Add support for generic linux drivers for various sensors (I2C, IIO/sysfs, ...)

[geoffrey-vl]

Hi,

Context: I'm using a RPI libcamera based CCD, with a Sony IMX462 sensor. The sensor itself lacks an on-die temp sensor. So I added a HTU21D temp/humidity sensor to my Pi's housing, close to the CCD, to get a rough idea. I'm using a custom linux driver and service to use the HTU21D sensor for monitoring.

Now, I wonder if we could somehow add support in INDI to use the sensor. I could add a very specific HTU21D driver, but then again maybe it's better to allow the driver to be support various linux based environment sensors in the future. I'm not even sure what the base functionality of this driver could be. I wouldn't call it CCD temperature sensor, since not really an internal CCD sensor anyway, although for my use case I wouldn't mind either (and maybe some manufacturers even implement it that way -> I have no idea really). Or any other options I could consider? For example, it would be nice if we could also have a notion of the humidity somehow.

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Did you make sure there is no existing driver for your device? Please check [supported devices portal](https://indilib.org/devices].
Confirms no drivers exist for your device.

Provide link to product page
https://github.com/geoffrey-vl/linux-htu21d

Describe device family

• Auxiliary (Anything else that does not fit above).

Provide device communication protocol
All devices use some sort of communication language between them and the host system. This could be called Command Set or SDK. It is best to provide a link to a document or PDF with such details from the manufacutrer. It needs to include the following information:

• Communication Method: I2C
• Communication Protocol: Custom I2C registers

Hardware Sample
No

[knro]

This would be a simple INDI::Weather driver that only reports temperature and can probably be added to INDI core (not 3rd party). You can use the INDI I2C Connection Plugin to communicate with your device. So in short:

1. Create I2C Temperature Sensor Driver derived from INDI::Weather
2. Use the connection plugin

Extra points for making it generic to cover more than a specific model. Maybe a parameter to specify register..etc.

[knro]

@geoffrey-vl Do you have any questions or clarifications?

[geoffrey-vl]

No, not at this moment, I haven't looked into it further for now but maybe somewhere soon. I'll close this one for now