CORE-ESP32C3 development board

The CORE-ESP32 core board is based on Espressif ESP32-C3 SoC that fits good on a breadboard and has the option for a LCD + digital joystick shield on top. The ESP32-C3 variant is supported by the HomeDing library.

core-esp32c3 board

The CORE-ESP32 core board is based on Espressif ESP32-C3 SoC.

ESP32-C3 processor
4 MByte Flash memory in DIO mode
This is a small board 21mm * 51mm that fits good on breadboards.
2 LEDs
Reset button
BOOT button
2.4G PCB onboard antenna

The CORE-ESP32 board is labeled with luatos.com

Arduino Board Configuration

There are 2 main board variants that differ in the implementation of the USB port.

One variant has an onboard CH343 USB to serial adapter.
Second variant exposes the USB port of the ESP32-C3 directly.

The ESP32C3 Dev Module (esp32) can be used with the following settings:

JTAG Adapter: Disbled
USB CDC On Boot: Disbled for version with CH343 USB adapter
USB CDC On Boot: Enabled for version with direct USB connection
Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS)
CPU Frequency: 160MHz
Flash Mode: DIO
Flash Frequency: 80 MHz
Flash Size: 4MByte (32Mbit)
Upload Speed: 921600
Core Debug Level: None
Erase All Flash: Disabled

Main Board components

The following components are already on-board:

4MB single channel SPI FLASH with 2 data lines.
Important: Be sure to flash in DIO mode. QIO doesn’t work.
GPIO12: LED D4 (right to USB)
GPIO13: LED D5 (left to USB)
RST: RST Button
GPIO09: Boot Button

The SPI bus is available and also used by the LCD display.

GPIO02: SPI-SCK
GPIO03: SPI-MOSI
GPIO10: SPI-MISO
GPIO07: SPI-CS

The I2C bus is mentioned in the manual but not labeled on board:

GPIO04: I2C-SDA
GPIO05: I2C-SCL

Board configuration

The following env.json configuration can be used for this board:

{
  "device": {
    "0": {
      "name": "corec3",
      "title": "CORE-ESP32C3",
      "description": "ESP32-C3 based dev board.",
      "button": "9",
      "led": "12",
      "i2c-scl": "5",
      "i2c-sda": "4"
    }
  },
  "digitalout": {
    "ledD4": { "pin": "12" },
    "ledD5": { "pin": "13" }
  }
}

LCD + Digital Joystick Shield

There is a TFT display and a digital joystick shield available that can be stacked upon the CPU board.

It offers a 0.96 inch display with 80*160 pixels and 262K Color based on the ST7735S driver chip. The background lightning is not adjustable and always on.

The Boot and Reset buttons are not reachable any more after mounting this board.

core-esp32c3 shield

key	GPIO pin
down	GPIO13
left	GPIO5
up	GPIO8
right	GPIO9
press	GPIO4

The down key conflicts with the on-board LED that must not used as digital output when the shield is used.

Shield configuration

The following configuration can be used for the Shield:

{
  "DisplayST7735": {
    "0": {
      "description": "Display",
      "loglevel": 2,
      "width": "80",
      "height": "160",
      "colOffset": 26,
      "rowOffset": 1,

      "busmode": "spi",
      "spiClk": 2,
      "spiMosi": 3,
      "resetPin": 10,
      "spiDC": 6,
      "spiCS": 7,
      "rotation": 270
    }
  },
  "digitalin": {
    "right": { "pin":  "9", "invert": "1", "pullup": 1 },
    "up":    { "pin":  "8", "invert": "1", "pullup": 1 },
    "left":  { "pin":  "5", "invert": "1", "pullup": 1 },
    "down":  { "pin": "13", "invert": "1", "pullup": 1 },
    "press": { "pin":  "4", "invert": "1", "pullup": 1 }
  }
}

Pictures

core-esp32c3 board with pins core-esp32c3 on breadboard