With Arduino Mbed OS RP2040 Boards on Arduino IDE, this post show how to connect 128x160 ST7735 SPI TFT to Raspberry Pi Pico, and control with TFT_eSPI library in Arduino framework.
The TFT Display:
The TFT display used here is a 1.8 inch 128x160 ST7735 SPI TFT. The
product page is here: 1.8inch SPI Module ST7735S SKU:MSP1803.
Connection between Raspberry Pi Pico and 128x160 ST7735 SPI TFT:
The connection follow the default setup in TFT_eSPI library, Setup60_RP2040_ILI9341.h.
ST7735 TFT Pico
Pin# name
1 VCC 5V/3.3V 3V3 (pin 36)
2 GND Ground GND (pin 38)
3 CS chip select 20 (pin 26)
4 RESET reset 19 (pin 25)
5 A0 reg/data 18 (pin 24)
6 SDA SPI data 3 (pin 5)
7 SCK SPI clock 2 (pin 4)
8 LED Backlight 3V3
The library used is
Bodmer/TFT_eSPI, a Arduino and PlatformIO IDE compatible TFT library optimised for the
Raspberry Pi Pico (RP2040), STM32, ESP8266 and ESP32 that supports different
driver chips.
To install TFT_eSPI in Arduino IDE, simple open Library Manager, search and
install TFT_eSPI by Bodmer.
Take a note on the Tips section in the TFT_eSPI Library page:
If you load a new copy of TFT_eSPI then it will overwrite your setups if they are kept within the TFT_eSPI folder. One way around this is to create a new folder in your Arduino library folder called "TFT_eSPI_Setups". You then place your custom setup.h files in there. After an upgrade simply edit the User_Setup_Select.h file to point to your custom setup file.
If you load a new copy of TFT_eSPI then it will overwrite your setups if they are kept within the TFT_eSPI folder. One way around this is to create a new folder in your Arduino library folder called "TFT_eSPI_Setups". You then place your custom setup.h files in there. After an upgrade simply edit the User_Setup_Select.h file to point to your custom setup file.
Here is how I practice it:
- create a new folder in your Arduino library folder called
"TFT_eSPI_Setups".
- copy TFT_eSPI/User_Setups/Setup60_RP2040_ILI9341.h to new created
"TFT_eSPI_Setups" folder, rename as Setup60_RP2040_ST7735.h.
- Edit Setup60_RP2040_ST7735.h for ST7735:
// USER DEFINED SETTINGS
// Set driver type, fonts to be loaded, pins used and SPI control method etc
//
// See the User_Setup_Select.h file if you wish to be able to define multiple
// setups and then easily select which setup file is used by the compiler.
//
// If this file is edited correctly then all the library example sketches should
// run without the need to make any more changes for a particular hardware setup!
// Note that some sketches are designed for a particular TFT pixel width/height
// ##################################################################################
//
// Section 1. Call up the right driver file and any options for it
//
// ##################################################################################
// Tell the library to use 8 bit parallel mode (otherwise SPI is assumed)
//#define TFT_PARALLEL_8_BIT
// Display type - only define if RPi display
#define RPI_DISPLAY_TYPE // 20MHz maximum SPI
// Only define one driver, the other ones must be commented out
//#define ILI9341_DRIVER
#define ST7735_DRIVER // Define additional parameters below for this display
//#define ILI9163_DRIVER // Define additional parameters below for this display
//#define S6D02A1_DRIVER
//#define RPI_ILI9486_DRIVER // 20MHz maximum SPI
//#define HX8357D_DRIVER
//#define ILI9481_DRIVER
//#define ILI9486_DRIVER
//#define ILI9488_DRIVER // WARNING: Do not connect ILI9488 display SDO to MISO if other devices share the SPI bus (TFT SDO does NOT tristate when CS is high)
//#define ST7789_DRIVER // Full configuration option, define additional parameters below for this display
//#define ST7789_2_DRIVER // Minimal configuration option, define additional parameters below for this display
//#define R61581_DRIVER
//#define RM68140_DRIVER
//#define ST7796_DRIVER
//#define SSD1963_480_DRIVER
//#define SSD1963_800_DRIVER
//#define SSD1963_800ALT_DRIVER
//#define ILI9225_DRIVER
// Some displays support SPI reads via the MISO pin, other displays have a single
// bi-directional SDA pin and the library will try to read this via the MOSI line.
