Alright, I took out some time to continue to play using an RC network to smooth out the PWM signal to simulate a "steady" DC voltage.

For my application of the Bar graph display I'm really only interested in being able to control the exact number of LEDs I want turned on or off. That is, I'm not so concerned about being able to read the actual analog voltage. Of course the LM 3914 is actually reading the analog voltage and turns on/off LEDs accordingly. But I'm only concerned with being able to send a PWM signal from the Netduino such that I can deterministically control the actual number of LEDs that need to be turned on. I say this because the RC network introduces lag and so the choice of the RC components could be different for your purposes. Further, I also need to be able to turn on all 10 LEDs at 3.3v.

I found that a 2.2K resistor connected to the PWM output pin on the Netduino and a 10uF capacitor connected between the other end of the resistor and ground works best. Of course the junction of the two is fed to the LM 3914 ICs pin 5. The LM 3914 and the LEDs are running off of 5v.

EddieGarmon,

Thank you for the reply and suggestion.

I thought about doing that but didn't, thinking that would introduce delays in the response. However, I'll certainly try it as my needs for response times are not so drastic, however, accuracy is important. I'll get back to the forum once I've had an opportunity to try it.

I'm trying to drive an LED bar graph (using the LM 3914 chip as the driver). So what I need is to provide it with voltages from 0v-3.3v (for my needs.).

I tried PWM, but it doesn't work as expected (not accurate). If anyone has done this using PWM I'd be interested is learning how.

Hi Nevyn, thanks for your reply.

Hmm, so we don't have analog output ports. I guess the other option is to use an external DAC? Has anyone tried a specific board?

Does anyone know how to use the AnalogOutput ports? I'd like to be able to output voltages between 0v-3.3v using these ports.

I'm stuck at trying to initialize the ports. That is:

private AnalogOutput analogOutput = new AnalogOutput(Cpu.AnalogOutputChannel.ANALOG_OUTPUT_0);

Compiles ok, but I get an Exception at runtime. Exception message has no useful information. I've tried the other constructor overloads as well (with various values), but no luck.

I'm guessing the analog outputs have 8bit resolution? Also, if anyone knows, I'm guessing I could simply write values from 0-255 to get output voltages from 0-3.3v. Is this correct?

@Daniel

This is what I use for all of my "Networked" application including those for the Netduino Wi-Fi 3

        /// <summary>
        /// This method works for Ethernet connected devices (such as NetDuino Plus 2) as well
        /// as Wi-Fi connected Devices (such as Netduino 3 Wi-Fi)
        /// </summary>
        private static void WaitForNetworkConnectivity()
        {
            Debug.Print("Waiting for IP Address...");
            while (Microsoft.SPOT.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces()[0].IPAddress == "0.0.0.0") ;

            Microsoft.SPOT.Net.NetworkInformation.NetworkInterface networkInterface = Microsoft.SPOT.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces()[0];

            Debug.Print("IP Address: " + networkInterface.IPAddress);
        }

There are no assemblies you need to reference other than those included in a blank (ND Wi-Fi 3) project. The ND Wi-Fi projects have a reference to:

Microsoft.SPOT.Wireless.IEEE_802_15_4

In addition to the default. Hope this helps.

By the way, would you mind sharing the code/library required for your LCD display? And the make/model of your display as well please?

@Nevyn, did you read the part about TLS and SSL support? Also in the US a shield would cost $25-$30 and the advantage is that it is conveniently mounted along with the ND making the "gadget":

1. More self sufficient.

2. Easily deployable in the field and/or transportable

3. Driven by a battery pack (or less power nonetheless)

4. No Ethernet cable required

5. The router or network cable is not always conveniently located or accessible to the ND on the home or office

if TLS/SSL were not a requirement maybe we could have a solution that uses one of the $5 USB dongles 

I think it would be beneficial for those of us who have the Netduino Plus 2 to be able to have a tried and tested Wi-Fi shield that plugs into the Ethernet socket on the board (if that's even possible). Nonetheless, a tried and tested Wi-Fi shield would be a great product.

I'm not sure if there is a tried and tested Wi-Fi solution but I do like the TLS and SSL support built into the CC3100. Has anyone tried using the CC3100 with the Netduino Plus 2?

