Touch pads are accelerating in embedded projects. And there are several reasons for this. One of them – more and more microcontroller manufacturers add internal capacitance sensor modules that can be easily used for interfacing touch sensors. Another reason would be simplicity – no moving parts so they are vibration, waste, dirt proof. The only thing is missing – “click” sound when pressing the button.
Giorgios Lazaridis has been working on touch pad prototype. This isn’t his first attempt to use touch pad in projects. He made some conclusion from earlier attempt and now he is ready to share some thoughts about it. He experienced that touch pads shouldn’t be interfaced with long wires, what leads to unpredictable readings. So his next step is to make a dedicated PIC circuit which sits just on other side of touch pad (double sided PCB) receives clear readings of sensors. Then microcontroller generates BCD code that can be sent to the next stage.