Gravity NO2 Sensor not working on Raspberry Pi
![userHead](https://dfimg.dfrobot.com/dfPortrait2.png)
Hello,
I am trying to use an Gravity NO2 sensor on my Raspberry Pi Zero W. I followed the instructions here:
https://github.com/DFRobot/DFRobot_MultiGasSensor/tree/main/python/raspberrypi
to no avail. The sensor is connected correctly to the 5V, GND, SDA and SCL pins of the Raspberry Pis GPIO. I can see that it is correct because it is recognized by i2cdetect -y 1 with the i2c address 74. This is also set on the board (SEL = 0, A0 = 0 and A1 = 0) as well as in the example script initiativereport.py (I2C_ADDRESS = 0x74 and I2C_1 = 0x01).
For debugging purposes I also added some print commands to see where the code is while running. I can see that it runs through the setup() section successfully. The problem arises when the script tries to read data. In the “loop()” function, it is not entering the if-statement so no data is plotted into the console. I can leave this running for hours with no change.
Because the sensor is recognized by the RasPi and the Setup of setting the acquire_mode seems to work I wonder where the problem is. Using any Arduino and the recommended library plus one of the example script it works fine. So the sensor is working, the RasPi is working. I suspect a software error somewhere within the functions.
On a side note: When starting the script the first time right after downloading/cloning the github repo, python tells me that it can't find “logging”. It is not imported within DFRobot_MultiGasSensor.py. When I add import logging this error goes away. Might this have something to do with the problem? That pythons own logging library is not working in this case and instead a different one is supposed to be used?
Hi,
I just tested it on a Raspberry Pi 3 and a complete fresh install on a Raspberry Pi 4, but have always the same outcome. The setup (gas.change_acquire_mode) works and then I don't get any data cause it is not entering the if-statement. There has to be some flaw with the code, I can't find another explanation.
![userHeadPic](https://dfimg.dfrobot.com/dfPortrait2.png)
Hi! We have modified the library so you can use the latest Raspberry Pi code. It is recommended to install the logging library. (The library used in the picture is python3)
![](https://dfimg.dfrobot.com/nobody/makelog/bf4cc35cb853c7365b8112dda2dc1932.png)
Hi! We only tested on RaspberryPi4 and it works. Sorry, we have not tested with other versions of Raspberry Pi.
![userHeadPic](https://dfimg.dfrobot.com/dfPortrait2.png)