barren stone
I've had this original Bell Telephone system phone "speaker" since it was retired from service around 1985 or so. This was a precursor to the "speakerphone" in that all it did was amplify the remote party's voice so others in the room could listen in on a conversation. This avacoda colored unit matched the four line avacado colored phone that my dad had on his office desk in the 80's. I held on to it with the hope of using it for a project and I've finally found one.
I added an ESP32 and a 98357a I2S audio amp, and a single WS2811 RGB LED to light up the volume knob. I then added a USBC LiPo battery charger and a LiPo battery I recovered from a discarded vape pen.
I also used an ADC pin on the ESP32 to read the pot (it returns from 0 to 3.7v) and also used another pin to read the switch that clicks when you rotate the pot all the way CCW. I was able to read the POT and use it to adjust the volume of the media player, but I don't know if I am going to keep that functionality. I also have the unit making text to speech announcements when family members enter/exit work and home zones.
The nice part is, I can repurpose this box whenever I like just by re-writing some YAML and the OTA updating it! Super cool! ππ
low grove
