CarTech

I'm using a netduino in a data logging application. I've integrated a GS1011 wifi board, GPS, accelerometer, Gyroscope, Compass, and OBDII/CAN to talk to my car. With all of these devices logging data to an SD buffer, memory is tight. If I try to post via the wifi connection, I run out of memory. I think I've optimized about as much as I can within reason. I understand that native code will run much faster and is useful for time-sensitive applications. This might be a dumb questions, but can I expect to see significantly less memory use if implement some drivers for the these devices in native and then call them from managed code?

I can't figure out which reference I need to use the System.Uri class. Opening a fresh project, I get this error message: type or namespace name "Uri" could not be found (are you missing an assembly reference?) error when I try something like the following.

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;

namespace TestingUri
{
    public class Program
    {
        public static void Main()
        {
            // write your code here
            Uri myUri = new Uri("http:\\www.google.com");
            
        }

    }
}

Please be kind as I'm a mechanical engineer during the day learning both C# and the netduino as a hobby.

I'm using an ADXL345 accelerometer connected to the netduino via I2C. I've attached the class for the accelerometer which I got almost directly from LoveElectronics ADXL345 Library & Tutorial. This code works very nicely.

Unfortunately the sensor stick from SparkFun, which I have, doesn't have the interrupts on the ADXL345 broken out. Thus, I've resorted to polling the ADXL345 with a timer.

The problem I'm having is that the timer only executes five times. If I change the time interval (tried 8ms and 800ms), it still only runs five times. Here's the problematic code:

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;

namespace Testing9DOF
{
    public class BufferFileManager
    {
        // Constructor
        public BufferFileManager()
        {
            Debug.Print("Created a new BufferFileMananger instance");
        }

        // Public methods
        public void StartDAQ()
        {
            // Start up sensor class
            ADXL345 myAccel = new ADXL345();
            myAccel.CheckConnection();
            myAccel.FullResolution = true;
            myAccel.EnableMeasurements();
            myAccel.SetDataRate(0x08);

            // Start collecting data to file
            Timer timer = new Timer(delegate(object o)
                {
                    myAccel.ReadAllAxes();
                    string data = myAccel.ScaledXAxisG + "\t" + myAccel.ScaledYAxisG + "\t" + myAccel.ScaledZAxisG;
                    Debug.Print(data);
                }, null, 0, 80);
        }
    }

    public class Program
    {         
        public static void Main()
        {
            BufferFileManager fm = new BufferFileManager();
            fm.StartDAQ();

            Thread.Sleep(Timeout.Infinite);
        }
    }
}

Now, if put everything in the Main class, it works fine:

using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;

namespace Testing9DOF
{
    public class Program
    {         
        public static void Main()
        {
            ADXL345 myAccel = new ADXL345();
            myAccel.CheckConnection();
            myAccel.FullResolution = true;
            myAccel.EnableMeasurements();
            myAccel.SetDataRate(0x08);

            // Start collecting data to file
            Timer timer = new Timer(delegate(object o)
            {
                myAccel.ReadAllAxes();
                string data = myAccel.ScaledXAxisG + "\t" + myAccel.ScaledYAxisG + "\t" + myAccel.ScaledZAxisG;
                Debug.Print(data);
            }, null, 0, 80);

            Thread.Sleep(Timeout.Infinite);
        }
    }
}

Not really sure what's going on. I'm guessing it's something to do with how I've attempted to put it in a second class? Any ideas?