These ST7789 displays are great : ) The pin naming conventions confused me for ages, they are different between the boards, some of the code, and the actual function : )
RES, RST and RS confused me for a while, they all sound the same. Also SDA/SCL is nothing to do with I2C. I tried to write it down, I think this is accurate:
Name Alternative Name Actual Function
SDA SPI MOSI SCL SPI SCK DC RS Register Select (low=Command, high=Data) RES RST Reset (low will reset the chip) CS Chip Select, can tie to GND BLK Backlight (low=off, high=on)
Anyway, an even better solution for the Hershey fonts would be two scale variables, to separately control width and height scaling factors. Maybe that is gilding the lily too much! :)
Top Comments