// To use the SDA line for reading data from the TFT uncomment the following line:
// #define TFT_SDA_READ // This option is for ESP32 ONLY, tested with ST7789 display only
// For ST7735, ST7789 and ILI9341 ONLY, define the colour order IF the blue and red are swapped on your display
// Try ONE option at a time to find the correct colour order for your display
#define TFT_RGB_ORDER TFT_RGB // Colour order Red-Green-Blue
// #define TFT_RGB_ORDER TFT_BGR // Colour order Blue-Green-Red
// For ST7789, ST7735 and ILI9163 ONLY, define the pixel width and height in portrait orientation
// #define TFT_WIDTH 80
#define TFT_WIDTH 128
// #define TFT_WIDTH 240 // ST7789 240 x 240 and 240 x 320
#define TFT_HEIGHT 160
// #define TFT_HEIGHT 128
// #define TFT_HEIGHT 240 // ST7789 240 x 240
// #define TFT_HEIGHT 320 // ST7789 240 x 320
// For ST7735 ONLY, define the type of display, originally this was based on the
// colour of the tab on the screen protector film but this is not always true, so try
// out the different options below if the screen does not display graphics correctly,
// e.g. colours wrong, mirror images, or tray pixels at the edges.
// Comment out ALL BUT ONE of these options for a ST7735 display driver, save this
// this User_Setup file, then rebuild and upload the sketch to the board again:
//#define ST7735_INITB
#define ST7735_GREENTAB
// #define ST7735_GREENTAB2
// #define ST7735_GREENTAB3
// #define ST7735_GREENTAB128 // For 128 x 128 display
// #define ST7735_GREENTAB160x80 // For 160 x 80 display (BGR, inverted, 26 offset)
// #define ST7735_REDTAB
// #define ST7735_BLACKTAB
// #define ST7735_REDTAB160x80 // For 160 x 80 display with 24 pixel offset
// If colours are inverted (white shows as black) then uncomment one of the next
// 2 lines try both options, one of the options should correct the inversion.
// #define TFT_INVERSION_ON
// #define TFT_INVERSION_OFF
// ##################################################################################
//
// Section 2. Define the pins that are used to interface with the display here
//
// ##################################################################################
// If a backlight control signal is available then define the TFT_BL pin in Section 2
// below. The backlight will be turned ON when tft.begin() is called, but the library
// needs to know if the LEDs are ON with the pin HIGH or LOW. If the LEDs are to be
// driven with a PWM signal or turned OFF/ON then this must be handled by the user
// sketch. e.g. with digitalWrite(TFT_BL, LOW);
// #define TFT_BL 32 // LED back-light control pin
// #define TFT_BACKLIGHT_ON HIGH // Level to turn ON back-light (HIGH or LOW)
// We must use hardware SPI, a minimum of 3 GPIO pins is needed.
// Typical setup for the RP2040 is :
//
// Display SDO/MISO to RP2040 pin D0 (or leave disconnected if not reading TFT)
// Display LED to RP2040 pin 3V3 or 5V
// Display SCK to RP2040 pin D2
// Display SDI/MOSI to RP2040 pin D3
// Display DC (RS/AO)to RP2040 pin D18 (can use another pin if desired)
// Display RESET to RP2040 pin D19 (can use another pin if desired)
// Display CS to RP2040 pin D20 (can use another pin if desired, or GND, see below)
// Display GND to RP2040 pin GND (0V)
// Display VCC to RP2040 5V or 3.3V (5v if display has a 5V to 3.3V regulator fitted)
//
// The DC (Data Command) pin may be labelled AO or RS (Register Select)
//
// With some displays such as the ILI9341 the TFT CS pin can be connected to GND if no more
// SPI devices (e.g. an SD Card) are connected, in this case comment out the #define TFT_CS
// line below so it is NOT defined. Other displays such at the ST7735 require the TFT CS pin
// to be toggled during setup, so in these cases the TFT_CS line must be defined and connected.
// For the Pico use these #define lines
#define TFT_MISO 0
#define TFT_MOSI 3
#define TFT_SCLK 2
#define TFT_CS 20 // Chip select control pin
#define TFT_DC 18 // Data Command control pin
#define TFT_RST 19 // Reset pin (could connect to Arduino RESET pin)
//#define TFT_BL // LED back-light
//#define TOUCH_CS 21 // Chip select pin (T_CS) of touch screen
// ##################################################################################
//
// Section 3. Define the fonts that are to be used here
//
// ##################################################################################
// Comment out the #defines below with // to stop that font being loaded
// The ESP8366 and ESP32 have plenty of memory so commenting out fonts is not
// normally necessary. If all fonts are loaded the extra FLASH space required is
// about 17Kbytes. To save FLASH space only enable the fonts you need!
