How to store value to object effectively

Question

I'm tackling the problem for a week. However, I couldn't find a solution. I feel I'm in a maze now.

The problem is that how to pen's coordinates in a vector-based drawing system by decoding hex input.

Thank you so much in advance.

Problem

Input Data: F0A040004000417F417FC04000400090400047684F5057384000804001C0 5F204000400001400140400040007E405B2C4000804000

Pen move condinates

This is my code

//Decode Value
penDecode = (hex) => {
    let decodeResult
    let hR = hex.slice(0, 2)
    let lR = hex.slice(2)

    let hByte = parseInt(hR, 16).toString(2).padStart(7, 0)
    let lByte = parseInt(lR, 16).toString(2).padStart(7, 0)
    let binary = hByte + lByte;
    decodeResult = (parseInt(hByte + lByte, 2)) - 8192

    return decodeResult
}



//Slice input
for (let i = 0, len; i < hex.length; i += len) {

    len = hex[i] >= '8' ? 2 : 4;
    let num = hex.slice(i, i + len)
    command.push(num)

    if (num.length === 2) {
        switch (num) {
            case 'C0':
                opcode = num;
                break;

            default:
                opcode = ''
        };
        else if (num.length === 4) {
            //decode HEX to the value 
            num = penDecode(num)
            switch (opcode) {
                case 'C0':
                    if (mvCurrentArr.length <= 1) {
                        mvCurrentArr.push(num)
                    } else {
                        mvArray.push(mvCurrentArr)
                        mv += `(${mvCurrentArr[1]},${mvCurrentArr[0]})`
                        mvCurrentArr = []
                        mvCurrentArr.push(num)
                        output += mv
                    }

            }

Expected output Output become same as the picture above MV (4000, 0) (4000, -8000) (-4000, -8000) (-4000, 0) (-500, 0);