implement support for st7735 display

[dpeddi]

initial support for st7735 display

[dpeddi]

[dpeddi]

the original developer used ThingPulse/esp8266-oled-ssd1306, if someone who have ssd1306 would move to adafruit/Adafruit_SSD1306 probably there would be less ifdef.

Next step may be to create a display "class" to be referenced from espurna itself for ip address/ssid and/or relay status..

[mcspr]

the original developer used ThingPulse/esp8266-oled-ssd1306, if someone who have ssd1306 would move to adafruit/Adafruit_SSD1306 probably there would be less ifdef.

idk about that. perhaps, availability and / or esp8266 quirks were handled better originally, but still it feels like Adafruit option is mostly targeted at other Arduino boards.
also check out https://github.com/lexus2k/ssd1306, despite the name it handles both of these displays.

Next step may be to create a display "class" to be referenced from espurna itself for ip address/ssid and/or relay status..

maybe. depends on what exactly relays will do. e.g. do we create sort-of 'window' / region and allow external thing to fully control it, or keep some specific spaces for 'info' and only allow data input

let me think about the example / pio.ini code a bit, I'll merge the PR after that