Please add MCP9808 sensor support to i2c-sensor dtoverlay list

[Jibun-no-Kage]

Describe the bug

Not a bug but a support request. Please add MCP9808 sensor support to i2c-sensor dtoverlay list. As I understand it, this sensor already is supported by the Linux kernel? Thanks.

Steps to reproduce the behaviour

NA

Device (s)

Other

System

Latest Raspberry Pi firmware image (or so I believe what is how support is implemented).

Logs

No response

Additional context

Just a suggestion but maybe setup a sub section on github under the Raspberry Pi area for such requests?

[pelwell]

Done - see ac4cf1b.

GitHub doesn't allow the creation of arbitrary sections, and requesting additions via the Issues page works for us.

[Jibun-no-Kage]

Cool, I just did not want to post the requests the wrong way or such. I should be able to test MCP9808 sensor first thing tomorrow, once I get the update.

[Jibun-no-Kage]

Is this update published yet? Ran rpi-update on a Pi4, then added dtoverlay=i2c-sensor,mcp980x,addr=0x18 to /boot/config.txt, and rebooted, but did not see the typical UU on i2c-detect -y 1 scan? Shows 18 as address rather than UU.

[pelwell]

Not yet - the last update was on Monday. You can see the release history here: https://github.com/raspberrypi/rpi-firmware/commits/master

[Jibun-no-Kage]

Excellent, that is going to be a book mark! Thanks.

[popcornmix]

rpi-update contains this now.

[Jibun-no-Kage]

Excellent! Yup, now see kernel/dtoverlay control of the sensor, i.e. UU in i2c address slot (0x18) in the i2c detect result.

[Jibun-no-Kage]

Odd... the direct query of temp1_input under kernel/dtoverlay... the result is '62' which does not make sense. So I pulled the sample test script from Adafruit, and after loading the dependencies, and running the simple test, the results were as expected.

# cd /root
# apt install build-essential python3-dev python3-pip python3-smbus git
# pip3 install RPi.GPIO
# git clone https://github.com/adafruit/Adafruit_Python_MCP9808.git
# cd Adafruit_Python_MCP9808
# python3 setup.py install

# cd examples
# python3 simpletest.py
Temperature: 27.250C / 81.050F
Temperature: 27.312C / 81.162F
Temperature: 27.312C / 81.162F
Temperature: 27.250C / 81.050F

The dtoverlay just provides visibility to the native kernel support, right? Thus, I am not sure this is Raspberry Pi issue to solve, but documented here to illustrate there seems to be an issue with the existing kernel support for MCP9808 sensor.