Rpi HQ (IMX477) sensor temperature ?

[PsY4]

I think I've tried everything... I can't get my Rpi HQ (IMX477) camera to report its sensor temperature... so can't work with darks...

Fresh install, Linux 6.12.60-v8 so the IMX477 register kernel fix is here.

Allsky v2024.12.06_06, so sensor temperature reporting is here...

Manually reading metdata using rpicam-still -o test.jpg --metadata md.json also returns -20°c ...

{
    "ExposureTime": 66654,
    "ColourGains": [ 2.510905, 1.656681 ],
    "SensorTimestamp": 1630536801000,
    "FrameWallClock": 1765034729291651840,
    "ColourTemperature": 4000,
    "ScalerCrop": "(0, 0)/4056x3040",
    "ColourCorrectionMatrix": [ 2.085834, -0.879262, -0.206567, -0.386221, 2.048327, -0.662106, -0.095295, -0.581929, 1.677223 ],
    "FocusFoM": 1574,
    "SensorBlackLevels": [ 4096, 4096, 4096, 4096 ],
    "DigitalGain": 1.006058,
    "AeState": 1,
    "SensorTemperature": -20.000000,
    "Lux": 0.157450,
    "FrameDuration": 85335,
    "AnalogueGain": 7.876923
}

What's driving me crazy is I can see many Allsky users on the map, with the same camera, reporting sensor temp on their overlay...
(ie : https://dragon.me.uk/allsky/ , http://harkbroek.nl/allsky/ )

How do you guys have managed to get it ?

[Alex-developer]

What OS are you running?

I have just tried on Pi OS (Trixie) And the latest kernel I can get is6.12.47+rpt-rpi-v8

Testing on this the camera always seem to return 20C !!!

{
    "ExposureTime": 66657,
    "ColourGains": [ 2.026269, 2.423779 ],
    "SensorTimestamp": 114783133000,
    "FrameWallClock": 1765044265245873664,
    "ColourTemperature": 2881,
    "ScalerCrop": "(0, 0)/4056x3040",
    "ColourCorrectionMatrix": [ 2.019514, -0.772632, -0.246892, -0.418861, 2.044070, -0.625209, -0.023769, -0.917453, 1.941225 ],
    "FocusFoM": 25930,
    "SensorBlackLevels": [ 4096, 4096, 4096, 4096 ],
    "DigitalGain": 1.000332,
    "AeState": 1,
    "SensorTemperature": 20.000000,
    "Lux": 24.636351,
    "FrameDuration": 100000,
    "AnalogueGain": 6.692811
}```

[PsY4]

I installed Pi OS Lite from the Raspberry Pi Imager

I'll try other versions, and get back to you...

[PsY4]

I updated the imager and got a new Pi OS version : 6.12.47+rpt-rpi-v8 like yours
But still no luck, mine always returns -20°c

I've read somewhere it needs a few frames before sending the actual temperature, but even after 50 frames captured, still -20°c :/

{
    "ExposureTime": 66657,
    "ColourGains": [ 2.510905, 1.656681 ],
    "SensorTimestamp": 650796686000,
    "FrameWallClock": 1765092098773495296,
    "ColourTemperature": 4000,
    "ScalerCrop": "(0, 0)/4056x3040",
    "ColourCorrectionMatrix": [ 2.085834, -0.879262, -0.206567, -0.386221, 2.048327, -0.662106, -0.095295, -0
.581929, 1.677223 ],
    "FocusFoM": 1546,
    "SensorBlackLevels": [ 4096, 4096, 4096, 4096 ],
    "DigitalGain": 1.005231,
    "AeState": 1,
    "SensorTemperature": -20.000000,
    "Lux": 0.151673,
    "FrameDuration": 100000,
    "AnalogueGain": 7.876923
}

That's already weird you have a positive 20°c and I get a negative -20°c ...

[Alex-developer]

I updated the imager and got a new Pi OS version : 6.12.47+rpt-rpi-v8 like yours But still no luck, mine always returns -20°c

I've read somewhere it needs a few frames before sending the actual temperature, but even after 50 frames captured, still -20°c :/

{
    "ExposureTime": 66657,
    "ColourGains": [ 2.510905, 1.656681 ],
    "SensorTimestamp": 650796686000,
    "FrameWallClock": 1765092098773495296,
    "ColourTemperature": 4000,
    "ScalerCrop": "(0, 0)/4056x3040",
    "ColourCorrectionMatrix": [ 2.085834, -0.879262, -0.206567, -0.386221, 2.048327, -0.662106, -0.095295, -0
.581929, 1.677223 ],
    "FocusFoM": 1546,
    "SensorBlackLevels": [ 4096, 4096, 4096, 4096 ],
    "DigitalGain": 1.005231,
    "AeState": 1,
    "SensorTemperature": -20.000000,
    "Lux": 0.151673,
    "FrameDuration": 100000,
    "AnalogueGain": 7.876923
}

That's already weird you have a positive 20°c and I get a negative -20°c ...

I agree it's odd. It might be a better to ask the question on the camera apps GitHub