edbot/util.js

Edbot Node.js API module

//
// Edbot Software API Node.js module utility functions.
//

// We need to return a sensible number if the distance is out of range.
var OUT_OF_RANGE = 100.0

//
// IR sensor IRSS-10. Convert raw value to cm.
//
// Calibration: A white A4 card was held a known distance from the sensor and
// the raw sensor value was noted. This was repeated for different distances.
// The following function was derived by fitting a curve to the set of data
// points.
//
// The measuring range is approx 3cm to 30cm.
//
// Return the distance in cm rounded to 1 decimal place or OUT_OF_RANGE.
//
module.exports.rawToIRSS10Dist = function(raw) {
	if(raw < 26) {
		return OUT_OF_RANGE;
	} else if(raw > 713) {
		return 3.0;
	} else {
		return round(214.32803656545 * Math.pow(raw, -0.60223538294025299184), 1);
	}
}

//
// IR sensor DMS-80. Convert raw value to cm.
//
// Calibration: A white A4 card was held a known distance from the sensor and
// the raw sensor value was noted. This was repeated for different distances.
// The following function was derived by fitting a curve to the set of data
// points.
//
// The measuring range is 8cm to 80cm.
//
// Return the distance in cm rounded to 1 decimal place or OUT_OF_RANGE.
//
module.exports.rawToDMS80Dist = function(raw) {
	if(raw < 111) {
		return OUT_OF_RANGE;
	} else if(raw > 740) {
		return 8.0;
	} else {
		return round(19490.373230416 * Math.pow(raw, -1.16498805911575493846), 1);
	}
}

//
// Temperature sensor TPS-10. Convert raw value to degrees Celsius rounded to 1
// decimal place.
//
module.exports.rawToTPS10Temp = function(raw) {
	return round(0.1179268 * raw - 34.86361, 1);
}

//
// Touch sensor TS-10.
//
// The touch sensor is a micro-switch. Return 1 if the switch is depressed,
// otherwise 0.
//
module.exports.rawToTS10Touch = function(raw) {
	if(raw > 0) {
		return 1;
	} else {
		return 0;
	}
}

//
// Magnetic sensor MGSS-10.
//
// The magnetic sensor is a reed switch which detects the presence of a magnet.
// This function returns 1 when a magnet is present, otherwise 0.
//
module.exports.rawToMGSS10Mag = function(raw) {
	if(raw > 0) {
		return 1;
	} else {
		return 0;
	}
}

//
// Servo motor SM-10.
//
// Return the angle of the servo from 0 to 300 degrees rounded to 1 decimal
// place.
//
// Note the raw range of the SM-10 is 64 -> 959 and not 0 -> 1023.
//
module.exports.rawToSM10Angle = function(raw) {
	if(raw < 64) {
		return 0.0;
	} else if(raw > 959) {
		return 300.0;
	} else {
		return round(300.0 * (raw - 64) / 895.0, 1);
	}
}

//
// Internal IR sensor in the CM-150 Dream micro-controller. Convert raw value
// to cm.
//
// Calibration: A white A4 card was held a known distance from the sensor and
// the raw sensor value was noted. This was repeated for different distances.
// The following function was derived by fitting a curve to the set of data
// points.
//
// The measuring range is 3cm to 20cm.
//
// Return the distance in cm rounded to 1 decimal place or OUT_OF_RANGE.
//
module.exports.rawToCM150Dist = function(raw) {
	if(raw < 26) {
		return OUT_OF_RANGE;
	} else if(raw > 681) {
		return 3.0;
	} else {
		return round(108.47751089561 * Math.pow(raw, -0.51378200718609424542), 1);
	}
}

//
// Internal IR sensor in the CM-50 Play micro-controller. Convert raw value
// to cm.
//
// Calibration: A white A4 card was held a known distance from the sensor and
// the raw sensor value was noted. This was repeated for different distances.
// The following function was derived by fitting a curve to the set of data
// points.
//
// The measuring range is 3cm to 20cm.
//
// Return the distance in cm rounded to 1 decimal place or OUT_OF_RANGE.
//
module.exports.rawToCM50Dist = function(raw) {
	if(raw < 26) {
		return OUT_OF_RANGE;
	} else if(raw > 681) {
		return 3.0;
	} else {
		return round(108.47751089561 * Math.pow(raw, -0.51378200718609424542), 1);
	}
}

///////////////////////////////////////////////////////////////////////////
//
// Private.
//
///////////////////////////////////////////////////////////////////////////

function round(number, prec) {
    var factor = Math.pow(10, prec);
    var temp = Math.round(number * factor);
    return temp / factor;
}