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Software I2C test

The Funky v2 is so small in size, that only few pins are available on the side header. This is because its main purpose is to interface with one, at most couple sensors while running on battery. The hardware TWI/I2C pins are not available on the side header, but that doesn’t cause much trouble as we can easily do software I2C. This protocol is used in many  devices like RTC, EEPROMs and sensors, so I thought it would be nice to try out. I only have a DS1803 I2C digipot to try out, so I quickly wired it. The SDA and SCL lines require a 4.7K pull-up resistors to the 3.3V line. I used William Greiman’s software I2C library, that allows using any two pins.

So 5 minutes later I was happily talking to the DS1803 digipot and sliding the resistance. To visualize that, I attached a LED:



My code is on Github.

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