From Trammell Hudson's Projects
Desired features for Port-O-Rotary v2:
- Pulse decoder - Done!
- Ringer driver - Needs work.
- On-hook detection - Done!
- Battery charger - Done! (Built into the FONA)
- Dial tone injection (350 and 440 Hz) - Done! (Built into the FONA)
- Dialup modem support - sort of. Connection quality is very bad.
Source code: github/osresearch/rotary
Circuit board in the ITT 500 series phone:
|E2||A = bell gray/red||E1||G = RJ45 yellow|
|F = dial blue||K||C = bell gray||L2 = RJ45 red, bell red, hook relay|
|GN = dial white, RJ45 white||B = RJ22 black||L1 = RJ45 green, hook relay gray/green, bell black|
|RR = dial green|
|R = RJ22 red and white, dial white, relay|
The rotary dial has two switches: the white one is open at rest and closed when the dial is disturbed from the rest position, the blue/green is normally closed, but opens when the rotor crosses a number.