#define LOAD_GLCD // Font 1. Original Adafruit 8 pixel font needs ~1820 bytes in FLASH
#define LOAD_FONT2 // Font 2. Small 16 pixel high font, needs ~3534 bytes in FLASH, 96 characters
#define LOAD_FONT4 // Font 4. Medium 26 pixel high font, needs ~5848 bytes in FLASH, 96 characters
#define LOAD_FONT6 // Font 6. Large 48 pixel font, needs ~2666 bytes in FLASH, only characters 1234567890:-.apm
#define LOAD_FONT7 // Font 7. 7 segment 48 pixel font, needs ~2438 bytes in FLASH, only characters 1234567890:-.
#define LOAD_FONT8 // Font 8. Large 75 pixel font needs ~3256 bytes in FLASH, only characters 1234567890:-.
//#define LOAD_FONT8N // Font 8. Alternative to Font 8 above, slightly narrower, so 3 digits fit a 160 pixel TFT
#define LOAD_GFXFF // FreeFonts. Include access to the 48 Adafruit_GFX free fonts FF1 to FF48 and custom fonts
// Comment out the #define below to stop the SPIFFS filing system and smooth font code being loaded
// this will save ~20kbytes of FLASH
#define SMOOTH_FONT
// ##################################################################################
//
// Section 4. Other options
//
// ##################################################################################
// Define the SPI clock frequency, this affects the graphics rendering speed. Too
// fast and the TFT driver will not keep up and display corruption appears.
// With an ILI9341 display 40MHz works OK, 80MHz sometimes fails
// With a ST7735 display more than 27MHz may not work (spurious pixels and lines)
// With an ILI9163 display 27 MHz works OK.
// #define SPI_FREQUENCY 1000000
// #define SPI_FREQUENCY 5000000
// #define SPI_FREQUENCY 10000000
// #define SPI_FREQUENCY 20000000
// #define SPI_FREQUENCY 32000000
#define SPI_FREQUENCY 70000000
// Optional reduced SPI frequency for reading TFT
#define SPI_READ_FREQUENCY 20000000
// The XPT2046 requires a lower SPI clock rate of 2.5MHz so we define that here:
#define SPI_TOUCH_FREQUENCY 2500000
- Edit the User_Setup_Select.h file to point to the custom setup file,
Setup60_RP2040_ST7735.h.
//#include <User_Setup.h> // Default setup is root library folder
#include <../TFT_eSPI_Setups/Setup60_RP2040_ST7735.h>
After then, you can try examples installed with TFT_eSPI, or your own
exercises.
My exercise: Pico_ST7735_SPI_128x160_.ino
/*
* Test 128x160 ST7735 SPI TFT Display,
* using TFT_eSPI library
*/
#include <TFT_eSPI.h>
#include <SPI.h>
TFT_eSPI tft = TFT_eSPI();
void setup() {
tft.init();
tft.setRotation(0);
tft.setTextSize(1);
}
void loop() {
tft.setRotation(0);
tft.fillScreen(TFT_BLACK);
tft.drawPixel(10, 10, TFT_WHITE);
tft.drawPixel(10, 150, TFT_WHITE);
tft.drawPixel(118, 150, TFT_WHITE);
tft.drawPixel(118, 10, TFT_WHITE);
delay(1000);
int margin = 10;
for(int x=margin; x<=TFT_WIDTH-margin; x++){
tft.drawPixel(x, margin, TFT_WHITE);
delay(10);
}
for(int y=margin; y<=TFT_HEIGHT-margin; y++){
tft.drawPixel(TFT_WIDTH-margin, y, TFT_WHITE);
delay(10);
}
for(int x=TFT_WIDTH-margin; x>=margin; x--){
tft.drawPixel(x, TFT_HEIGHT-margin, TFT_WHITE);
delay(10);
}
for(int y=TFT_HEIGHT-margin; y>=margin; y--){
tft.drawPixel(margin, y, TFT_WHITE);
delay(10);
}
delay(500);
tft.setRotation(1);
//tft.fillScreen(TFT_BLACK);
tft.setTextColor(TFT_RED, TFT_BLACK);
tft.drawString("RED", 10, 10, 4);
delay(1000);
tft.setRotation(2);
//tft.fillScreen(TFT_BLACK);
tft.setTextColor(TFT_GREEN, TFT_BLACK);
tft.drawString("GREEN", 10, 10, 4);
delay(1000);
tft.setRotation(3);
//tft.fillScreen(TFT_BLACK);
tft.setTextColor(TFT_BLUE, TFT_BLACK);
tft.drawString("BLUE", 10, 10, 4);
delay(1000);
delay(3000);
}
