Original Contents of file notes.txt as contained in file "Pulse2Tone_2012_01_22.zip"
(Hyperlinks added by JvK) (The PDF-file only contains a picture, which is directly stored as JPG in this repository)
main.c - source code main.h - header file Schematic_v1-0.png - adapter schematic wd_we500c-d.pdf - phone schematicEnd of notes
Source code compiled with AVR Studio v4.18 + WinAVR for attiny45, optimization -O1. SUT_CKSEL fuse should be programmed for external 8 Mhz crystal oscillator.
The converter originally designed to be mounted/wired inside the phone.
It has to be connected in parallel to the phone line, but _after_ the hook switch, e.g. between terminals C and F/RR on the phone schematic.
Rotary dial (all 4 wires) has to be disconnected from the phone and wired to the adapter (see schematic).
The adapter is polarity sensitive.
Terminal C is just a solder pad, so I ended up using L2 instead (its a nice screw terminal).