The code doesn't use any library, the SPI is set by inline C. Using 1.8" TFT with ST7735 driver, displaying universal 5x7 fonts for 0 to 9. The code works only for ATMEGA328, I used Arduino Nano.
Voltage input at A0. Bitmap is BMP of 16 (5:6:5) bit color, it uses about 85% of the RAM.
' TFT...