5.1 Keyfob

The keyfob software primarily operates in the Deep Sleep mode to reduce current consumption. Pressing a button initiates a wake-up along with a KeeLoq package transmission.

For debugging purposes, disable the Sleep mode by using a compiler define to interface with the keyfob via the virtual COM port. This is necessary to store the serial number and the seed value to the keyfob.

The two buttons SW1 and SW2 are currently configured for package transmission, reflected in the function code of the KeeLoq package. To transmit a seed package for pairing, hold down the SW2 button while pressing the SW1 button.
Figure 5-1. Flow Diagram