FEZ DOMINO analog out

NETMF & Gadgeteer
1

hi guys, I have not been able to get a signal out of the analog out port (An3 port). I’m using an oscilloscope to measure from An3 to GND and i still have no results. please help.

code:


        public static void Main()
        {
            // Blink board LED

            bool ledState = false;

            ///////////////////////////////////////////////////////////////////////////////
            //Setup buffer for DSP calculations

            int[] Reg_Buffer;
            Reg_Buffer = new int[2500];

            AnalogIn BatteryVoltage = new AnalogIn((AnalogIn.Pin)FEZ_Pin.AnalogIn.An0);
            BatteryVoltage.SetLinearScale(0, 3300);

            //for (int i=0; i<2499; i++)
            //{
            //    int voltage =BatteryVoltage.Read();
            //    //sleep for 3 ms
            //    Thread.Sleep(3);
            //    Reg_Buffer[i] = (voltage/1000);
            //}

          
            ////////////////////////////////////////////////////////////////////

            ///////////////////////////////////////////////////////////////////////
            //Setting up analog out

            AnalogOut VoltLevel =
            new AnalogOut((AnalogOut.Pin)FEZ_Pin.AnalogOut.An3);
            VoltLevel.SetLinearScale(0, 3300);
          ////////////////////////////////////////////////////////////////////////

            //////////////////////////////////////////////////////////////////////
            //difference(ref Reg_Buffer);
            //square(ref Reg_Buffer);
            //integral(ref Reg_Buffer);
            //display(ref Reg_Buffer, ref VoltLevel);

                ////////////////////////////////////////////////////////////////////////

                ///////////////////////////////////////////////////////////////////////
                OutputPort led = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.LED, ledState);

                // create serial port for bluetooth . Connect BLUETOOTH_RX to Di8 and BLUETOOTH_TX to Di7.
                SerialPort bluetooth = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
                bluetooth.Open();

                while (true)
                {
                    // create heart rate information bytes
                    byte[] helloBytes = Encoding.UTF8.GetBytes("1");

                    bluetooth.Write(helloBytes, 0, helloBytes.Length);
                    //////////////////////////////////////////////////////////////////////////////////////////////////

                    VoltLevel.Set(1000);


                    //// toggle LED state
                    ledState = !ledState;
                    led.Write(ledState);
                    //sleep for 3 ms
                    Thread.Sleep(2000);
                    VoltLevel.Set(0);
                }

           

            
        }
        
    }
2

Keep it simple, remove all unrelated code and only set the analog output then measure it with a volt meter.

3

The voltmeter reads -4.67 volts (strange).

code:


public static void Main()
        {
            // Blink board LED

            bool ledState = false;

           

            AnalogIn BatteryVoltage = new AnalogIn((AnalogIn.Pin)FEZ_Pin.AnalogIn.An0);
            BatteryVoltage.SetLinearScale(0, 3300);

         

            ///////////////////////////////////////////////////////////////////////
            //Setting up analog out

            AnalogOut VoltLevel =
            new AnalogOut((AnalogOut.Pin)FEZ_Pin.AnalogOut.An3);
            VoltLevel.SetLinearScale(0, 3300);
          ////////////////////////////////////////////////////////////////////////

          
           ///////////////////////////////////////////////////////////////////////
            OutputPort led = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.LED, ledState);

              
                while (true)
                {
                    

                    VoltLevel.Set(1000);


                    //// toggle LED state
                    ledState = !ledState;
                    led.Write(ledState);
                    //sleep for 2s
                    Thread.Sleep(2000);
                    VoltLevel.Set(2000);
                }

           

            
        }
4

Okay i got it working. how do i see what the code below is outputing? the fez domino has no screen (confused).

code:

Debug.Print("Voltage = " + (voltage / 1000).ToString() + "." + (voltage % 1000).ToString());
5

These messages are displayed in the output window of visual studio during debugging.

6

im sorry i know this might sound foolish but how do i get the output window to show?

7

Ctrl+w, o

8

You can also view the Debug.Print statements in MFDeploy, if you are not running the app under debugger in Visual Studio.

9

Watch out with analog input if it comes to voltage!!! Never exceed 3.3v on analog in.
(I can’t say it often enough)

If you need help, here is how I did it:

http://robertjacobs.eu/2011/02/03/voltage-dividing-reading-battery-voltage/

A lot of people reading battery voltages lately :o

10

im trying to sample a signal and output it through An3 in real time. im getting a quantized signal.

code:

public static void Main()
        {
            // Blink board LED

            bool ledState = false;

            ///////////////////////////////////////////////////////////////////////////////
            //Setup buffer for DSP calculations

            AnalogIn BatteryVoltage = new AnalogIn((AnalogIn.Pin)FEZ_Pin.AnalogIn.An0);
            BatteryVoltage.SetLinearScale(0, 3300);

            ////////////////////////////////////////////////////////////////////

            ///////////////////////////////////////////////////////////////////////
            //Setting up analog out

            AnalogOut VoltLevel =
            new AnalogOut((AnalogOut.Pin)FEZ_Pin.AnalogOut.An3);
            VoltLevel.SetLinearScale(0, 3300);
            ////////////////////////////////////////////////////////////////////////



            ///////////////////////////////////////////////////////////////////////
            OutputPort led = new OutputPort((Cpu.Pin)FEZ_Pin.Digital.LED, ledState);

          
            int voltage = 0;
            while (true)
            {
               
            /////////////////////////////////////////////////////////////////////////////////////////////////////


                voltage = BatteryVoltage.Read();
                //// toggle LED state
                //ledState = !ledState;
                //led.Write(ledState);
                //sleep for 3 ms
                Thread.Sleep(2);
                VoltLevel.Set(voltage);
                Thread.Sleep(1);
            }




        }
11

NETMF is not real time but you can use the tasking we offer in RLP. That is real time