kill my last ESP if something else is not correct )
By the way, if you have any suggestion or reference on how to do better soldering, I’m all ears
That's how it goes. Component's can tollerate abuse for a while, bad solder joints can make contact/non-contact when temperature raises etc...
I agree with jim-p for that buck, also your voltage measurements can be off little bit. Voltage regulator of that C6 has absolute max 7V, much lower than many other Esp32 boards.
Get NON-lead-free solder with flux core and practice. Cut all the excess wire away and inspect every solder joint. If your solder is a "ball", it's bad. Correct joint has a form of cone.
Which part of that ? What is the type of 3.3v regulator on the board actually, does anyone know ? Usually they can take a bit more than 5v and all other parts i suspect (hmmm..) are 3.3v devices / parts
@jim-p I saw your answer but as I said in post #6 I didn’t do that with the ESP on the picture, I did it with another ESP. The one the picture wasn’t connected through USB and 12V at the same time.
@ZX80 the power supply is a GST60A12-P1J from MeanWell.
Does anything get hot ?
If you’re asking for the power supply, the answer is no. If it’s for the ESP, yes the ESP chip is really hot (I almost burnt my finger on it) so I supposed it’s definitly dead.
I’m not sure to understand your third question, if I disconnect the led strip I have no feed back, just the chip turning really hot (there is no LED that lights up on the ESP when it is powered up, even when the ESP wasn’t dead). When I plug the 12V power supply nothing happens but If I plug it with USB there is a buzzy noise (I think that’s the noise of a dead USB controller)
As far as I understand from all of your answers this circuit should work fine with better soldering and a better buck or an ESP that can deal with a higher voltage fluctuation if the buck sometimes doesn’t outputs what it should? Is there any security I could add before the 5V pin to protect the ESP from overvoltage?
Oh ok! Sorry, I totally misunderstood what you said in that post. Adding a switch should be fine! Can this overshoot damages the ESP just enough to make it works for a bit before it stops working? In my case, the ESP stopped working a while after being powered up. I can’t say when exactly, but it worked for 5 minutes at least. The LEDs were on for a couple of hours. I didn’t sent any request through MQTT during this time so I have no info about when it stopped.
Yes it's possible but It's more likely that the output of that buck is not stable. The output is set by the pot. Those cheap tiny pots may not maintain it's setting over time. If the setting changes the output voltage changes.
Just to cover all the bases, what type of LED string are you using?
