Technical description for
HC20 schematic
Rev. A
Date:
2014-09-26
Init: TOP
Side 3/7
Micro controller
The uC handles all key scan, Backlight and LED operation and of cause setup and data stream to
the RF transmitter.
When the handset is not used, the microcontroller (uC) enters a low-power mode where all external
clock frequencies are switched off. It wakes up and scans the key matrix to see if a button have
been pressed and then power down again.
If a button is pressed down, the uC wakes up and start communicating with the RF transmitter on
the I2C bus. It starts by initializing the transmitter and afterwards it start transmitting the actual data
packages to the buffer of the RF transmitter.
