Should be just fine. The digital io pins on the N+2 are 3.3v.

Totally agree, being able to simply plug in a battery and get an RTC would be fantastic.

Ahh Steve thanks..  I haven't done much server or PWM work before so it was pretty easy to doubt my understanding.  I ran through several tests and verified that changing the period does not have any effect on the position with a given duration, so I feel better that it's not related to some magic number ratio.

 

 

Thomas

Admittedly I'm still wrapping my head around what the hardware does with a period of 20000 and a duration of 2500.  My tests show that I needed to double my durations when my period is set @ 20000.  The documentation that you read indicating position should not be nebulous, with your statement of 1ms or 2ms.  Typically there is a very specific pulse for a very specific position.  

 

I've yet to figure out why I have to double my pulses to get the levels that I expect.

 

My understanding is that a period of 20000 means 20ms from pulse to pulse... and 1.5 ms duration means how long.  The question really for me is whether it is supposed to be a ratio of the period, or an amount of time.  

 

I pulled NETMF 4.2 driver code from the forum, but I pulled my hair a bit until I realized that I got exactly the results that I expected when I doubled my durations from the tech spec, but the example code all showed similar boundaries to what I was expecting.  

 

So.. either my servo  (HS-322HD Deluxe) is very different from others in the example or the example code has never been tested on the N+2.

 

Tech spec shows pulse widths of 600 to 2400 for 180 degree motion with a 20ms pulse cycle.

 

No answers really just more questions.

Hi Thomas - Thanks for posting this. I have the DS18B20 One Wire temperature Sensor (https://www.sparkfun.../products/11050) and was wondering if this would work the same for what I have? I am a .NET Developer who is a complete newbie to electornics. Is there a chance you could post how you wired up your temperature sensor to the Netduino Plus if it is not too much trouble. I have the NP 1 but would assume there is not much of a difference?

Thanks!

Don

 

Don, I just realized that you indicated that you've got an NP1, and while that would not effect wiring much if at all, the NP1 does not have built in OneWire support.  You have a couple of options as I can see.

 

1: Build a custom firmware with OneWire support (there are posts on the forum about it)

2: Use a hardware OneWire translater or build one yourself with an attiny or pic

3: Upgrade to the NP2

 

Thomas

I've got one, but haven't played with it much.  Having too much fun with my Netduino right now to figure out their IDE and programming.  I like the fact that it's inherently got wireless communication out of the box...

Hi Thomas - Thanks for posting this. I have the DS18B20 One Wire temperature Sensor (https://www.sparkfun.../products/11050) and was wondering if this would work the same for what I have? I am a .NET Developer who is a complete newbie to electornics. Is there a chance you could post how you wired up your temperature sensor to the Netduino Plus if it is not too much trouble. I have the NP 1 but would assume there is not much of a difference?

Thanks!

Don

I'm not sure if the protocol is the same for the DS18B20, but I know that I had trouble finding DS1821 solutions because it is non-addressable.  I think there are many example solutions for the DS18B20.    http://www.tinyclr.c...earch?q=DS18B20  http://forums.netdui...-using-onewire/ also has some descriptions for wiring.

 

Best of luck.

Hi,

How can i have OneWire function in Firmware 4.2.0 ? I guess it is successor of Firmware 4.1.0 so it must have this in it,doesn't it?

ThankYou

I have successfully used OneWire in Firmware 4.2.1.2. So I can confirm that it is in that firmware.

There are a few examples on the forum for onewire executions.. like http://forums.netdui...re-temp-sensor/

http://forums.netdui...etduino-plus-2/

Have you looked at the advanced tutorials example on
http://www.netduino.com/projects/

I think it is a working example of your objective. I apologize for not answering why your code doesn't work.

