Bluetooth HC-06 Serial Module - Slave-Only port expander 3V on the ADC pin

3V on the ADC pin or you may damage the chip

For faster Wi-Fi transmission

and detail work

What does the Capacitive Touch Sensor - Toggle measure

terminal C is the button signal output

Bluetooth HC-06 Serial Module - Slave-Only port expander 3V on the ADC pinIf you're looking for a Bluetooth module with a significant amount of documentation, then this item is for you. The Bluetooth HC 06 Serial Module is the go to Bluetooth module for Arduino systems. It's tiny but already allows your target device to both send and receive the TTL data via Bluetooth technology without any help from a serial cable to your computer. Makers love it that is why it is popular. Try one so you can find out yourself!