Shrink the Hardware

[KDMcMullan]

It's nice, but it presently uses a ESP32 coded with TASMOTA, and a serial link to an Arduino.
I think the entire functionality could be ported to the ESP32. Unfortunately, we'd lose some of the nice features TASMOTA supplies.

An ESP-cored alternative would need means to:

• connect and supply WiFi SSID and key
• configure for the MQTT broker
• set pass keys to open and close the "service"
• set the callsign to be used for the service

A webserver would certainly be a favoured means to achieve most of these nice features presently supported by TASMOTA.

[KDMcMullan]

Arduino code has been ported to ESP8266.
Talkie not tested.
Ideally, I'd like to remove MT8770, but it's still required as I can't get https://github.com/Adrianotiger/phoneDTMF to work.

[KDMcMullan]

ESP8266 now completely functional as an MQTT interface. Rather than Talkie, ESP8266Audio has been deployed, which contains ESP8266SAM. this is a very similar voice synthesiser, but much more flexible. It uses the I2C UART as a stable PWM generator for the output.
The MT8870 is still (presently) required to decode DTMF sequences, so the ticket remains open.

[KDMcMullan]

See also this issue.