The Breakout Comms Board offers a convenient way to connect multiple touch switches (up to 15 per board) to a media player, an Arduino, Beagle board, or other microcontroller with a UART port, to enable the touch sensors to control that device in some way. Perhaps to select audio-visual tracks on a media player.

All the signal lines from the touch switches are connected together (star connection) and routed to the serial pin on a 6-pin header. This pin can be connected to the UART Rx pin on the target micro-controller. Each touch switch can be programmed to transmit a different character sequence when touched so that the target micro-controller can determine which touch switch has been operated. Of course, only one touch switch can be operated at a time otherwise their communications might interfere with each other. The communications are fast, however, so the chances of conflict are small.

B0716 Schematic.pdf

The touch switch connectors each have 3-pins and are arranged in banks of 5. The “RED” and “BLK” labels at the end of each row indicate which way round to push on the plugs, to correctly connect with the red and black cores of the touch switch cables.

One of these connectors, the one adjacent to the reset switch, is specifically for use when using QtBtn to communicate with a touch switch. The power to the touch switch connected at this position can be interrupted by pressing the reset switch. This restarts the time-window when communications with the touch switch can be established for uploading a new configuration, for example.

The 6-pin header at one end of the board routes the serial communication as well as providing power for the touch switches.
The pin-out is:
1 - Unused
2 – RxD
3 – TxD
4 – Vcc (+)
5 – Unused
6 – GND (0V)

Dimensions :
Length : 36mm
Length including header pins : 42mm
Width : 36mm
Height : 12mm
Weight, board: 30g