Electrodes : 12 [default]
Arduino pins: 5 (for the buttons: from pin #2 to pin #13, using two pins for one button)
Arduino adafruit shield: 12 pins using this shield: https://www.adafruit.com/product/1982
(need testing, not sure)
Maximum pins: Connecting multiple boards
You can reach a maximum pins connecting touch boards between each other creating a series. In this case, one board should remain as a Master Board and 6 other boards will be attached to the master board as slaves.
For this you will need:
- Pin RX to receive the data from other boards, connecting it to the TX pins on the all other boards.
- Connect both power and ground pins(5V and GND on the bottom of the board) from the Master Board to all other boards 5V and GND pins.
- Connect A0(analog 0 pin) from the Master Board to the A0 pin on the first Slave Board
- Connect A1(analog 1 pin) from the Master Board to the A1 pin on the second Slave Board
- Connect A2(analog 2 pin) from the Master Board to the A2 pin on the third Slave Board
- Connect A3(analog 3 pin) from the Master Board to the A3 pin on the fourth Slave Board
- Connect A4(analog 4 pin) from the Master Board to the A4 pin on the fifth Slave Board
- Connect A5(analog 5 pin) from the Master Board to the A5 pin on the six Slave Board
Schematic was taken from the Multi-board touch MP3 demo github
Maximum Electrodes: 12 * 7 = 84 total
Additional Arduino pins: 5 * 7 = 35 total ( Total: 119 together with Electrodes)
With Adafruit shield: 12 * 7 = 84 ( Total: 168 Electrodes together with Arduino pins from the Adafruit shield)