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SerialTFT

Arduino sketch for TFT display rendering using serial commands.

This is a sketch for using an arduino compatible micro-controller with a TFT screen as an external user interface controlled by sending simple graphics primitive commands over a serial connection.

It is currently set up to use the TFT eSPI library, but it should be easy to adapt. It has been tested using a Seeed Wio Terminal device.

It makes use of the TFT eSPI Sprite class. This greatly accelerates rendering speed. More information here: http://blog.nostatic.org/2021/10/speeding-up-arduino-tft-tftespi-writes.html.

The Sprite-based rendering requires that the device have enough ram to use as a full-screen buffer. It would be simple to change the code to do direct rendering, though.

Because the Sprite-based rendering uses a temporary buffer, the "us" (update screen) command is required to render the buffer to the actual TFT. The idea is that you issue a series of rendering commands, and then do "us" to push what you have rendered to the display.

Current Command Set

The current command set is limited to drawing rectangles and text. I plan to add additional functionality as I need it.

Commands muse be terminated with a newline ('\n') and should not exceed 255 characters.

us - Update screen

fs <color565> - fill screen with color
  
dr <x> <y> <width> <height> <color565> - draw rectangle
  
fr <x> <y> <width> <height> <color565> - draw filled rectangle

tf <font> - set text font (current fonts are "FFSB9", FFSB12", FFSB18", FFSB24")

tc <color565> - set text color
  
ta <alignment> - set text alingment ("t/m/b + l/c/r" - ie: "tc" for top center)

dt <x> <y> <text> - draw text