# USB Keyboard with the Waveshare ESP32-S3-Zero

The `keyboard.ino` sketch registers the ESP32-S3-Zero as a USB HID keyboard.
After an initial delay of two seconds, it types `Hello Creat0r ` once every
second. The keystrokes go to the currently focused window; open an empty
text editor window to try it out.

## Prerequisites

- `arduino-cli` and `esptool` available on your `PATH`
- Espressif's `esp32:esp32` Arduino board package
- GNU Make for the Makefile commands
- A USB data cable and access to the board's serial port

The local development environment has Arduino CLI 1.5.1, the `esp32:esp32`
board package 3.3.12, and esptool 5.3.1 installed. The sketch uses the USB
libraries included in the ESP32 board package; no additional Arduino
libraries are required.

Run all commands below from the `keyboard` project directory.

## Compile Manually

```sh
arduino-cli compile --fqbn "esp32:esp32:esp32s3:USBMode=default,CDCOnBoot=default,FlashSize=4M,PartitionScheme=default" --output-dir build .
```

The board configuration targets the ESP32-S3 with 4 MB of flash and the USB
and partition settings shown above. Output files are saved in `build/`.
The merged flash image `build/keyboard.ino.merged.bin` is used for flashing.

## Flash Manually

Connect the board via USB and specify the appropriate port. The port used
previously was `/dev/ttyACM1`:

```sh
esptool --chip esp32s3 --port /dev/ttyACM1 --baud 460800 write-flash 0x0 build/keyboard.ino.merged.bin
```

The merged image is written starting at address `0x0`. If your device has a
different name, adjust the value after `--port`.

## Compile and Flash with Make

Compile only:

```sh
make compile
```

Compile and then flash:

```sh
make flash
```

Running `make` without a target is equivalent to `make compile`. The `flash`
target runs `compile` first and only flashes if compilation succeeds.

You can override the port and baud rate when running Make:

```sh
make flash PORT=/dev/ttyACM0 BAUD=460800
```

The default values match the manual commands. You can also customize
`ARDUINO_CLI`, `ESPTOOL`, `FQBN`, and `BUILD_DIR` using Make variables,
for example: `make compile BUILD_DIR=build-test`.

Delete generated binaries and other build files:

```sh
make clean
```

This removes the entire `build/` output directory. If you used a custom
directory, specify the same value: `make clean BUILD_DIR=build-test`.