ESP Soil Moisture Sensor Rev 2.1 TMP112 I2C connections



Shouldn’t there be pull-up resistors on GPIO4 and GPIO5 for the I2C connection to the TMP112 temperature sensor? I’m finding I2C communication unreliable, but when I add pull-up resistors, it’s fine.

I was also wondering if the schematic here is correct:

It looks like the connections to GPIO4 and GPIO5 on the ESP12 are swapped?




I checked the i2c source code. There’s internal PULLUP already. We also tested the original sketch for sensor. It works fine. Could you please show the sketch you tested?

The schematic place an old ESP-12 module. That’s a little difference with ESP-12F. The GPIO4 and GPIO5 are swapped. But in fact, we use ESP-12F with the sensor. We’ll replace the module in the schematic. Thank you very much for mention about this.


Thanks for your reply. I’m using micropython, which I don’t think provides the ability to activate internal pullups. I’ll add some externally in the mean time.


Seems there’s no PULLUP in MicroPython’s I2C driver.