Issues on power supply (ESP32, PCB)

[prettyflacko]

Hello everyone,

I have an issue with my power supply/ battery management.

As you can see in the schematics I attached, I have an SDS011 connected to an ESP32 and is taking power from a step up converter that has at his heart a ME2108
that can hold max 600mA load. Thing is that ESP32 has huge spikes in current draw when I activate WIFI. This issue is non existent if I disconnect the SDS011.

So by activating WIFI + SDS011 the voltage drops in like 2-5 seconds from 5V to 0.60V. I did some debugging on the board and it seems it happens before 5V booster.

Therefore I think the issue is coming from the battery management circuit, now I have no idea how to debug further so a helping hand/mind will be much appreciated.

[kgray9]

Hi @prettyflacko

Nice schematic. Do you know how much power the SDS011 uses?

Does the voltage stay at 0.60V? If it just drops for a moment, try adding a large capacitor from 5V to GND.

[prettyflacko]

Thanks!

SDS011 uses 100mA and with the ESP32 connected I get ~500mA spikes.

The first thing that I did was to add a cap to the 5V out&in and is still trips out. I use a 16V cap with 220uF

[kgray9]

It seems as if "BATT-OUT" isn't connected to the DW1A. Im not sure if that would cause the problem.

Here is a schematic I have. Ignore the ESP-12 part.

The lower part is not completed / correct. I searched for the tp4056 circuit though and copied it exactly from a reliable source.

[prettyflacko]

@kgray9

Is the circuit working fine for you with the above setup? I would like to inspire from you if it does. I see some small differences.

For the current battery circuit I inspired myself from here: https://www.best-microcontroller-projects.com/tp4056.html

[kgray9]

PCBs are so expensive, I only have printed 1 out of every 10 I make. I haven't ordered this one so this schematic is untested.

In your link, the schematic also has the connection between "BATT-OUT" and the DW1A. I made it bold below on the schematic from your link.

[prettyflacko]

Hmm I missed that one. I did added now and is still trips the voltage/ collapses.

[kgray9]

When exactly does the voltage drop? Does it drop when the ESP32 use WiFi? Or only when the SDS011 is turned on?

Where exactly are you measuring the voltage?

Does any of the circuit work at all? Such as the SDS011, or ESP32?

[prettyflacko]

Everything works except when I connect SDS011 and run it with the rest of the circuit. I measured before the 5V booster and when the voltage collapses (is random sometimes in 1 min sometimes at start-up) I can see that what comes out of battery circuit is 0.60V. So the issue is there somehow.

[kgray9]

Are you measuring from this pad?

Try disconnecting the battery, and the usb, and power the circuit with 5V on that pad; just to try and narrow it down.