Espruino test code for Velostat + copper based mat (i-Mattress-Sens-U-Pedic 2000)

pressure_mat_1.js

var ipins = [A3, A4, A5];
var opins = [B2, B3, B4];

var xs = opins.length;
var ys = ipins.length;

function readCol(x) {
    var j, k, res=[];

    // First, set the column lines to either +3.3V or "pin open circuit"
    for (j=0; j<xs; j++) {
        if (j == x) {
            // Set selected column as +3.3V
            pinMode(opins[j], 'output');
            digitalWrite(opins[j], 1);
        }
        else {
            // Set unselected columns as floating ("Digital output that
            // only ever pulls down to 0v. Sending a logical 1 leaves the
            // pin open circuit")
            pinMode(opins[j], 'opendrain');
            digitalWrite(opins[j], 1);
        }
    }

    // For each row in the selected column...
    for (j=0; j<ys; j++) {

        // Condition all other rows to 0V
        for (k=0; k<ys; k++) {
            if (k==j) continue; // Skip selected row

            // Set unselected rows as output 0V
            pinMode(ipins[k], 'opendrain');
        }

        // Read value (0.0 - 1.0) from selected row
        res[j] = analogRead(ipins[j]);
    }

    // Return an array of all row values (0.0 - 1.0) in the column
    return res;
}



var max = 0;
function upd_max (v) {
    if (v > max) max = v;
    return true;
}

function idx_val (v) {
    return ("   "+Math.round(100*v/max)).substr(-3);
}

function exec() {
    var x, y, arr, res=[];

    for (x=0; x<xs; x++) {
        res[x] = arr = readCol(x);

       // arr.every(upd_max);
    }

    max = 1;

    res.every(function (c) {
        console.log(c.map(idx_val).join("\t"));
    });
    console.log(' ');
}

function init() {
    while(true) exec();
    //(exec, 100);
}

init();