Two DHT22 sensors with nodemcu (v2) and blynk app via wifi

PeteKnight · August 26, 2021, 3:32pm

PeteKnight:

I’d suggest that you go back to your original code, remove the delay, change the timer from 1000ms to 10000ms, add-in serial prints for h1, t1, h2 and t2 and change these nan tests to that they are two separate if statements with the correct number of closing brackets…
Grimor_Jander:
> if (isnan(h1) || isnan(t1)) {
    Serial.println("Failed to read from DHT sensor1!");
    if (isnan(h2) || isnan(t2)) {
      Serial.println("Failed to read from DHT sensor2!");
      return;
    }
> ```
I’d also remove the comments that are irrelevant (such as the unused types of DHT sensors, and how to obtain an auth token etc).

You’d have it working now if you’d done this.

Pete.

Grimor_Jander · August 26, 2021, 5:16pm

I’m really sorry I missed that part, Pete.
It is not my intention to reject any help, but I am really new to programming and also the language does not favor the interpretation either.
I just have made your modification and it behaves the same way.
Sensor 1 only gets NAN results if booted connected to serial monitor.
As stand alone it works fine.
I have also tried to alternate the dht22 modules in the breadboard in case it were a defective unit, but the reading number1 continues to fail, so it must not be something hardware related .

Grimor_Jander · August 26, 2021, 5:19pm

The project im trying to make is a “gouldian finch incubator” and not sure if dht22 would be precise enought or sht30 will be a better choice

PeteKnight · August 26, 2021, 5:39pm

The DHT range of sensors are awful. They belong in the bin.

Pete.

Blynk_Coeur · August 26, 2021, 5:46pm

The best choice is AHT10 for $ 2.5, I am using it with my Nextion thermostat project

oxox · August 27, 2021, 7:10am

why this sensor never wear clothes. looks awful

Grimor_Jander · August 29, 2021, 6:22pm

Now I think that also the failures of 1 sensor can be related to lack of power from the usb port. It has become more apparent when introducing a servo to my circuit. I think that is why the failures occurred much more with the serial monitor (usb powered) than with the wall current transformer.

oxox · August 30, 2021, 1:13am

brother. try 3.3V supply i assume your are using DHT22 module instead of sensor alone. 3.3V to supply. direct data to DX. ground to ground. booms magic happens