ESP32 Forum

Im making a music player. I use the batch burn board, so that i can program the bare esp32 chip. I finished the music player, and tested it through the board, it works well. I soldered everingthing to the bare board now, added a lipo battery and switch, and no sound comes out. Strangely enough, if i push it into the batch board while on (it cant fit in all the way with the wires soldered), it works, and I can hear the audio, even though the board is only running from the battery, and the power switch is off on the board (switch is on for the esp). Is there a connection that needs to be briged or something? I'm curious why it wont work without the board

Pretty hard to say without any schematics or pictures.

Well, i have the esp32 wired to an sd card reader, a battery, and a piezo speaker. The battery is also connected to a switch, and lipo charger, my multimeter said it gave around 3.7v iirc. The vcc of the esp and sdcard reader are connected, as well as the ground for the sd card reader, esp, and the speaker (other end is on io4 which is pwm currently, got that to work at a good quality). If needed i can try to post a picture, but its a pretty basic setup

EDIT: To clarify a little more, the ESP32, SD card reader, Battery and Lipo charger are all wired in paralell. The on/off switch is wired to the vcc line, separating the battery+charger from the esp+sdcard reader.

What instructions or recipe did you follow to build the board? Do you have a schematic diagram of the circuit you have assembled? Can you post a photo of the board?

Also, you're running your ESP32 chip directly from a LiIon? Please do understand that a charged LiIon can be up to 4.2V, which will damage the ESP32.

My wiring is messy, but this is currently the setup I have

I'm aware the higher voltage could damage the ESP32, but I want to test that it works with this setup. I tried a voltage divider with a 100k resistor and a 470k resistor, which should have put it in a safe range, although my multimeter was getting less than 1 volt from that. (I had the 100k connect the VCC to the battery, and the 470k connect the ground to the battery when I tested that).

Okay, so you're using an Wrover32 module and not a bare chip, as you mention in the title? Also, never use a voltage divider to get a lower power supply voltage, especially not with values that insanely high as that. Instead, use a nice 3.3V LDO or something. Or grab something like an ESP32 Thing board, which has all the logic for LiIon stuff integrated. If any, in the current setup you're running the ESP32 out of spec, and we can't guarantee anything then: the chip may not blow up instantly, but it is very well possible it'll have boot problems. So get your power supply in order first, then we can continue debugging.

The chip is a esp32-wroom (not sure if it makes a difference). Ill look into a ldo with a dropout of around 0.4v, so it will be well within the 2.6-3.6v range

I got a voltage adjuster (one with the screw to adjust output). Because of the dropout, i swapped the charger for one from a portable power bank, so it outputs 5v, which the adjuster outputs about 3.2v to the rest of the circuit now, although im still not getting sound output

Edit: not sure what i did, but its working great now. Just need to 3d print a shell

Please, can you tell me if connecting GND and 3V3 of an wroom-32 is sufficient to trigger a boot? (I know, sounds stupid if the answer is yes, but I'm not an expert in soldering so it's kinda tough to decipher what's wrong...).