5 replies to this topic

[Lord Wheezy]

I get the following error when ever I try to execute the I2CDevice.Execute function.

#### Exception System.ArgumentException - 0xfd000000 (1) ####
#### Message:
#### Microsoft.SPOT.Hardware.I2CDevice::Execute [IP: 0000] ####
#### Phaser_6140.Program::Main [IP: 0106] ####
A first chance exception of type 'System.ArgumentException' occurred in Microsoft.SPOT.Hardware.dll
Exception was thrown: System.ArgumentException
Microsoft.SPOT.Hardware.I2CDevice::Execute


My code is as follows:

using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;

namespace Phaser_6140
{
    public class Program
    {
        public static void Main()
        {
            // write your code here
            OutputPort SDA = new OutputPort(Pins.GPIO_PIN_A4, false);
            OutputPort SCK = new OutputPort(Pins.GPIO_PIN_A5, false);
            SDA.Dispose();
            SCK.Dispose();

            InputPort button = new InputPort(Pins.ONBOARD_SW1, false, Port.ResistorMode.Disabled);
            OutputPort led = new OutputPort(Pins.ONBOARD_LED, false);
            bool pushState = false;
            bool pushStatePrev = false;
            bool ledState = false;
            bool ledBlinking = false;
            uint blinkCounter = 0;
            uint blinkcounterLimit = 1000;
            ushort writeAddress = 0xA0;
            ushort readAddress = 0xA1;
            int clockRateKhz = 100;
            I2CDevice.Configuration writeConfig = new I2CDevice.Configuration(writeAddress, clockRateKhz);
            I2CDevice.Configuration readConfig = new I2CDevice.Configuration(readAddress, clockRateKhz);
            I2CDevice eeprom = new I2CDevice(writeConfig);

            byte[] writeBuffer = new byte[1];
            writeBuffer[0] = 0;
            byte[] readBuffer = new byte[256];
            // create an i2c read transaction to be sent to the device.
            I2CDevice.I2CTransaction[] writeXAction = new I2CDevice.I2CTransaction[1];
            writeXAction[0] = I2CDevice.CreateWriteTransaction(writeBuffer);
            I2CDevice.I2CTransaction[] readXAction = new I2CDevice.I2CTransaction[1];
            readXAction[0] = I2CDevice.CreateReadTransaction(readBuffer);

            while (true)
            {
                try
                {
                    pushStatePrev = pushState;
                    pushState = button.Read();
                    led.Write(ledState);

                    if (ledBlinking)
                    {
                        if (blinkCounter > blinkcounterLimit)
                        {
                            blinkCounter = 0;
                            ledState = !ledState;
                        }
                        blinkCounter++;
                    }

                    if (!pushState && pushStatePrev)
                    {


                        Debug.Print("Change LED State");

                        //the i2c data is received here from the device.
                        int writeTransferred = eeprom.Execute(writeXAction, 1000);
                        eeprom.Config = readConfig;
                        //int readTransferred = eeprom.Execute(readXAction, 1000);

                        //make sure the data was received.
                        //if (transferred != readBuffer.Length)
                        //    throw new Exception("Could not read from device.");
                        //else

                        ledBlinking = true;

                        string buff = "";

                        for (int i = 0; i < 256; i++)
                        {
                            buff += readBuffer[i].ToString();
                        }

                        Debug.Print(buff);
                    }
                }
                catch (Exception e)
                {
                    Debug.Print(e.Message);
                    if (e.InnerException != null)
                    {
                        Debug.Print(e.InnerException.Message);
                    }
                    Debug.Print(e.StackTrace);
                }
            }


        }


    }
}

Any suggestions?

[CW2]

ushort writeAddress = 0xA0;
ushort readAddress = 0xA1;

The current I2C implementation supports only 7-bit slave address, so 0xA0 is out of range. You'd probably need to use 0x50 address and only one configuration - setting Read/Write bit is handled automatically depending on the type of transaction.

[Stefan W.]

Out of curiosity - what is the purpose of this?

            // write your code here
            OutputPort SDA = new OutputPort(Pins.GPIO_PIN_A4, false);
            OutputPort SCK = new OutputPort(Pins.GPIO_PIN_A5, false);
            SDA.Dispose();
            SCK.Dispose();

[Lord Wheezy]

The current I2C implementation supports only 7-bit slave address, so 0xA0 is out of range. You'd probably need to use 0x50 address and only one configuration - setting Read/Write bit is handled automatically depending on the type of transaction.

That did it thanks, CW2!

[Lord Wheezy]

Out of curiosity - what is the purpose of this?

            // write your code here
            OutputPort SDA = new OutputPort(Pins.GPIO_PIN_A4, false);
            OutputPort SCK = new OutputPort(Pins.GPIO_PIN_A5, false);
            SDA.Dispose();
            SCK.Dispose();

In one of the other I2C related posts It was suggested that setting and resetting the pins for SDK and SCL might help. I want to say it was one of the moderators, Chris Walker, made the suggestion. But I could be wrong and I lost track of the thread.

[Stefan]

In one of the other I2C related posts It was suggested that setting and resetting the pins for SDK and SCL might help. I want to say it was one of the moderators, Chris Walker, made the suggestion. But I could be wrong and I lost track of the thread.

It was suggested here:
http://forums.netdui...2299#entry12299

[Also, just for fun...try creating OutputPorts for pins A4/A5 and then disposing them right before you open up the I2C connection. If that fixes the issue, then there's a glitch in the firmware.]