ESP32 Forum

I don't know if this is the right forum, but I have a circuit connected to a Saola board (ESP32-S2-ROVER) and I had no ability to connect via softAP. After much testing with code changes, I noted that the unit appeared to be starting the softAP just fine (returns an IP address as well as the WiFi.softAP() method returns true for my call). So, I thought there may be a unintended disable through the IO lines and started to remove some of my connections. I got down to 2, a power supply rail connected to the 5V IO pin and a ground connected to the GND. When either of these are connected to my associated circuit, the WiFi is no longer available (disappears from my selection on a 2 phone devices). After removing either connection there is still no WiFi ssid available (or network) BUT with a reset, it becomes available. I tried this with both of the GND ports (next to the 5V AND next to the RST IO pins) and the same behavior. Does anyone know why I might lose the WiFi when I power a circuit (from a USB connection)? I realize that knowing the circuit would be helpful, but it is a little complicated. I am not sure how easy it will be to check power draw for the circuit (in case the circuit is drawing too much power and the radio is not able to transmit a signal), but I will try to figure out a way to troubleshoot. I may try to power through external for my connected circuit and see if it transmits, then, but besides a potential power issue, anyone have any ideas why else I might lose radio TX?
As a note the resistance in the circuit (between the 5V rail and the ground) is measured to be ~3MOhm, so in theory I would estimate a 1.7uA draw with 8.3uW (VERY roughly), which doesn't seem like much power draw away from the radio. There are several active components and that value seems to greatly underestimate the power draw. I will attempt outside power and see if that allows the radio to function properly.

I would suspect a power supply issue, because you said with the aux circuit disconnected from 5V it works, aux circuit connected it doesn't work. Using WiFi is a big current spike, it can cause brownout detection and your ESP32 will keep rebooting in a loop.

Measure the active current draw from your other circuit being powered from the 5V rail. Not just the resistance from 5V to GND, but what the actual components are drawing. If it's a few hundred mA you could easily be in the ballpark where that active circuit, plus the wifi current draw, is too much for your usb supply.