jimgao1 / keyboard4

A 4 button RGB backlit keyboard.

About the 4 button keyboard

The 4 button keyboard is a 3D printed RGB mechanical keyboard, with a custom PCB. It can house 4 Cherry MX compatible RGB key switches.

More about it here (Insert link here).

This repository contains the API for writing a firmware for the 4 button keyboard, which runs on the ATmega32u4. It uses the TLC5940 chip to drive the 4 RGB LEDs. A few examples are provided.

This uses the LUFA USB library in order to establish the USB communication with the computer.

Compiling

git clone https://github.com/jackyliao123/keyboard4.git
cd keyboard4
make

After determining which serial port the device is attached to,

make upload port=[the serial port]

to upload the code onto the device.

Documentation

Header files

tlc5940.h

This header file contains function that can be used to interface with the TLC5940 LED driver chip.

void tlc5940_init(void)

Initializes the TLC5940.

void tlc5940_set_rgb(uint8_t led, uint16_t r, uint16_t g, uint16_t b)

Sets the RGB values of the led (0 - 3), to r, g, b values (0 - 4095). This does not immediately update the colours of the LEDs.

void tlc5940_update(void)

Sends the updated colour data to the TLC5940 chip, and therefore updating the colours of the LEDs.

usb.h

This header file contains function that can be used to interface with the USB host.

void usb_init(void)

Initializes USB.

void usb_run(void)

Updates the USB, and processes CDC packets received from the computer

bool usb_cdc_send(uint8_t *data, uint8_t len)

Send the first len bytes of data to the computer. len must not be greater than 16. Returns true when successful, returns false when otherwise.

FILE usb_cdc_stdout_create_stream(void)

Creates a stdio stream for CDC serial data going to the USB host. This can be used to remap stdout.

void usb_cdc_recv(uint8_t *data, uint8_t *len)

This is a function prototype, and it is called whenever data has been received on the USB serial console. The first len bytes of data represents the data that was received from the USB host.

void usb_keyboard_update_led(uint8_t led)

This is a function prototype, and it is called wheneter an update regarding the state of the LEDs on the keyboard is received. (e.g. Caps Lock led state change) led is a mask of all the LEDs.

void usb_keyboard_key_down(uint8_t key)

Sends a USB HID report, pressing down key.

void usb_keyboard_key_up(uint8_t key)

Sends a USB HID report, releasing key.

void usb_keyboard_modifier_down(uint8_t modifier)

Sends a USB HID report, pressing down the modifier key.

void usb_keyboard_modifier_up(uint8_t modifier)

Sends a USB HID report, releasing the modifier key.

void usb_mouse_button_down(uint8_t button)

Sends a USB HID report, pressing down the button on the mouse.

void usb_mouse_button_up(uint8_t button)

Sends a USB HID report, releasing the button on the mouse.

void usb_mouse_move(int16_t x, int16_t y)

Sends a USB HID report, moving the mouse by (+x, +y) in relative mode, and to (x, y) in absolute mode.

config.h

Contains configuration options for this device.

DEBOUNCE_TIMEOUT

The number of microseconds a key should be disabled for, when a state change occurs, in order to accomplish debouncing.

MOUSE_MIN_AXIS

To be documented

MOUSE_MAX_AXIS

To be documented

MOUSE_MIN_PHYS

To be documented

MOUSE_MAX_PHYS

To be documented

MOUSE_ABS

A boolean. true if this device should report itself as an absolute pointing device (touchscreen), false otherwise (mouse).

USB_VID

The USB manufacturer ID that this device should report itself as.

USB_PID

The USB product ID that this device should report itself as.

USB_MANUFACTURER

The USB manufacturer string this device should report.

USB_PRODUCT

The USB product string that this device should report.

USB_SERIAL

The USB serial string that this device should report. If not present, the internal serial will be used.

util.h

Contains utilities for writing code for the device

void util_init(void)

Initializes ports and timers.

uint32_t util_micros(void)

Returns the number of microseconds elapsed since util_init().

void util_key_poll(void)

Polls for changes in the keys, and call util_key_update when such event happens.

void util_key_update(uint8_t key, uint8_t state)

This is a function prototype, and it is called whenever key changes state to state. state is 0 when key is released, and 1 when key is pressed.