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Built-in project · Cheap Yellow Display (ESP32-2432S028R)

CYD hello

The Cheap Yellow Display writes on its own 2.8 inch screen with TFT_eSPI, set up as the board is wired, and cycles its RGB LED. The whole build, a Cheap Yellow Display, runs here in your browser on the firmware below; open it in the editor to change the wiring or the code and run it again.

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The parts retail for about $14. On Mokxi they're free.

CYD hello · Cheap Yellow Display (ESP32-2432S028R)live0.000 s 0.00x
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The circuit itself, running here on the simulator. Press what can be pressed; click anything else to open it in the editor.

The code

The firmware exactly as the editor opens it. Change a line there and press Run: it compiles in the browser.

sketch.ino · Cheap Yellow Display (ESP32-2432S028R)
// Hello: the CYD's screen through TFT_eSPI, with the board's setup built in,
// and its RGB LED, each color lit LOW.

#include <TFT_eSPI.h>

TFT_eSPI tft = TFT_eSPI();

const int kRed = 4;
const int kGreen = 16;
const int kBlue = 17;

void setup()
{
    Serial.begin(115200);
    pinMode(kRed, OUTPUT);
    pinMode(kGreen, OUTPUT);
    pinMode(kBlue, OUTPUT);

    tft.init();
    tft.setRotation(1); // landscape, the way the board is usually held
    tft.fillScreen(TFT_BLACK);
    tft.setTextColor(TFT_YELLOW, TFT_BLACK);
    tft.drawCentreString("Hello, CYD!", 160, 30, 4);
    tft.setTextColor(TFT_WHITE, TFT_BLACK);
    tft.drawCentreString("ESP32-2432S028R", 160, 70, 2);
    tft.fillRect(40, 120, 80, 60, TFT_RED);
    tft.fillRect(120, 120, 80, 60, TFT_GREEN);
    tft.fillRect(200, 120, 80, 60, TFT_BLUE);
    Serial.println("Screen drawn.");
}

void loop()
{
    // Red, green, blue, each lit LOW in turn.
    const int pins[3] = {kRed, kGreen, kBlue};
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) digitalWrite(pins[j], j == i ? LOW : HIGH);
        tft.fillRect(40 + i * 80, 190, 80, 8, TFT_WHITE);
        delay(400);
        tft.fillRect(40 + i * 80, 190, 80, 8, TFT_BLACK);
    }
}

Parts list

1 part, plus the jumper wires. They retail for about $14; on Mokxi they're free.

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