ofxAddons
Receives multitouch events over a 9600-baud serial 1-byte protocol from custom input devices such as MPR121-based pads.
README
ofxSerialTouchPad
An OpenFrameworks addon to receive multitouch event notifications from generic, custom made input devices. As the name suggests, it uses serial communication (@9600 baud), so it can work with devices connected via USB, bluetooth, etc…
I originally created this addon to work with input devices built around the MPR121 sensor; if you want a quick and easy way to create your own, here's a compatible firmware.
Protocol
The addon uses a simple and compact 1 byte protocol: if you're making your own hardware and firmware, just follow these guidelines.Every received byte is considered a separate touch event, formatted this way:
bit index: 1 2 3 4 5 6 7 8
use: PPPTThe 6 most significant bits are used to store the address of the pin that generated the event. This means the protocol allows 64 available addresses.
The 2 least significant bits store the event type: 0 means "touch down" 1 means "touch up"
Since 2 bits are used and only 2 event types are implemented, there's free space in this field: this is because I will probably need to implement more event types for a project I'm working on.