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DHT22 sensor data pin reading low

Hi Team Nordic,

According to the AM2302 (DHT22) datasheet, the data pin will be pulled to high state in idle state. But in my case, when i am reading the data pin before even sending any signal to the sensor, i am reading 0 on the data pin. I am using p0.07 (pin 9 ) as data pin. VCC -> 5V, GND -> GND.

Am i not reading the pin correctly or is it a communication protocol error that i have to figure out?

Please find attached the image with output. 

Thanks, 

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  • Hi,

    I do not have any experience with the DHT22, but I noticed that it needs a supply voltage of minimum 3.3 V. Which supply voltage do you use?

    It looks like you are reading the pin correctly (you cannot really go wrong with nrf_gpio_pin_read() as all it does is read the state of the pin). Have you looked at the signal on the pin using an oscilloscope? That way you would know what signal is actually there.

Reply
  • Hi,

    I do not have any experience with the DHT22, but I noticed that it needs a supply voltage of minimum 3.3 V. Which supply voltage do you use?

    It looks like you are reading the pin correctly (you cannot really go wrong with nrf_gpio_pin_read() as all it does is read the state of the pin). Have you looked at the signal on the pin using an oscilloscope? That way you would know what signal is actually there.

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