The Sourcecode is based on an elektor project (https://www.elektormagazine.de/magazine/elektor-201610/39858). Compatible with HC-05/06 slave mode, support Bluetooth ...
Tested with the Robotdyn 16 Keys I2C Capacitive Touch TTP229 Module Robotdyn Capacitive Touch Disk Pad. uint16_t readKeys() - Read data from TTP229 and return states of 16 keys in bitmap ...