I’ve installed a bme280 sensor. It functioned very well but after a power cycle the sensor refuses to send measurements. It is seen at i2c adres, communication is active, but no readings. Sometimes it starts output at sudden time, but it stays a sleep most of the time.
Sensor is working well, till device reboots. Esp32 enables pull-up resistance as i2c is configured. I have a BH1750 light sensor on the same wire and that works as a Sharm.
As the device can come up again (can’t reproduce why) it works till the next reboot or power failure.
btw the sensor is up on reboot as i2c detects it…
[12:35:11][I][i2c:033]: Scanning i2c bus for active devices...
[12:35:11][I][i2c:040]: Found i2c device at address 0x23
[12:35:11][I][i2c:040]: Found i2c device at address 0x76
This is the exact behavior I experienced as well. Adding the External Pull-Up resistors resolved the poor reboot behavior I experienced with some I2C devices.
Thank you Vinden, that fixed the problem for me aswell. I found a website that explained why the sensors didn’t work if you bind them together on one wire and are powered with 5v.
I installed a 10k PullUp resistor and bam all works as a Sharm. The strange behavior was that the light sensor on the same wire was working and the BME280 wasn’t. But this fixed the problem.