CYD ESP32-2424S012
ESP32-C3 board with 1.2" LCD - compact UI-ready board for smart devices, wearables, or sensor dashboards.
CYD ESP32-2424S012 Pinout
19 pins
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | - | 3V33.3V | power | - | 3.3V rail on the JST-SH 1.0mm UART programming connector (P1 pin 2) |
| 2 | - | GND | ground | - | Ground on the JST-SH 1.0mm UART programming connector (P1 pin 1) |
| 3 | 21 | TXIO21U0TXD | uart | uart | UART0 TX on the JST-SH programming connector (P1 pin 3); shared with the serial console |
| 4 | 20 | RXIO20U0RXD | uart | uart | UART0 RX on the JST-SH programming connector (P1 pin 4); shared with the serial console |
| 5 | 8 | IO8GPIO8 | strapping | pwm | Bare round test pad S1 printed IO8, beside the JST-SH connector (0 ohm link R3, 10k pull-up R14 to 3.3V); the only spare GPIO on the board, and a strapping pin that must stay high at reset |
| 6 | - | BAT+VBAT | power | - | 3.7V LiPo input on the JST 1.25mm battery connector (via IP5306) |
| 7 | - | GND | ground | - | Ground on the JST 1.25mm battery connector |
| 8 | 9 | IO9GPIO9BOOT | control | - | BOOT button (GPIO9, 10k pull-up); strapping pin - held low at reset it enters serial download mode. Usable as a button input afterwards |
| 9 | 6 | strapping | - | LCD SPI clock (SCK) on the GC9A01 display; not free | |
| 10 | 7 | strapping | - | LCD SPI data (MOSI) on the GC9A01 display; not free. The display has no MISO line | |
| 11 | 10 | safe | - | LCD chip select on the GC9A01 display; not free | |
| 12 | 2 | strapping | - | LCD data/command (DC) on the GC9A01 display; not free, and a strapping pin. The display's RESET is tied to the chip's EN, not to a GPIO | |
| 13 | 3 | safe | - | LCD backlight enable, switching the AO3402 MOSFET (Q2); HIGH turns the backlight on, PWM dims it | |
| 14 | 4 | strapping | - | Touch I2C SDA (4.7k pull-up) on the CST816D controller; not free | |
| 15 | 5 | strapping | - | Touch I2C SCL (4.7k pull-up) on the CST816D controller; not free | |
| 16 | 0 | safe | - | Touch interrupt (TP_INT) from the CST816D controller; not free | |
| 17 | 1 | safe | - | Touch reset (TP_RST) to the CST816D controller; not free | |
| 18 | 18 | uart | - | USB D- to the USB-C port; the C3's built-in USB Serial/JTAG, which is how the board is flashed | |
| 19 | 19 | uart | - | USB D+ to the USB-C port; the C3's built-in USB Serial/JTAG, which is how the board is flashed |
Fine - with a little care
4 pins · 4 things to knowTXGPIO21 UART0 TXD (default serial output) UART
Used as UART0 transmit (console/bootloader); repurposing may disable serial console output and printing
RXGPIO20 UART0 RXD (default serial input) UART
Used as UART0 receive (console/bootloader); repurposing may disable serial programming and debug logs
IO8 Bootstrapping pin (needs HIGH at reset); also gates ROM boot message printing (UART_PRINT_CONTROL efuse) Strapping
Must be held high during reset (if low, UART flashing/boot may not work)
IO9 Bootstrapping pin; selects boot mode (HIGH = SPI flash boot, LOW = UART download) Strapping
Controls boot mode on reset (HIGH for normal flash boot, LOW enters serial download mode)
Only if you know the tricks
11 pins · 3 things to knowGPIO6GPIO7GPIO10GPIO2GPIO3 Used by Display (GC9A01) onboard hardware
Wired to Display (GC9A01) on this board, which is soldered down. Driving it from your own code breaks that function.
