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[Crispin]

Peeps,

Finally had a [broken] chance to play with my Netduino. Here's a quick class I wrote for measuring distances.

It's very simple, needs some polishing and commenting. I'll get to it

I've used it, along with someone else's serial class (apologies, I cannot remember who wrote it! ) to show distances on my Cat's Whisker LCD (What a nice piece of kit!)

Anyway....

    class Distance
    {
        public enum SensorType //mV/Inch
        {
            Maxbotix_LV_EZ = 10
        }

        private Cpu.Pin inputPin { get; set; }
        private AnalogInput analogInput { get; set; }
        public SensorType sensorType { get; set; }
        public double vRef { get; set; }

        private const double _mmPerInch = 25.4;
        private const double _inchPerFoot = 12.00;
        
        public Distance(Cpu.Pin analogInputPin, SensorType sensorType)
        {
            this.inputPin = analogInputPin;
            this.analogInput = new AnalogInput(inputPin);
            this.sensorType = sensorType;
            this.vRef = 3.3;
        }

        public double getDistanceIn_CM()
        {
            return getDistanceIn_mm() / 10.00;
        }

        public double getDistanceIn_Inch()
        {
            return _baseDistance();
        }

        public double getDistanceIn_Feet()
        {
            return _baseDistance() / _inchPerFoot;
        }

        public double getDistanceIn_mm()
        {
            //double _base = _baseDistance();
            //return  _base * (double)25.4;
            return _baseDistance()  * _mmPerInch;
        }


        private double _baseDistance()
        {
            //double ar = Convert.ToDouble(analogInput.Read().ToString());
            //double v = (vRef / 1023.00) * ar;
            //double dis = v / ((double)sensorType / 1000.00);
            //return dis;
            return ((vRef / 1023.00) * (Convert.ToDouble(analogInput.Read().ToString()))) / ((double)sensorType / 1000.00);
        }

    }

I need to double check the results and add some bits but for now, it's shows I can do it

Usage:

   public static void Main()
        {
            SerialPort UART = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
            OutputPort led = new OutputPort(Pins.ONBOARD_LED, false);
            Distance dis = new Distance(Pins.GPIO_PIN_A0, Distance.SensorType.Maxbotix_LV_EZ);
            SerialCom serial = new SerialCom(UART);
            string sDis = "";
            while (true)
            {
                sDis = dis.getDistanceIn_CM().ToString();
                Thread.Sleep(250);
                led.Write(!led.Read());
                serial.print("Distance: " + sDis + "\n");

                Debug.Print(sDis);
                Thread.Sleep(250);
            }
        }

It was a bummer I could not use the pw output. I cannot see a way to measure uSec in .net so resorted to analogIn. The sensors do have serial com on them but I see that as a waste of my precious UARTss.



I'm a database mechanic by trade, write c# (normal and compact) as a hobby / other bits and pieces. Always appreciate comments on how to improve stuff (I'm an efficiency freak and want it as slim as possible!)

Cheers,
Crispin

edit: can't upload the solution for this Will work it out in the morning...