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DHT22 - one pullup for more then one DHT22?

Posted: Wed Apr 26, 2017 11:36 am
by warhammer73
Hello,

I will use 3 DHT22 with my rasperry. For testing I'm using one 10k pullup resistor for each DHT22.
For the final implementation: Can I use just one resistor for all 3 DHT22?


Thanks!

Re: DHT22 - one pullup for more then one DHT22?

Posted: Wed Apr 26, 2017 12:20 pm
by PhilE
Moved where it is more likely to be answered.

Re: DHT22 - one pullup for more then one DHT22?

Posted: Wed Apr 26, 2017 12:24 pm
by PhilE
BTW, I've never seen or used a DHT22 but from what I've just googled it uses a simpler protocol than Onewire (there's no concept of an address) and requires a dedicated line for each device, and you can't pull up multiple wires with a single resistor without shorting them together.

Re: DHT22 - one pullup for more then one DHT22?

Posted: Wed Apr 26, 2017 12:39 pm
by warhammer73
You are right.
With my ideal I will connect all data Pins together...

Re: DHT22 - one pullup for more then one DHT22?

Posted: Wed Apr 26, 2017 1:19 pm
by joan
Each DHT22 needs a separate GPIO and a separate resistor.

Re: DHT22 - one pullup for more then one DHT22?

Posted: Wed Apr 26, 2017 1:37 pm
by warhammer73
Thanks!