- LCD SPI clock (SCK) on the GC9A01 display; not free
- LCD SPI data (MOSI) on the GC9A01 display; not free. The display has no MISO line
- LCD chip select on the GC9A01 display; not free
- LCD data/command (DC) on the GC9A01 display; not free, and a strapping pin. The display's RESET is tied to the chip's EN, not to a GPIO
- LCD backlight enable, switching the AO3402 MOSFET (Q2); HIGH turns the backlight on, PWM dims it
GPIO4GPIO5GPIO0GPIO1 Used by the touch controller (CST816D) onboard hardware
Wired to the touch controller (CST816D) on this board, which is soldered down. Driving it from your own code breaks that function.
- Touch I2C SDA (4.7k pull-up) on the CST816D controller; not free
- Touch I2C SCL (4.7k pull-up) on the CST816D controller; not free
- Touch interrupt (TP_INT) from the CST816D controller; not free
- Touch reset (TP_RST) to the CST816D controller; not free
GPIO18GPIO19 Used by the USB-C port (native USB Serial/JTAG) onboard hardware
Wired to the USB-C port (native USB Serial/JTAG) on this board, which is soldered down. Driving it from your own code breaks that function.
- USB D- to the USB-C port; the C3's built-in USB Serial/JTAG, which is how the board is flashed
- USB D+ to the USB-C port; the C3's built-in USB Serial/JTAG, which is how the board is flashed
The CYD ESP32-2424S012 breaks out 19 pins in total: 14 GPIO for your project, with 3V3, GND and BAT+ handling power.
Peripheral wiring is straightforward: TX/RX on GPIO21 and GPIO20 cover serial logging and flashing.
Beyond plain digital I/O you get PWM on 1 pins.
4 of the exposed pins carry boot-time or system duties on the ESP32-C3 (TX, RX, IO8 and 1 more) - check the guidance above before wiring anything to them.
Getting started
flash your first firmware in ~2 minutesBoard: ESP32C3 Dev Module USB CDC On Boot: Enabled Flash Size: 4MB (32Mb) Flash Mode: DIO Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS) Upload Speed: 921600
// toggle GPIO10 - wire an LED and resistor to it
void setup() {
pinMode(10, OUTPUT);
}
void loop() {
digitalWrite(10, HIGH); delay(500);
digitalWrite(10, LOW); delay(500);
}[env:cyd-esp32-2424s012]
platform = espressif32
board = esp32-c3-devkitm-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32-c3-devkitm-1 - or type it after board =.esp32:
board: esp32-c3-devkitm-1
variant: esp32c3
framework:
type: esp-idf
# blink - GPIO10
output:
- platform: gpio
pin: 10
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32-c3-devkitm-1 (same ids as PlatformIO).esptool.py --chip esp32c3 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x0 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Downloads
Free for non-commercial use, credit espboards.dev · License
Board illustration
The bare CYD ESP32-2424S012 board drawn to scale at 38.5 × 37 mm, with no pin labels on it. Made for slide decks, wiring diagrams and project write-ups where a photo is too busy. Take the scalable SVG for print or editing, the high-resolution PNG to drop straight in, or the transparent PNG when you need it with no background behind it.
Pinout diagram
Every pin on both sides of the board with its functions, drawn by ESPboards from the ESP32-C3 Series Datasheet v2.4 - the same sheet shown at the top of this page. The PNG is a high-resolution image for screens, the SVG is vector so it stays sharp at any size, and the PDF is laid out to print on A4 or Letter.
Yours to use, share and adapt for non-commercial work, as long as you credit espboards.dev - the full terms and ready-made credit lines are here.
Specifications
ESP32-C3 · 38.5 × 37 mm · vs other ESP32 chips →Dimensions
About this board
At 38.5 × 37 mm it's the smallest CYD board we've measured.
Inside sits the ESP32-C3 - a single-core RISC-V and the budget low-power pick. Sibling CYD boards cover the ESP32-S3 and ESP32, so you can change radios or horsepower without changing the footprint.
It's the only ESP32-C3 option in the CYD family.
The $20.00 price tag is typical for a CYD board.
Around the module: a Round TFT 1.28" 240x240 display with touch, battery charging (IP5306) via JST 1.25mm and Reset/Boot/Power buttons.
It flashes over native USB - no serial-converter driver needed, which isn't a given among CYD boards.
Where to buy
prices are typical street pricesResources
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