Bread Board PBX (BB_PBX) - Ring Generator

 I am working on a PICAXE ring generator for the BB_PBX. Since the SLIC modules require two pins with signal timings to ring them, I can reduce the I/O pins needed from the PIC32 and simplify the software too.

The PICAXE 08M2 chip will generate 20 Hz ringing signal on pin 5 C.2 and the ring mode signal on pin 6 C.1. The PICAXE is also taking care of the ring cadence (ringing then silence then ringing, etc.) and signal timing. This will no longer need to be handled in a software, so a single I/O pin connect to for example - Ring1 line brought high to start ringing line 1, etc.

The logic gates connected to the PICAXE route the ringing to one of 3 SLIC modules (technically possible to ring all lines if needed). It is also connected to the SHK (Hook) of the SLIC module so it will kill ringing when the phone goes off hook instantly, since with the software there could be delays.

Here is the PICAXE Blockly code for the ringer.