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Using I2C sensors on a linux via a USB and IIO

A short story of getting a tiny, cheap USB I²C adapter for a home server, learning about the Industrial I/O linux subsystem, and connecting it to collectd.

A few months ago I wrote about using a Raspberry Pi with some I²C sensors to collect data for Collectd1. While it worked well, it made me realise that having the RPi running a full fledged operating system means I need to apply security patches to yet another machine, and that is not something I want to deal with. I also have a former laptop, running as a ZFS based NAS, so why not use that?

After venturing into a fruitless dig to use the I²C port in the VGA connector2 I verified that indeed, as concluded in the tutorial, it doesn’t work with embedded Intel graphics on linux.

Alternative I started looking at USB I²C adapter, but they are expensive. There is one project though, which looked very promising, and it didn’t require a full-fledged Arduino either: Till Harbaum’s I²C-Tiny-USB3.”

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