Trouble powering ESP32 using Raspberry Pi

[FaithRaven]

I'm trying to power my HUZZAH32 by connecting it to a Raspberry Pi 4 USB port. It's the only connected device, other the Raspberry Pi fan that's tied to a 3v pin. I'd like to do this just so I avoid having yet another power prick laying around.

My ESP 32 board works perfectly fine when powered by a 5V 1A power bank or by my PC USB. But it doesn't seem to get enough juice from the Pi, even though the Pi is supposed to offer 1.2A. I have the same issue with a Raspberry Pi 3b as well.

Am I missing something?

[username]

I have noticed that some board do not boot up until the comport is opened. Have you opened a terminal on the PI to your HUZZAH32 ?

[FaithRaven]

The board works just fine when it's not using much power. I have a BME680 connected to it that saves it's state into RTC. There's also a LED that's usually off. All works fine at this point. But when the LED is turned on, `gpio_deep_sleep_hold_en()` is called and the board goes into deep sleep for ~5 minutes. It never wakes up again. If the LED isn't turned on and `gpio_deep_sleep_hold_en()` is not called, everything continues to work just fine and the board successfully wakes up from deep sleep.

I seriously doubt that there's a problem with my ESP32 or its setup because it works perfectly fine when connected to the PC or a 1A power bank. I don't think there's much wrong with the Pi either, because I get the very same behavior on another Pi, 3b.

[ESP_Angus]

The board works just fine when it's not using much power. I have a BME680 connected to it that saves it's state into RTC. There's also a LED that's usually off. All works fine at this point. But when the LED is turned on, `gpio_deep_sleep_hold_en()` is called and the board goes into deep sleep for ~5 minutes. It never wakes up again. If the LED isn't turned on and `gpio_deep_sleep_hold_en()` is not called, everything continues to work just fine and the board successfully wakes up from deep sleep.

So the ESP32 actually works fine connected to the Raspberry Pi USB port, except in this one specific situation? And that situation works fine when powered via other methods? That's very strange.

Is anything apart from the LED and the BME680 connected to the HUZZAH32? Which pin(s) are in use?

[FaithRaven]

Is anything apart from the LED and the BME680 connected to the HUZZAH32? Which pin(s) are in use?

There's nothing else. The BME680 is connected via SCL/SDA, the LED via A1 (GPIO #25).

Actually it's not only that one specific situation. When, on another HUZZAH32 board, I try to write to an SD card using Adafruit's MicroSD breakout board connected via SPI it fails when powered by the Pi but works when powered by something else. There's no GPIO hold involved in this case. The SD card breakout has a led that lights up when the card is in use. When connected to the Pi it brightens only to about half the intensity it brightens when powered by something else.

So it feels quite obvious that the ESP32 is not getting enough current from the Pi, but it should. Hence my confusion.

[mikemoy]

What are you powering the RPI with?
You should have one of these in your arsenal.
https://www.amazon.com/Eversame-Multime ... NG8203YTK0

[FaithRaven]

I power the RPI 4 with the Official UK Raspberry Pi 4 Power Supply (5.1V 3A). The RPI 3B has an official power supply as well.

[mikemoy]

Do you have a volt meter that you can measure the 5v on the HUZZAH32 regulator

[FaithRaven]

I do, but you'll have to tell me where to measure

[markkuk]

You should see 5V between the GND and USB pins, and 3.3V between GND and 3V