Using a TTP223 1-key capacitive touch module with MicroPython.

I was going to write a driver for this module, but it's pretty much just a drop in replacement for a push button. No driver needed.

The module features 3 pins, VCC, I/O and GND and has a red LED which illuminates when a touch is detected and the I/O pin goes HIGH.

It's sensitive enough to detect my finger around 3mm away from the touch pad.

Basic usage

from machine import Pin
import time

d3 = Pin('D3', Pin.IN, Pin.PULL_DOWN)

while True:
    print(d3.value())
    time.sleep_ms(100)

Using interrupts

from machine import Pin

d3 = Pin('D3', Pin.IN, Pin.PULL_DOWN)
d4 = Pin('D4', Pin.IN, Pin.PULL_DOWN)

def touch(pin):
    print('Touched {}'.format(pin.name()))

d3.irq(touch, Pin.IRQ_FALLING)
d4.irq(touch, Pin.IRQ_FALLING)

There are 2 pads A and B which can be bridged with a dab of solder to change the trigger mode.

• VCC-GND STM32F407VET6 mini $15.47 AUD
• TTP223 Capacitive Touch Module $0.22 AUD
• Female-Female Dupont wires $0.64 AUD

• micropython.org
• TTP223 datasheet

Licensed under the MIT License.