How do I wire up the si7021 sensor to an esp32 with oled?

#1

I have an si7021 sensor connected to the esp32w/OLED.
The si7021 has CL, DA, +(3.3), and - (gnd).

I connected the GND to GND, the 3.3 to 3.3, the CL to 22 (this might be wrong?), and the DA to 23.
https://learn.sparkfun.com/tutorials/si7021-humidity-and-temperature-sensor-hookup-guide

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#2

Any free GPIO pins will be fine. Refer to this example can try to scan your device via I2C1:

#3

Thank you for this. I got this to work, but for future reference which pins are ok for SDA and CLK when I read a pinout chart of a chip? I also read that the Si7021 can only be used one at a time on a project because they are ?hardcoded? addresses?

c) You can only have one of these on a given I2C string. This is due to the address being hardcoded (0x40) into the chip. Not Sparkfun’s fault!

#4

If you want to use more than one sensor just use a TCA9548A. That is a 1 to 8 i2c switch.
You can switch between 8 i2c Interfaces to use up to 8 devices with the same address

#5

This keeps finding i2c @ 0x3c even when the i2c doesn’t have power. Readings are all over the board…I have it connected on GND,3.3,PIN22 and PIN21. https://imgur.com/a/jKlpI6d