Arduino Forum

Using Arduino => Sensors => Topic started by: hopsandjumps on Apr 19, 2019, 05:50 pm

Title: DHT22 sensor cutting out - EMF fix
Post by: hopsandjumps on Apr 19, 2019, 05:50 pm
Hi All,

I'm working on building in incubator. I have two arduino uno's, one for temperature and one for humidity. I piezoelectric fogger is used to generate humidity. My control loops are working fine, I just have one problem with the system.

I have a DHT22 for humidity control. I can ready a stable humidity, when the piezoelectric humidifier is turned on, the humidity reading is fine. But when its turns off, the DHT22 dies untill the VCC pin is reset. The relays are solid state, they should not create a magnetic field.

I think its back emf. Have you guys any advice on how to apply a flywheel diode to my circuit?

One other thing that points to EMF. The system has another arduino board to control temperature, when the humidifier is turned on, the temperature signal starts to get noisy.

Regards,

John