Esp can't boot when sensor attached !?

[Cagire]

Hello,

Trying to set up a heating system controller based on esp32. I had a couple of temperature 1 wire sensors ds18b20 mounted with 4.7k pullup resistor and it was working fine on the test setup. Now I moved one of the sensor at the end of a 25m twisted pairs cable, with a 2.2k pullup resistor. I also pinned this particular sensor to a dedicated GPIO (27).

The sensor is working fine when I plug the resistor after esp32 boot sequence is completed. However, if I try to boot / reset the esp when resistor is wired, it doesn't work.

I tried an another usb power supply, a 5v 2a power supply , changed gpio ... Nothing.

Thank you for helping

[Sprite]

Can you clarify 'it doesn't work', e.g. what output do you see on the serial port?

[Cagire]

Ok so I managed to plug a laptop on the device in order to have a look at the serial port outputs, and the issue is related to wifi connection. It's booting, but cannot connect the wifi.

Code: Select all

[W][wifi_esp32:494]: Event: Disconnected ssid='Tusseau_koala' bssid=[redacted] reason='Auth Expired'
[W][wifi:549]: Error while connecting to network.

As soon as I disconnect the pullup reistor and press reset, it's booting and connect perfectly at first attempt.

Thank you

[Cagire]

Problem solved, it was a power issue as I suspected. I transfered all my sensors to +3.3V instead of +5v and now my ESP can boot and connect the wifi with all stuff plugged.