Specifications
- 16 keys
- TTP229 driver in 16-key mode
- Only two pins needed (clock and data)
- The module goes on top of the tower
- Power 3.3 V (assumed, the TTP229 works from 2.4–5.5 V)
- Current ≈ 1 mA (estimate)
- Does not use the I2C bus, even though the chip pins are called SCL and SDO, the TTP229 has its own interface on IO7 and IO8
- Uses: calculator, menu control, entering a PIN
Pins
| Pin | Function |
|---|---|
| IO7 | Clock (KEY_CLK) |
| IO8 | Data (KEY_DIN) |
Wiring diagram
Example code
Try the example Keypad piano right in your browser in Eduingo AI Lab. Each of the 16 keys plays a different tone. The program starts at 200 Hz and adds 60 Hz as many times as the key's number: adding over and over is really multiplication. So key 1 plays 260 Hz and key 16 plays 1160 Hz. Try playing a tune or changing the step between the tones.