Guide

How to use ST7735 display with Raspberry Pi Pico

Captain Make

Mar 6, 2023 • 2 min read

In this guide we will learn how to use ST7735 TFT displays with Raspberry Pi Pico or any other CircuitPython compatible development board.

Code is licensed under the Open Source MIT License

Supporting Adafruit libraries are licensed under the open source MIT License

What you need

Raspberry Pi Pico or compatible board with CircuitPython installed
Any TFT display that supports ST7735 (s,r) driver
Jumper wires
USB cable to connect to the power source

Wiring

You can use any Raspberry Pi Pico board and ST7735 TFT display. For this guide we are using original Raspberry Pi Pico and ST7735S TFT display from Waveshare.

If you are using a Waveshare ST7735S for pico, you can simply attach Pico board using the attached headers, otherwise connect the following

Display DC to board.GP8
Display RST to board.GP12
Display MOSI to board.GP11
Display SCK to board.GP10
Display CS to board.GP9

Pi Pico attached to the Waveshare ST7735S display

The code

Copy the following code in code.py file on your development board. Be sure to check out the inline comments for the explanation.

# We will use displayio as a main rendering library
import board, time, terminalio, busio, displayio
# This helps in label rendering
from adafruit_display_text import label
# CircuitPython ST7735 driver, make sure to use st7735r (not st7735)
from adafruit_st7735r import ST7735R

# Release any resources currently in use for the displays
displayio.release_displays()

# Define all pins
BL = board.GP13
DC = board.GP8
RST = board.GP12
MOSI = board.GP11
SCK = board.GP10
CS = board.GP9

# Initialise SPI bus and display
spi = busio.SPI(SCK, MOSI=MOSI)
display_bus = displayio.FourWire(spi, command=DC, chip_select=CS, reset=RST)
display = ST7735R(display_bus, width=160, height=128, rotation=270, bgr=True)

# Make the display context
splash = displayio.Group()
display.show(splash)

# Background color
color_bitmap = displayio.Bitmap(160, 128, 1)
color_palette = displayio.Palette(1)
color_palette[0] = 0x00FFFF  # Cyan

bg_sprite = displayio.TileGrid(color_bitmap, pixel_shader=color_palette, x=0, y=0)
splash.append(bg_sprite)

# Draw a label
text_group = displayio.Group(scale=2, x=11, y=64)
text = "Monty Python!"
text_area = label.Label(terminalio.FONT, text=text, color=0x000000)
text_group.append(text_area)

splash.append(text_group)
time.sleep(1)

# In the next step we will display 3 different images in a loop,
# Remove text group before that for a clean transition
splash.remove(text_group)

# For this to work, you will need to make sure you have the BMP files downloaded and placed
# inder img/ folder on your dev board
while True:
    for n in range(3):
        # loop through 1.bmp, 2.bmp, 3.bmp indefinitely
        bitmap = displayio.OnDiskBitmap("img/" + str(n) + ".bmp")
        tile_grid = displayio.TileGrid(bitmap, pixel_shader=bitmap.pixel_shader)
        splash.append(tile_grid)
        # Increase the sleep if you wanna appreciate the bitmaps for a little longer
        time.sleep(1)