This project used for installing on Raspberry Pi.
LED Strip is connected to Raspberry Pi GPIO pins.
This program opens TCP server on port 3384 and waits for plain TCP packets, created as described here:
- Basic color change
- Protocol parser with all needed checks
- Setting up pigpio and setting color to pins
- Use config file
- Some basic animations support
- Get current color support in protocol
- OpenRGB SDK support (connect to server, get devices, choose where to set and set colors on them too)
- Use config file from home directory
- systemd service
- brightness support (?)
LED PROTOCOL v4
Simply contains HEADER + HMAC-SHA-256 + PAYLOAD
Currently max buffer size: 8+8+1+1+32+1+1+1+1+1 = 55 bytes.
| Version | Description |
|---|---|
| v1, 0x1 | Initial release, support of changing color |
| v2, 0x2 | Added plain changing from current color to new |
| v3, 0x3 | Added support of getting current color |
| v4, 0x4 | Added support of animations (would be added more by new OPs) |
| Name | Size | Version | Description |
|---|---|---|---|
| timestamp | 8 bytes, unsigned | 1 | Timestamp of current time |
| nonce | 8 bytes, unsigned | 1 | Random data |
| version | 1 byte, unsigned | 1 | Used version of protocol |
| OP | 1 byte, unsigned | 3 | Operational code |
Must be generated with SHA-256 algorithm with using shared_secret which writed in both client and server and data must be used header+payload:
HMAC(SHA-256, shared_secret, header + payload)
| Value | Name | Description |
|---|---|---|
| 0 | LED_SET_COLOR | Set RGB color, described in PAYLOAD |
| 1 | LED_GET_CURRENT_COLOR | Request led-server current LEDs color |
| 2 | ANIM_SET_FADE | Start FADE animation |
| Name | Size | Version | Description |
|---|---|---|---|
| RED color | 1 byte, 8 bits, unsigned | 1 | RED color value |
| GREEN color | 1 byte, 8 bits, unsigned | 1 | GREEN color value |
| BLUE color | 1 byte, 8 bits, unsigned | 1 | BLUE color value |
| Duration | 1 byte, 8 bits, unsigned | 2 | Duration in seconds of changing color from current to new |
| Speed | 1 byte, 8 bits, unsigned | 4 | Speed of animation, from 0 to 255, conv. units |
Request size: 55 bytes (HEADER + HMAC + PAYLOAD)
Response size: 0 bytes (no response)
Sets up RGB color, defined in PAYLOAD to GPIO pins.
Request size: 50 bytes (HEADER + HMAC without PAYLOAD)
Response size: 11 bytes
The response contains timestamp when response package created (8 bytes) and RGB values (3 bytes summary respectively).
Request size: 55 bytes (HEADER + HMAC + PAYLOAD)
Response size: 0 bytes (no response)
Starts FADE animation. To PAYLOAD must be added Speed field as described at PAYLOAD Structure
- Generate Timestamp and Nonce
- Timestamp: Use Unix time (seconds since January 1, 1970). (64-bit)
- Nonce: Generate a random number to ensure each request is unique. (64-bit)
- Prepare the Payload
- The payload contains the actual data to be sent to the server, such as the color value.
- Generate the HMAC
- Pack package and send to server
- Receive and Parse the Request
- Receive the header, HMAC, and payload.
- Verify Timestamp and Nonce
- Ensure the timestamp is recent and the nonce hasn’t been used before.
- Recompute the HMAC
- Data to HMAC: Concatenate the header and payload.
- HMAC Calculation: Recompute the HMAC using the shared secret.
- Compare the recomputed HMAC with the received HMAC. If they match, proceed; if not, reject the request.
- Process the Request
- Process the color value from the payload.
- RPi with running
pigpiod libssl-devlibconfig
git clone --recursive https://github.com/PolisanTheEasyNick/led-servercd led-servermkdir buildcd buildcmake ..make./led-server