https://github.com/wokwi/led-recorder
export LED animation from Wokwi into JSON Lines / binary files
https://github.com/wokwi/led-recorder
Last synced: about 2 months ago
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export LED animation from Wokwi into JSON Lines / binary files
- Host: GitHub
- URL: https://github.com/wokwi/led-recorder
- Owner: wokwi
- License: mit
- Created: 2021-03-24T10:38:23.000Z (about 4 years ago)
- Default Branch: gh-pages
- Last Pushed: 2021-03-27T11:18:51.000Z (about 4 years ago)
- Last Synced: 2025-01-16T14:52:38.621Z (3 months ago)
- Language: JavaScript
- Size: 9.77 KB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# LED Animation Recorder
Use this tool to export LED animation from Wokwi into [NDJSON](http://ndjson.org/) / [JSON Lines](https://jsonlines.org/) or binary files.
## Usage
Add the following part to your [diagram.json file](https://docs.wokwi.com/diagram-format), specifying the number of pixels in the strip/matrix:
```json
{
"type": "wokwi-neopixel-strip",
"id": "neopixels",
"attrs": { "pixels": "3" }
}
```
Note that the part id _must_ be `neopixels` for the recorder to work.
and then add a customView:
```json
"customView": "https://wokwi.github.io/led-recorder",
```
Example for a complete diagram.json file:
```json
{
"version": 1,
"author": "Uri Shaked",
"editor": "wokwi",
"customView": "https://wokwi.github.io/led-recorder",
"parts": [
{
"type": "wokwi-arduino-uno",
"id": "uno",
"top": 0,
"left": 150
},
{
"type": "wokwi-neopixel-strip",
"id": "neopixels",
"attrs": { "pixels": "3" }
}
],
"connections": [["uno:3", "neopixels:DIN", ""]]
}
```
## File format (NDJSON / JSON Lines)
Each line is a JSON object. The first line is a header line, which contains information about the recording. The animation frames are encoded in the subsequent lines, one line per frame.
The header contains the following fields:
| Name | Type | Description |
| --------- | ------ | ------------------------------------ |
| magic | string | "WokwiLED" |
| version | number | Always 1 |
| pixels | number | Number of pixels per frame |
| frameRate | number | Frames per second (usually 30 or 60) |
The frames contain the following fields:
| Name | Type | Description |
| --------- | ------ | --------------------------------------- |
| frame | number | Frame index, starting from 0 |
| leds | array | LED values: |
| leds[n].r | number | The red value of pixel `n` |
| leds[n].g | number | The green value of pixel `n` |
| leds[n].b | number | The blue value of pixel `n` |
| leds[n].a | number | The alpha value of pixel `n` (optional) |
Pixel values (r, g, b, a) are integer values between 0 and 255.
Example:
```json
{ "magic": "WokwiLED", "version": 1, "pixels": 3, "frameRate": 30 }
{ "frame": 0, "leds": [ {"r":255,"g":0,"b":0}, {"r":0,"g":0,"b":0}, {"r":0,"g":0,"b":0} ] }
{ "frame": 1, "leds": [ {"r":0,"g":0,"b":0}, {"r":0,"g":255,"b":0}, {"r":0,"g":0,"b":0} ] }
{ "frame": 2, "leds": [ {"r":0,"g":0,"b":0}, {"r":0,"g":0,"b":0}, {"r":0,"g":0,"b":255} ] }
{ "frame": 3, "leds": [ {"r":0,"g":0,"b":0}, {"r":0,"g":255,"b":0}, {"r":0,"g":0,"b":0} ] }
...
```
## File format (binary)
The file begins with a 32 byte header, followed by animation frames. All values are little endian.
The header contains the following fields:
| Offset | Bytes | Name | Description |
| ------ | ----- | ------- | --------------------------- |
| 0 | 8 | magic | "WokwiLED" |
| 8 | 4 | version | Always 1 |
| 12 | 4 | nframes | Number of frames |
| 16 | 4 | npixels | Number of pixels per frame |
| 20 | 4 | fps | Number of frames per second |
| 24 | 8 | | Reserved, set to 0 |
Each frame is an array of `npixels` DWORDs. Each element is in the following
format: `0x00GGRRBB`, where `GG` indicatates the green value, `RR` indicates
the red value, and `BB` (the lowest byte) indicates the blue value.
## License
Copyright (C) 2021 Uri Shaked. Released under the [MIT license](LICENSE).