Overview

Kaluma library for ST7735 (Color TFT LCD driver).

You can get displays from belows:

• 1.44" 128x128 (from Adafruit)
• 1.8" 128x160 (from Adafruit)

Wiring

Here is a wiring example for SPI0.

Raspberry Pi Pico	ST7735
3V3	3V3
GND	GND
GP19 (SPI0 TX)	DATA (MOSI)
GP18 (SPI0 CLK)	CLK
GP20	D/C
GP21	RST
GP17	CS

Install

npm i https://github.com/niklauslee/st7735

Usage

You can initialize ST7735 driver using SPI interface as below:

const {ST7735} = require('st7735');
const st7735 = new ST7735();

var options = { // ST7735R 1.44"
  dc: 20,
  rst: 21,
  cs: 17
};

/*
var options = { // ST7735R 1.8"
  width: 128,
  height: 160,
  xstart: 0,
  ystart: 0,
  dc: 20,
  rst: 21,
  cs: 17
}
*/

st7735.setup(board.spi(0), options);
const gc = st7735.getContext();
gc.drawRect(0, 0, width, height);

You can use BufferedGraphicsContext instead of general callback-based graphics context as below:

// buffered graphic context
var gc = st7735.getContext('buffer');
gc.drawRect(0, 0, width, height);
gc.display(); // must call if buffered graphic context
...

Note that BufferedGraphicsContext allocates a lot of memory (32KB for 128x128 resolution).

API

Class: ST7735

A class for ST7735 driver communicating with SPI interface.

new ST7735()

Create an instance of ST7735 driver for SPI interface.

st7735.setup(spi[, options])

• spi <SPI> An instance of SPI to communicate.
• options <object> Options for initialization.
  • width <number> Width of display in pixels. Default: 128.
  • height <number> Height of display in pixels. Default: 128.
  • xstart <number> x-start of display in pixels. Default: 2.
  • ystart <number> y-start of display in pixels. Default: 3.
  • dc <number> Pin number for DC. Default: -1.
  • rst <number> Pin number for RST (Reset). Default: -1.
  • cs <number> Pin number of CS (Chip select). Default: -1.
  • rotation <number> Rotation of screen. One of 0 (0 degree), 1 (90 degree in clockwise), 2 (180 degree in clockwise), and 3 (270 degree in clockwise). Default: 0.

Setup ST7735 driver for a given SPI bus and options based on the below table.

Display Types	height	width	xstart	ystart
1.44"	128	128	2	3
1.8"	128	160	0	0

st7735.getContext([type])

• type: Optional. Type of graphic context. If "buffer" is given, BufferedGraphicContext is returned.
• Returns: <GraphicContext> An instance of graphic context for ST7735.

Get a graphic context.

Note that BufferedGraphicContext is much faster, but it consumes memory a lot.

Note that gc.getPixel(x, y) function is supported only if BufferedGraphicsContext.

Examples

• ex_144.js (1.44" 128x128 resolution)
• ex_18.js (1.8" 128x160 resolution)