Arduino - esp32-c3-32s (ILI9341)

This tutorial goes over how to use an ILI9341 TFT screen with the esp32-c3-32s!

Supplies

• (1) esp32-c3-32s
• (1) ILI9341 TFT Screen
• (1) Breadboard
• (8) Jumper cables

Setup

As this board is extremely small compared to the esp32 that preceded it, the pinout information is on the back of the chip.

As this is not a widely used board, I couldn't find a fritzing for it, so I am going to try and make this easy by putting both the board together for you to be able to connect via jumper cables however you please.

esp32-c3-32s Pin	TFT Pin
3v3	VCC
GND	GND
IO7	CS
IO1	RESET
IO2	DC
IO6	SDI (MOSI)
IO4	SCK
LED	3v3

Wiring diagram connecting ILI9341 screen to esp32-c3-32s

Code

For this project, we are using the following libraries:

1. Adafruit_GFX
2. Adafruit_ILI9341

For information on how to install the libraries above please visist https://www.arduino.cc/en/guide/libraries.

The following graphics test code was pulled from https://github.com/adafruit/Adafruit_ILI9341/blob/master/examples/graphicstest/graphicstest.ino

Flash settings

• USB CDC on boot: disabled
• Board: ESP32c3 Dev Module
• CPU Frequency: 80MHZ
• Flash Frequency: 80MHZ
• Flash Mode: DIO
• Flash Size: 4MB
• Partition Scheme: Default 4MB with spiffs
• Upload Speed: 115200

