Need help connecting Fingerprint Scanner - TTL (GT-511C3) over UART Serial Comms

I cant really test it.. but i looked a bit at the index.js and saw i was testing a function for complete enrollment. A few minor changes i think and you should get it to work.

Try this as a replacement for the index.js

'use strict';

let GT511CXX = require('./gt511cxx.js');

GT511CXX.prototype.enroll = function(id) {
    let me = this,
        open = () => me.open(),
        start = () => me.enrollStart(id),
        capture = () => me.captureFinger(true),
        waitFinger = () => me.waitFinger(10000, false),
        waitReleaseFinger = () => me.waitFinger(10000, true),
        ledOn = () => me.switchLED(true),
        ledOff = () => me.switchLED(false),
        enroll1 = () => me.enroll1(),
        enroll2 = () => me.enroll2(),
        enroll3 = () => me.enroll3(),
        enrollDelay = () => new Promise(resolve => setTimeout(resolve, 500)),
        blinkDelay = () => new Promise(resolve => setTimeout(resolve, 100));

    return new Promise((resolve, reject) => {
        let errorHandler = (err) => { ledOff(); reject(err); },
            successHandler = () => { console.log('enroll success'); resolve(); };

        open()
            .then(ledOn)
            .then(() => console.log('press finger'))
            .then(waitFinger)
            .then(start)
            .then(capture)
            .then(enroll1)
            .then(() => console.log('enroll 1 done'))
            .then(ledOff)
            .then(blinkDelay)
            .then(ledOn)
            .then(() => console.log('release finger'))
            .then(waitReleaseFinger)
        .then(enrollDelay)
            .then(() => console.log('press finger'))
            .then(waitFinger)
            .then(capture)
            .then(enroll2)
            .then(() => console.log('enroll 2 done'))
            .then(ledOff)
            .then(blinkDelay)
            .then(ledOn)
            .then(() => console.log('release finger'))
            .then(waitReleaseFinger)
        .then(enrollDelay)
            .then(() => console.log('press finger'))
            .then(waitFinger)
            .then(capture)
            .then(enroll3)
            .then(() => console.log('enroll 3 done'))
            .then(ledOff)
        .then(successHandler)
        .catch(errorHandler);
    });
};

let fps = new GT511CXX(GT511CXX.Devices.GT511C1R, Serial1);

fps.enroll(0); // ID 0 means first storage slot .. slot has to be empty

The enrollment function itself shows a lot of the usage i had in mind.
It is more a series of module calls then a module function itself.. but the
complete enrollment process was so tedious that i wanted to provide a solution with
the module i guess.

Btw. pretty much all of the code is based on the documents i found here:
http://www.adh-tech.com.tw/files/GT-511C­3_datasheet_V1%201_20131127.pdf
http://www.adh-tech.com.tw/files/GT-511C­1R_datasheet_V2-2016-10-25.pdf

--- Edit ---
About the profile size.. its 506 or 498 bytes depending on the sensor model.
As far as i can see i already can handle the profiles.. but the fingerprint images the sensor
can capture are in the order of 50kb.. and with that i had no luck. But before i could really dig in to it i destroyed my GT-511C1R.. but i was lucky.. my espruino wifi survived.