ofxTrill

This is a convenience wrapper for the Trill family of sensors from Bela (https://bela.io/products/trill/)

It is intended for use with the Raspberry Pi GPIO interface and is based on the Trill-Linux repository (the contents of which are in the libs folder here).

Setup

Enable the i2c interface via raspi-config. SDA and SCL connect to GPIO 2 and 3 respectively. Connect GND to ground and VCC to 3.3v (Pin 1 - top left if your board is oriented with the USB port facing down).

To test install i2c-tools:

sudo apt-get install i2c-tools -y
sudo i2cdetect -y 1

You should see something like:

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- 20 -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

The values are:

• 20: Bar
• 28: Square
• 30: Craft
• 38: Ring
• 40: Hex
• 42: Flex

Test your sensor and check that your values match your model. For more information about the sensors and how to chain multiple sensors together read the official documentation: https://learn.bela.io/using-trill/get-started-with-trill/

Why?

ADCs are awkward to deal with and affordable low latency input devices that use minimal pins and allowed for discrete values sounded useful to me.