/***************************************************  This is our GFX example for the Adafruit ILI9341 Breakout and Shield  ----> http://www.adafruit.com/products/1651  Check out the links above for our tutorials and wiring diagrams  These displays use SPI to communicate, 4 or 5 pins are required to  interface (RST is optional)  Adafruit invests time and resources providing this open source code,  please support Adafruit and open-source hardware by purchasing  products from Adafruit!  Written by Limor Fried/Ladyada for Adafruit Industries.  MIT license, all text above must be included in any redistribution ****************************************************/#include "SPI.h"#include "Adafruit_GFX.h"#include "Adafruit_ILI9341.h"#define TFT_CS 7#define TFT_DC 2#define TFT_RST 1Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);void setup(){    Serial.begin(9600);    Serial.println("ILI9341 Test!");    tft.begin(4000000);    // read diagnostics (optional but can help debug problems)    uint8_t x = tft.readcommand8(ILI9341_RDMODE);    Serial.print("Display Power Mode: 0x");    Serial.println(x, HEX);    x = tft.readcommand8(ILI9341_RDMADCTL);    Serial.print("MADCTL Mode: 0x");    Serial.println(x, HEX);    x = tft.readcommand8(ILI9341_RDPIXFMT);    Serial.print("Pixel Format: 0x");    Serial.println(x, HEX);    x = tft.readcommand8(ILI9341_RDIMGFMT);    Serial.print("Image Format: 0x");    Serial.println(x, HEX);    x = tft.readcommand8(ILI9341_RDSELFDIAG);    Serial.print("Self Diagnostic: 0x");    Serial.println(x, HEX);    Serial.println(F("Benchmark                Time (microseconds)"));    delay(10);    Serial.print(F("Screen fill              "));    Serial.println(testFillScreen());    delay(500);    Serial.print(F("Text                     "));    Serial.println(testText());    delay(3000);    Serial.print(F("Lines                    "));    Serial.println(testLines(ILI9341_CYAN));    delay(500);    Serial.print(F("Horiz/Vert Lines         "));    Serial.println(testFastLines(ILI9341_RED, ILI9341_BLUE));    delay(500);    Serial.print(F("Rectangles (outline)     "));    Serial.println(testRects(ILI9341_GREEN));    delay(500);    Serial.print(F("Rectangles (filled)      "));    Serial.println(testFilledRects(ILI9341_YELLOW, ILI9341_MAGENTA));    delay(500);    Serial.print(F("Circles (filled)         "));    Serial.println(testFilledCircles(10, ILI9341_MAGENTA));    Serial.print(F("Circles (outline)        "));    Serial.println(testCircles(10, ILI9341_WHITE));    delay(500);    Serial.print(F("Triangles (outline)      "));    Serial.println(testTriangles());    delay(500);    Serial.print(F("Triangles (filled)       "));    Serial.println(testFilledTriangles());    delay(500);    Serial.print(F("Rounded rects (outline)  "));    Serial.println(testRoundRects());    delay(500);    Serial.print(F("Rounded rects (filled)   "));    Serial.println(testFilledRoundRects());    delay(500);    Serial.println(F("Done!"));}void loop(void){    for (uint8_t rotation = 0; rotation < 4; rotation++)    {        tft.setRotation(rotation);        testText();        delay(1000);    }}unsigned long testFillScreen(){    unsigned long start = micros();    tft.fillScreen(ILI9341_BLACK);    yield();    tft.fillScreen(ILI9341_RED);    yield();    tft.fillScreen(ILI9341_GREEN);    yield();    tft.fillScreen(ILI9341_BLUE);    yield();    tft.fillScreen(ILI9341_BLACK);    yield();    return micros() - start;}unsigned long testText(){    tft.fillScreen(ILI9341_BLACK);    unsigned long start = micros();    tft.setCursor(0, 0);    tft.setTextColor(ILI9341_WHITE);    tft.setTextSize(1);    tft.println("Hello World!");    tft.setTextColor(ILI9341_YELLOW);    tft.setTextSize(2);    tft.println(1234.56);    tft.setTextColor(ILI9341_RED);    tft.setTextSize(3);    tft.println(0xDEADBEEF, HEX);    tft.println();    tft.setTextColor(ILI9341_GREEN);    tft.setTextSize(5);    tft.println("Groop");    tft.setTextSize(2);    tft.println("I implore thee,");    tft.setTextSize(1);    tft.println("my foonting turlingdromes.");    tft.println("And hooptiously drangle me");    tft.println("with crinkly bindlewurdles,");    tft.println("Or I will rend thee");    tft.println("in the gobberwarts");    tft.println("with my blurglecruncheon,");    tft.println("see if I don't!");    return micros() - start;}unsigned long testLines(uint16_t color){    unsigned long start, t;    int x1, y1, x2, y2,        w = tft.width(),        h = tft.height();    tft.fillScreen(ILI9341_BLACK);    yield();    x1 = y1 = 0;    y2 = h - 1;    start = micros();    for (x2 = 0; x2 < w; x2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    x2 = w - 1;    for (y2 = 0; y2 < h; y2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    t = micros() - start; // fillScreen doesn't count against timing    yield();    tft.fillScreen(ILI9341_BLACK);    yield();    x1 = w - 1;    y1 = 0;    y2 = h - 1;    start = micros();    for (x2 = 0; x2 < w; x2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    x2 = 0;    for (y2 = 0; y2 < h; y2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    t += micros() - start;    yield();    tft.fillScreen(ILI9341_BLACK);    yield();    x1 = 0;    y1 = h - 1;    y2 = 0;    start = micros();    for (x2 = 0; x2 < w; x2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    x2 = w - 1;    for (y2 = 0; y2 < h; y2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    