02-14-2025, 09:35 AM
I thought perhaps the problem might be conflicting pullups, the DHT22 module has a 10k pullup to Vcc which is 5V when powered from the 433MHz connector and the board has a 47k pullup to 3V on the GPIO connector then this would cause problems. I moved the Vcc for the DHT22 module across to the 3V line on the GPIO connector and I'm still getting the same results, temperature is accurate, currently 24.2 in DHT11 mode which shouldn't be able to sense fractional degrees, humidity is stuck on 2%.
In any case it seems unsafe to power a DHT22 module with internal pullups, which many have, from the 5V 433Mhz connector because you've got pullups to both 3V and 5V, and you're connecting the 3V to 5V line via a 10k + 47k resistor. According to the circuit diagram this goes straight to the ESP32 pin 8 (labelled HT1) which is 2.3 - 3.6V and presumably can't handle 5V.
In any case it seems unsafe to power a DHT22 module with internal pullups, which many have, from the 5V 433Mhz connector because you've got pullups to both 3V and 5V, and you're connecting the 3V to 5V line via a 10k + 47k resistor. According to the circuit diagram this goes straight to the ESP32 pin 8 (labelled HT1) which is 2.3 - 3.6V and presumably can't handle 5V.