Operation with alternate SPI0 port on ESP-8266 #7
Description
The ESP-12 (for example) has pins that access the SPI0 port (normal SPI is SPI1, SPI0 is used in the ESP to access the onboard FLASH) and it /can/ be used in sketches, if, and only if, you allow the ESP to arbitrate via the HWCS pin:
https://arduino-esp8266.readthedocs.io/en/latest/libraries.html#spi
For this mode the CS will be controlled by hardware as you can’t handle the CS line with a GPIO, you never actually know when the arbiter is going to grant you access to the bus so you must let it handle CS automatically.
As it happens, in my application, I need the SPI1 MOSI pin, D7 / GPIO13, for it's other function, as RX2 via Serial.swap()
https://arduino-esp8266.readthedocs.io/en/latest/reference.html#serial
I don't believe the software serial will work, because I'm also running multiple other services and it has issues:
https://github.com/plerup/espsoftwareserial/issues
This is supported in /Bodmer/TFT_eSPI
Bodmer/TFT_eSPI#74 (comment)
However that library does not support hardware scrolling.