I'm having a problem with ending a NativeEventHandler(button). The problem is main thread stuck at the join() function. I dont understand why the childthread is not released after it is run.

public class Program
    {
        private static Thread mainThread;
        private static Thread childThread;     

        private static InterruptPort button = new InterruptPort(Pins.GPIO_PIN_D1, true, Port.ResistorMode.PullUp, Port.InterruptMode.InterruptEdgeLevelHigh);
      
        private static OutputPort led = new OutputPort(Pins.ONBOARD_LED, false);
        
        public static void Main()
        {            
            mainThread = Thread.CurrentThread;
            Thread.Sleep(1000);
            while (true)
            {
                Thread.Sleep(100);
                button.OnInterrupt += new NativeEventHandler(ButtonEvent);
                mainThread.Suspend();
                childThread.Join();//It stuck here.
                Thread.Sleep(100);
                button.EnableInterrupt();
                button.ClearInterrupt();  
            }
        }

        private static void ButtonEvent(uint port, uint state, DateTime time)
        {
            childThread = Thread.CurrentThread;
            button.DisableInterrupt();          
            mainThread.Resume();
           // Thread.CurrentThread.Abort(); this .Abort() seems doesn't terminate the thread either.
        }
    }

I've ported my DS1821 code over to use Microsoft.SPOT.Hardware.OneWire. Thought I would share it out in case anyone else had these devices.

public class Program
    {
        static OutputPort owPort = new OutputPort(Pins.GPIO_PIN_D0, false);
        static OneWire DS1821 = new OneWire(owPort);

        public static void Main()
        {

            lcdDisplay.Clear();
         
            while (true)
            {
                string tmp = GetTemperature().ToString("F2");
                lcdDisplay.SetCursorPosition(0, 0);
                lcdDisplay.Write(tmp);
                Thread.Sleep(100);
            }

        }

        public static float GetTemperature()
        {
            ushort temp_read = 0;
            ushort count_remain = 0;
            ushort count_per_c = 0;
            ushort configuration_register = 0;
            ushort whileCount = 0;

            // One -Shot Convert Temp
            DS1821.TouchReset();
            DS1821.WriteByte(0xEE);

            // Loop and sleep a bit until it is done converting the Temperature data.
            do
            {
                Thread.Sleep(10);

                configuration_register = 0;
                DS1821.TouchReset();
                DS1821.WriteByte(0xAC);

                // Read the configuration Register from the DS1821
                configuration_register = ReadBytes(1);
                whileCount++;

            } while (((configuration_register & (1 << 7)) == 0) && whileCount < 100); // If Bit #8 is 1 then we are finished converting the temp

            if (whileCount >= 100) return -1;
            // Get Temp
            DS1821.TouchReset();
            DS1821.WriteByte(0xAA);
            temp_read = ReadBytes(1); ;

            // Get Count Remaining
            DS1821.TouchReset();
            DS1821.WriteByte(0xA0);
            count_remain = ReadBytes(2);

            // Load The Counter to populate the slope accumulator
            DS1821.TouchReset();
            DS1821.WriteByte(0x41);

            // Read Count Per Deg
            DS1821.TouchReset();
            DS1821.WriteByte(0xA0);
            count_per_c = ReadBytes(2);

            // If we are reading above the 200 mark then we are below 0 and need to compensate the calculation
            if (temp_read >= 200) temp_read -= 256;

            var highResTemp = (float)temp_read - .5 + (((float)count_per_c - (float)count_remain) / (float)count_per_c);

            return (float)((1.80 * highResTemp) + 32.00);

        }

        static ushort ReadBytes(ushort count)
        {
            ushort val = 0;
            for (ushort i = 0; i < count; i++)
            {
                val |= (ushort)(DS1821.ReadByte() << i * 8);
            }
            return val;
        }


    }

Boom just ordered mine.. Super stoked.

Roy, have you considered using an optoisolator / optocoupler to physically separate the electrical circuits? Not sure if you want to read the analog, but for basic switching it should make you feel safe that you aren't going to fry your netduino.