node-red-contrib-minelert-universal-io/utils/smartlink-utils.js

Node-RED nodes for Universal IO Gateway and I/O Modules

function toMeters(value, unit) {
    switch (unit) {
      case 'cm': return value / 100;
      case 'mm': return value / 1000;
      default: return value; // 'm'
    }
  }

function convertLevelToMilliAmps(value, unit, mode,  min, max, height) {
    let input = parseFloat(value);
    
    if (isNaN(input)) {
        return {error: 'Payload must be a number'};
    }

    let valueForMapping;
    let mA;
    let percent;

    const result = {};

    input = toMeters(input, unit);

    result.readingToMeter = input

    if (mode === 'distance') {
        valueForMapping = input;
          
        if (valueForMapping < min) valueForMapping = min;
        if (valueForMapping > max) valueForMapping = max;

        result.value = valueForMapping;
        mA = 4 + ((valueForMapping - min) / (max - min)) * 16;

        percent = (valueForMapping / max) * 100;

    } else if (mode === 'level') {
        let level = Math.round((height - input) * 1000) / 1000;

        if (level < 0) level = 0;
        if (level > height) level = height;

        result.value = level;
        mA = 4 + (level / height) * 16;
        percent = (level / height) * 100;

    } else {
        return {error: 'Invalid mode'};;
    }
    
    result.percent = Math.round(percent * 100) / 100;
    result.mA = Math.round(mA * 100) / 100;

    return result;
}

module.exports = {
    toMeters,
    convertLevelToMilliAmps
};