GS-232A
Computer Control Interface
for Antenna Rotators

COM port settings:
1200 baud, 8 data bits, 1 stop bit, no parity, no handshake

Angles:
0-45    north
46-135  east
136-225 south
226-315 west
316-405 north
406-450 east

Pinout:
pin arduino - pin ATmega328 - name        - direction - configure
2           - PD2           - relay north - out       - push-pull
3           - PD3           - relay east  - out       - push-pull
4           - PD4           - relay south - out       - push-pull
5           - PD5           - relay west  - out       - push-pull
6           - PD6           - key north   - in        - pull-up
7           - PD7           - key east    - in        - pull-up
8           - PB0           - key south   - in        - pull-up
9           - PB1           - key west    - in        - pull-up
13          - PB5           - led         - out       - push-pull