pulseplot/lib/broadlinkrm.js

Pulse data viewer JS library

/**
    @file BroadlinkRM JS.

    @author Christian W. Zuckschwerdt <zany@triq.net>
    @copyright Christian W. Zuckschwerdt, 2025
    @license
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 2 of the License, or
    (at your option) any later version.
*/

export class BroadlinkRM {
    static isBroadlinkRM(line) {
        try {
            bin = atob(line)
        } catch (error) {
            return false // Not base64
        }

        if (bin.length < 4) {
            return false // Invalid data header
        }

        const codeType = bin.charCodeAt(0)
        if (codeType == 0xb2 || codeType == 0xb1) {
            return true // 433 MHz
        } else if (codeType == 0xd7) {
            return true // 315 MHz
        } else if (codeType == 0x26) {
            return false // IR code
        } else {
            return false // Unknown code type
        }
    }

    static decodeData(line) {
        let data = {
            pulses: [],
            frequency: 0,
            repeats: 0,
            errors: "",
        }

        let bin = ""
        try {
            bin = atob(line)
        } catch (error) {
            data.errors = 'Invalid Base64'
            console.warn(data.errors)
            return data
        }

        if (bin.length < 4) {
            data.errors = 'Invalid data header'
            console.warn(data.errors)
            return data
        }

        const codeType = bin.charCodeAt(0)
        if (codeType == 0xb2 || codeType == 0xb1) {
            data.frequency = 433920000 // 433 MHz
        } else if (codeType == 0xd7) {
            data.frequency = 315000000 // 315 MHz
        } else if (codeType == 0x26 /* IR code */) {
            data.errors = 'Unsupported code type'
            console.warn(data.errors, codeType)
            return data
        } else {
            data.errors = `Invalid code type (${codeType.toString(16)})`
            console.warn(data.errors, codeType)
            return data
        }

        data.repeats = bin.charCodeAt(1)

        let dataLen = bin.charCodeAt(2) | (bin.charCodeAt(3) << 8)  // big endian
        if (dataLen + 2 != bin.length) {
            data.errors = 'Code length mismatch'
            console.warn(data.errors)
        }

        for (let i = 4; i < bin.length; i++) {
            let pulse = bin.charCodeAt(i);
            if (pulse == 0) {
                pulse = bin.charCodeAt(++i) | (bin.charCodeAt(++i) << 8) // big endian
            }
            data.pulses.push(pulse)
        }

        return data
    }
}