Fongwah-qz.js

// Code backup 2020-02-27
// Fongwah UHF Reader WRD-130-U1
// QZ Tray 2.1.0

// Work in progress, not yet functional
function scanRFID() {
    let vid = "0x0e6a";
    let pid = "0x0317";
    let usage = "0x0c";

    // Toggle automatic scanning option
    var autoScan = false;
    var scanTime = 0x01; // x10ms (ignored if autoScan is off)
    var sameCard = 0x01; // x100mx (ignored if autoScan is off)

    // Toggle keyboard emulation
    var kbdEmu = false;

    // Configure read sensitivity
    var dBm = -2;

    // Frequency range
    var range = {
        us: 0x31, // 902-928 Mhz
        tw: 0x32, // 922-928 Mhz
        cn: 0x33, // 920-925 Mhz
        cn2: 0x34, // 840-845 Mhz
        eu: 0x35, // 865-868 Mhz
        jp: 0x36, // 916-921 Mhz
        kr: 0x37, // 917-921 Mhz 
        vn: 0x38, // 918-923 Mhz
        eu2: 0x39, // 916-920 Mhz
        in: 0x41 // 865-867 Mhz
    }
    var devRange = range.us;
            

    qz.hid.claimDevice({
        vendorId: vid,
        productId: pid,
        usagePage: usage,
    }).then(function() {
        // Set jurisdicational radio frequency mode (e.g. FCC complaince)
        return qz.hid.sendData({
            vendorId: vid,
            productId: pid,
            usagePage: usage,
            endpoint: 0x08,
            data: [0x02, 0x41, 0x4E, 0x35, 0x2C, 0x30, devRange]
        });
    }).then(function() {
        // Set USB mode options (for toggling on/off keyboard emulation)
        return qz.hid.sendData({
            vendorId: vid,
            productId: pid,
            usagePage: usage,
            endpoint: 0x08,
            data: [0x02, 0x92, 0x00, 0x02, kbdEmu ? 0x01 : 0x00, 0x05]
        });
    }).then(function() {
        // Set auto-read options (for toggling on/off auto-scan feature)
        console.log("Setting auto read to ", autoScan);
        return qz.hid.sendData({
            vendorId: vid,
            productId: pid,
            usagePage: usage,
            endpoint: 0x08,
            data: [0x02, 0x92, 0x02, 0x04, autoScan ? 0xC3 : 0x43, scanTime, sameCard, 0x00 ]
        });
    }).then(function() {
        //
        // FIXME: This isn't working
        //
        // Set distance/sensitivy option
        // - Valid range: -2dBm - 27dBm
        //   -2dBm = 0x30 0x30
        //   27dBm = 0x31 0x44

        // Calculate bits (most significant, least significant)
        // **WARNING** Magic counting to follow:
        // 1. MSB incriments when LSB hits 0x46 hex
        // 2. Counting is done using decimal, BUT...
        // 3. Decimal is strangly passed in hex format
        var msb = parseInt(30 + Math.floor(((dBm + 2) + 30)/46), 16);
        var lsb = parseInt(30 + ((dBm + 2) % 46), 16);
        console.log("Setting power level to", dBm + "dBm = ", "MSB:", "0x" + msb.toString(16), "LSB:", "0x" + lsb.toString(16));
        return qz.hid.sendData({
            vendorId: vid,
            productId: pid,
            usagePage: usage,
            endpoint: 0x08,
            data: [0x02, 0x41, 0x4E, 0x31, 0x2C, msb, lsb]
        })
    }).then(function() {
        // Blink lights and beeper
        console.log("Beeping and blinking light...")
        return qz.hid.sendData({
            vendorId: vid,
            productId: pid,
            usagePage: usage,
            endpoint: 0x04, // Note: Beep uses a different endpoint
            data: [0x02, 0x91, 0x09, 0x32],
        });
    }).then(function() {
        // read current etag
        console.log("Asking to read eTag")
        return qz.hid.sendData({
            vendorId: vid,
            productId: pid,
            usagePage: usage,
            endpoint: 0x08,
            data: [0x02, 0x41, 0x52, 0x31, 0x2C, 0x32, 0x2C, 0x34],
        });
    }).then(function() {
        // repeat read a few times to ensure we get the latest values
        var chain = [];
        for(var i = 0; i < 5; i++) {
            var link = function() {
                return qz.hid.readData({
                    vendorId: vid,
                    productId: pid,
                    usagePage: usage,
                    responseSize: 32
                }).then(function(read) {
                    console.log(read);
					parseHex(read);
                    return new Promise(resolve => setTimeout(resolve, 500));
                });
            };

            chain.push(link);
        }

        //build and execute the promise loop
        var firstLink = Promise.resolve();
        var lastLink = null;
        chain.reduce(function(sequence, link) {
            lastLink = sequence.then(link);
            return lastLink;
        }, firstLink);

        //cleanup device
        lastLink.then(function() {
            qz.hid.releaseDevice({
                vendorId: vid,
                productId: pid,
                usagePage: usage
            });
        }).catch(function(err) {
            console.error(err);
        });
    }).catch(function(e) {
        console.error(e);
    });
}

//
// FIXME: This isn't working
//
function parseHex(data) {
	var parsed = "";
	for(var i in data) parsed += String.fromCharCode(parseInt(data[i], 16));
	var start = parsed.indexOf("R");
	var length = 24;
	if(start == 4 && parsed.length - (start + 1) >= length) {
		console.log(parsed.substring(start + 1, start + 1 + length));
	} else {
		console.warn("Couldn't parse data as RFID tag", parsed);
	}
}