ESP32 Forum

Hi all,

I am working on a project that will combine an ESP32 devkit rev 1 and a DS3231 module like this one.

I would appreciate it if you could comment on my current thinking w.r.t pull-up resistors for the I2C SDA & SCL lines:
- the Wire library will enable the internal pullups on the ESP32, that's about 10K
- the module itself has additional 10K pullups on each line (I'll check once I receive it)
- I will add an additional 10k pull-up per line

This should result in 3.3K pull-ups per line, which should work well for that bus (3.3V, single I2C device, short lines).

Any thoughts?
Thanks!
Franck

Internals are not 10k, they're about 50k.
That still leaves you with <5k, which will be fine. If you have any issues you can always lower the I2C speed.

Thanks for the feedback!

Franck