Arduino UNO + esp8266 shield, how many DHT11 can be added?
Each DHT needs a dedicated digital pin. Some digital pins are used for other tasks, but it depends if you’re worried about the occasional random temp/humidity reading at boot-up.
If you run out of pins then you could go to a Mega or multiplexor.
However, it’s not necessarily a very logical approach to have all of your sensors wired back to one Uno. Depending on what you’re trying to achieve, you may be better having single sensors connected to ESP8266/NodeMCU’s (without the Uno).
There is apparently a theoretical limit of 20m of wire from the DHT to the MPU, but it depends on the environment as to whether that’s actually achievable with multiple devices. It certainly may not be desirable.
Also the DHT11 is crappiest sensor you could choose. The DHT22 is slightly better, but I’d go for the BME280, every time. This also gives you alternative options about which wiring topography and communication protocol to use.
Pete.
1 Like
Arduino uno + esp8266
3 DHT11 sensor connection codes
note: on the same card.
Arduino uno + esp8266
3 piece DHT11 sensor connection codes
note: on the same card.
you could also get ESP32 for around 5$
What is your question?
Pete.