t += micros() - start;    yield();    tft.fillScreen(ILI9341_BLACK);    yield();    x1 = w - 1;    y1 = h - 1;    y2 = 0;    start = micros();    for (x2 = 0; x2 < w; x2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    x2 = 0;    for (y2 = 0; y2 < h; y2 += 6)        tft.drawLine(x1, y1, x2, y2, color);    yield();    return micros() - start;}unsigned long testFastLines(uint16_t color1, uint16_t color2){    unsigned long start;    int x, y, w = tft.width(), h = tft.height();    tft.fillScreen(ILI9341_BLACK);    start = micros();    for (y = 0; y < h; y += 5)        tft.drawFastHLine(0, y, w, color1);    for (x = 0; x < w; x += 5)        tft.drawFastVLine(x, 0, h, color2);    return micros() - start;}unsigned long testRects(uint16_t color){    unsigned long start;    int n, i, i2,        cx = tft.width() / 2,        cy = tft.height() / 2;    tft.fillScreen(ILI9341_BLACK);    n = min(tft.width(), tft.height());    start = micros();    for (i = 2; i < n; i += 6)    {        i2 = i / 2;        tft.drawRect(cx - i2, cy - i2, i, i, color);    }    return micros() - start;}unsigned long testFilledRects(uint16_t color1, uint16_t color2){    unsigned long start, t = 0;    int n, i, i2,        cx = tft.width() / 2 - 1,        cy = tft.height() / 2 - 1;    tft.fillScreen(ILI9341_BLACK);    n = min(tft.width(), tft.height());    for (i = n; i > 0; i -= 6)    {        i2 = i / 2;        start = micros();        tft.fillRect(cx - i2, cy - i2, i, i, color1);        t += micros() - start;        // Outlines are not included in timing results        tft.drawRect(cx - i2, cy - i2, i, i, color2);        yield();    }    return t;}unsigned long testFilledCircles(uint8_t radius, uint16_t color){    unsigned long start;    int x, y, w = tft.width(), h = tft.height(), r2 = radius * 2;    tft.fillScreen(ILI9341_BLACK);    start = micros();    for (x = radius; x < w; x += r2)    {        for (y = radius; y < h; y += r2)        {            tft.fillCircle(x, y, radius, color);        }    }    return micros() - start;}unsigned long testCircles(uint8_t radius, uint16_t color){    unsigned long start;    int x, y, r2 = radius * 2,              w = tft.width() + radius,              h = tft.height() + radius;    // Screen is not cleared for this one -- this is    // intentional and does not affect the reported time.    start = micros();    for (x = 0; x < w; x += r2)    {        for (y = 0; y < h; y += r2)        {            tft.drawCircle(x, y, radius, color);        }    }    return micros() - start;}unsigned long testTriangles(){    unsigned long start;    int n, i, cx = tft.width() / 2 - 1,              cy = tft.height() / 2 - 1;    tft.fillScreen(ILI9341_BLACK);    n = min(cx, cy);    start = micros();    for (i = 0; i < n; i += 5)    {        tft.drawTriangle(            cx, cy - i,     // peak            cx - i, cy + i, // bottom left            cx + i, cy + i, // bottom right            tft.color565(i, i, i));    }    return micros() - start;}unsigned long testFilledTriangles(){    unsigned long start, t = 0;    int i, cx = tft.width() / 2 - 1,           cy = tft.height() / 2 - 1;    tft.fillScreen(ILI9341_BLACK);    start = micros();    for (i = min(cx, cy); i > 10; i -= 5)    {        start = micros();        tft.fillTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,                         tft.color565(0, i * 10, i * 10));        t += micros() - start;        tft.drawTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,                         tft.color565(i * 10, i * 10, 0));        yield();    }    return t;}unsigned long testRoundRects(){    unsigned long start;    int w, i, i2,        cx = tft.width() / 2 - 1,        cy = tft.height() / 2 - 1;    tft.fillScreen(ILI9341_BLACK);    w = min(tft.width(), tft.height());    start = micros();    for (i = 0; i < w; i += 6)    {        i2 = i / 2;        tft.drawRoundRect(cx - i2, cy - i2, i, i, i / 8, tft.color565(i, 0, 0));    }    return micros() - start;}unsigned long testFilledRoundRects(){    unsigned long start;    int i, i2,        cx = tft.width() / 2 - 1,        cy = tft.height() / 2 - 1;    tft.fillScreen(ILI9341_BLACK);    start = micros();    for (i = min(tft.width(), tft.height()); i > 20; i -= 6)    {        i2 = i / 2;        tft.fillRoundRect(cx - i2, cy - i2, i, i, i / 8, tft.color565(0, i, 0));        yield();    }    return micros() - start;}

Upon running this you should be able to get the following output

gif of the final code running on the setup project.

For those who are running this with a hardware SPI or something that looks like

#define TFT_CS   7
#define TFT_DC   2
#define TFT_MOSI 6
#define TFT_CLK  4
#define TFT_RST  1
#define TFT_MISO 5

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_MOSI, TFT_CLK, TFT_RST, TFT_MISO);

Using hardware SPI, incredibly slow. For more details visit https://github.com/adafruit/Adafruit_ILI9341/issues/65 This will yield incredibly slow results. This is called out in an open issue https://github.com/adafruit/Adafruit_ILI9341/issues/65 and was originally the most frustrating part about trying to get the esp32-c3-32s working with an ILI9341 TFT screen. After I made the changes to use a software SPI it was incredibly fast.

#define TFT_CS   7
#define TFT_DC   2
#define TFT_RST  1

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

This is using a software SPI which is way faster than hardware SPI.

• ESP32
• esp32-c3
• ILI9341