A complete
CW Keyer
in your hand.

Clone the repository

git clone https://github.com/mfalco1959/IW1RMM_CW_Encoder.git

Or download the ZIP from GitHub and extract it.

Install the ESP32 board package

In Arduino IDE: File → Preferences → Additional boards manager URLs, add:

https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

Then Tools → Board → Boards Manager → search esp32 → install esp32 by Espressif Systems.

⚠ Tested with ESP32 Arduino Core 3.x. The BLE and DacESP32 libraries require Core 3.x — do not use 2.x.

Install required libraries

In Arduino IDE: Sketch → Include Library → Manage Libraries

Configure TFT_eSPI

Copy docs/User_Setup_example.h to your TFT_eSPI library folder (typically Documents/Arduino/libraries/TFT_eSPI/) and rename it User_Setup.h, replacing the existing file. Key settings for the CYD:

#define ILI9341_DRIVER
#define TFT_MISO  12
#define TFT_MOSI  13
#define TFT_SCLK  14
#define TFT_CS    15
#define TFT_DC     2
#define TFT_RST   -1
#define TOUCH_CS  -1
#define SPI_FREQUENCY  40000000

⚠ Make sure TFT_MISO 12 is defined and NOT commented out — the SD card will fail otherwise.

Copy lv_conf.h

Copy include/lv_conf.h from this repository into the sketch folder (same directory as IW1RMM_CW_Encoder.ino). This file enables the fonts used by the UI — without it the sketch will not compile.

Arduino IDE upload settings

Select board and configure upload options exactly as shown:

⚠ DIO + 40 MHz are mandatory. CYD boards often use ZBIT ZB25VQ32 flash chips that are sensitive to faster or QIO settings — using QIO or 80 MHz will cause upload failures or boot loops.

💡 Upload speed: 115200 baud is the safe recommended value. If you plan to upload only occasionally, you may try increasing the speed (e.g. 460800 or 921600) to reduce upload time, but stability depends on your USB cable and PC driver.

Open the sketch and upload

Open IW1RMM_CW_Encoder/IW1RMM_CW_Encoder.ino in Arduino IDE. Connect the CYD via USB-C. Select the correct COM port under Tools → Port. Click Upload.

On first boot, the touch calibration wizard will start automatically. Follow the on-screen instructions to touch each of the 4 corner crosshairs. Calibration is saved permanently — it will not repeat on subsequent boots.

Alternative: flash precompiled binary with esptool

If you prefer not to use Arduino IDE, flash the precompiled .bin directly:

python -m esptool --chip esp32 --port COM4 --baud 115200 \
  --before default-reset --after hard-reset \
  write-flash -z --flash-mode dio --flash-freq 40m \
  --flash-size detect 0x10000 IW1RMM_CW_Encoder_v714.bin

Replace COM4 with your actual port (Linux: /dev/ttyUSB0, Mac: /dev/cu.usbserial-*).