This post is long overdue. Â The hardware has been complete (enough) for weeks now, and the software has been improving incrementally. Â It is the impending arrival of the Maker Faire that finally prodded me enough to finish writing this up. Â I’ll be there showing this off. Â Here’s what the completed project (mostly) looks like: Â (more details after the break)
When we last left our hero, he had just finished ripping the guts out of the tele-coupler. Â The next obvious step was to actually use them. Â First, I needed to take off the (perfectly good) microphone and speaker, and connect them to the completely untested mic and speaker in the telephone handset. Â So, out comes the desoldering braid:
Then solder the tiny leads to the spade lugs of the handset, cover the shrink tubing, and stress relieve:
The board is mounted using foam mounting tape (2 layers), and the cord that goes to the modem is routed out the hole originally used by the phone’s main cord. Â The amplifier needs a 9V power source, and I didn’t have time to build a step-up (boost) converter for the 5V the arduino get from the FTDI cable, so I decided to leave the 9V connector dangling out that hole as well, and the phone needs a 9V battery to work. Â It’s not ideal, but it was quick. Â Now Â I just needed to get the software working, but more about that later.