Rev 3 board qualified and a few built

A project log for weeBell - personal central office for POTS phones

weeBell brings the goodness of old telephones into the modern age in a portable package that speaks GUI, Bluetooth and Wifi

dan-julioDan Julio 07/01/2023 at 17:320 Comments

The integrated I2C filter on the Rev 3 boards works and I built up a small set of boards to try to sell on tindie to see if people would be interested in buying weeBell kits.

Old bug found and fixed

Some of my original Teensy code that handled the AG1171 ringing control made its way into the ESP32 code-base.  I used two phones to test the Rev 3 boards I had built to make sure all functions worked.

During testing I noticed that the rotary phone bell would ring but the more modern DECT wireless phone would not.  This made me worry that I had a hardware issue of some kind (not a great feeling after hand building 10 boards).  Connecting the scope to the tip and ring signals showed reasonable voltages during ringing (not what central offices used to generate but close to what the AG1171 spec claimed it would generate).  I was puzzled, until I told the scope to do a set of measurements to get the RMS voltage and it also told me the frequency was 10 Hz.  Oh snap.  I hadn't even noticed the timescale.  My code was generating a ringing frequency half of what it should have been (USA has 20 Hz ringing frequency).  Simple code fix.  But what was funny is that in all the years playing with this stuff (from Teensy days through weeBell) I had never recognized that when the phone rang it was way too slow of a ring.  But instantly my brain recognized the fixed ring as the way it should sound. 

Also slight GUI mods

I made a small change to the background of the slider and slide-switch widgets so they show up better on the settings page.

Version 0.2 firmware will be pushed shortly.