App note: A method of enabling more touch pads With 5-ch CapTouch module on LPC804 MCU

App note from NXP demonstrating capacitive pin channels expansion on LPC804 MCU with SWM (switch matrix) and scan sequences. Link here (PDF) The CapTouch module on LPC804 supports only 5 channels by hardware. Normally, the device with up to 5 channels can fulfill some simple use cases. But if more channels are required by the […]

Capacitive touch sensing with a single ADC pin

Capacitive sense buttons and pads are awesome, but many of the available systems are either propitiatory or require a dedicated IC. Toumas decided to code his own based on a closed source Atmel example where a single ADC pin is used for capacitive sensing. He reverse engineered it, and documented his results: I’ve been thinking […]

App note: Layout and physical design guidelines for capacitive sensing

We think DIY capacitive touch sensing buttons, and sliders are cool. Designing and shaping your capacitive panels can be a pain. Here is an app note by Microchip that covers all the basics required to get your capacitive touch sensing project started. This app note starts with which pad shape and size is best suited […]

App note: Using Microchip’s capacitive sensing module

Capacitive sensing is used in tons of stuff like buttons, sliders, touch panels and proximity sensors. We like it because you only need to design the various buttons/sliders directly on the PCB and it works even under a face plate. It works by measuring the changing capacitance between a pad and a users finger as […]