DHT22 signal drops when 12v fans are triggered
Posted: 17 Mar 2023, 15:52
Hi folks
I'm having an issue which has so far eluded me.
I have an esp32 dev kit module connected to the following:
- 2x DHT22 sensors, measuring temp and humidty in greenhouse and outside. (GPIO 2 and 4)
- 4x float sensors, measure water levels in my water tanks (GPIO 5, 18, 19, 21)
- 1x 4-way relay module, powered from the esp32 5v pin (GPIO 25, 26, 32, 33). The fan is connected to GPIO 32
I then have a 12v fan connected to one of the relays above, with power coming from a separate supply.
Everything works perfectly, except when the fans are triggered through the relay. After the fans have been running for about 2 min, I get "nan" from my DHT22 sensors and it won't recover the readings unless I turn the power to the esp32 off and on again.
I thought maybe the 12v power supply was interfering with the sensor cables and have tried to separate them, but no joy.
Any ideas what else might be causing the issue or do I need to do more to separate the power supply from the sensor cables?
Thanks in advance
ActionAnt
I'm having an issue which has so far eluded me.
I have an esp32 dev kit module connected to the following:
- 2x DHT22 sensors, measuring temp and humidty in greenhouse and outside. (GPIO 2 and 4)
- 4x float sensors, measure water levels in my water tanks (GPIO 5, 18, 19, 21)
- 1x 4-way relay module, powered from the esp32 5v pin (GPIO 25, 26, 32, 33). The fan is connected to GPIO 32
I then have a 12v fan connected to one of the relays above, with power coming from a separate supply.
Everything works perfectly, except when the fans are triggered through the relay. After the fans have been running for about 2 min, I get "nan" from my DHT22 sensors and it won't recover the readings unless I turn the power to the esp32 off and on again.
I thought maybe the 12v power supply was interfering with the sensor cables and have tried to separate them, but no joy.
Any ideas what else might be causing the issue or do I need to do more to separate the power supply from the sensor cables?
Thanks in advance
ActionAnt