In order to configure the Wi-Fi (as HSven1611 mentioned), one has to use th eMFDeploy tool. One can find this tool in the .NET Micro framework SDK (something I didn't know about - that is where to find it). for the SDK version 4.3 it can be found here

C?:\Program Files (x86)\Microsoft .NET Micro Framework\Tools\

Once I found it, I was able to configure the Wi-Fi with the DNS server's IP address as well as the WPA  from the Target | Configuration | Network menu option. The dialog presented has the fields you'll need to fill in. Make sure your device is connected to your PC.

Just is case others may see my earlier post in this thread and assume there is an issue with using the Netduino 3 Wi-Fi and PWM.....There is not problem and things do work s expected. My apologies for any confusion I may have caused.

Sorry guys, false alarm.

I have a static class with a static PWM member in my project. It is not used (referenced) anywhere in the project. However one of the PWM pins was conflicting with another class that was in use). It seems that in NETMF, static members are initialized even though the type itself is never referenced.

It took me a while to nail it down but eventually, I commented the class out and that cured the problem and so that's how it figured this issue out.

Anyway, I do have my Netduino 3 Wi-Fi working with PWM working as well. Whew!

Hi Paolo,

Thanks for the great library! It works like a charm too. I have it working on the Raspberry PI 2 and the Netduino 3 Wi-Fi. I'm using Topics in my application where both the devices subscribe to a topic. I haven't yet gotten around to these devices publishing messages to their own topics. But do plan to. So it's one-way at the moment.

Any way to get this working on Netduino Plus 2?

I have some issues with using PWM in Netduino Wi-Fi 3 and as a result of which I can't use ND WiFi- 3 and would like to use ND+2.

Shiv.

I have a simple project that uses PWM to dim and brighten the on-board LED.

 public class Program
    {
        public static void Main()
        {
            PWM led1 = new PWM(PWMChannels.PWM_ONBOARD_LED, 100d, 0.001d, false);
            led1.Start();
            while (true)
            {
                for (var startValue = 4.712d; startValue < 10.995; startValue = startValue + 0.005)
                {
                    double endValue = System.Math.Sin(startValue) * .5 + .5;                    
                    led1.DutyCycle = endValue;
                    Thread.Sleep(10);
                }
            }
        }
    }

This works as expected only if I don't reference the Microsoft.SPOT.Wireless.IEEE_802_15_4 assembly.

If I do reference this assembly then the PWM doesn't work. Just to be clear, I don't make any code changes. I simply add the assembly reference.

Has anyone else experienced this? Or could someone try this on their end to see if they get the same behavior ?

Years later....

I should have got back here to let folks know that I got this to work (soon after my last post in this thread).

Basically, the issue was related to levels. The RX/TX pins need to be level shifted to work with the Netduino. In my case since I'm using the Bluetooth module as a receiver, I've pulled up the TX pin of the Bluetooth module (not the Netduino) with a 10k resistor.

That is, the TX pin of the Bluetooth module (in addition to being connected to pin 0 of the Netduino is also connected to 3.3v via a 10k resistor. After doing this, the above test (the very first post in this thread) works as expected. That is, I don't get gibberish and in fact get exactly the data I send via the terminal.

I hope this helps.

@TechnoGuy, thank you so much for the detailed explanation of where to find MSDeploy. I think this should be part of the instructions, honestly. This version of MFDeploy, has the screen for setting up the Wi-Fi which also sorts out the other issue I had.

Again, really appreciate the detailed reply. Can we put your reply in a document that can be linked to from the downloads page?

I have an empty (no code) NetDuinoApplication project (VS 2015).

Running it, I get this exception

an unhandled exception of type 'System.NullReferenceException' occurred in Netduino.IP.Linklayers.CC3100

I don't have the Wi-Fi configured (Not able to figure out how to get that to work). The Wi-Fi light it yellow/orange).

What could be wrong? Also, how can I configure the Wi-Fi on the board?

Ok, so I uninstalled and reinstalled the Netduino SDK. I now see the device in MFDeploy as "Netduino3_Netduino". When I ping the devce I see "Pinging...TinyCLR". Is this correct?

Questions:

1. If the Netduino 4.3.2 the latest version?

2. Where can I get MFDeploy? (I think I have an older version that I downloaded from the internet)

In MFDeploy, I see IP setting, but no place to provide credentials for my Wifi. Where am I supposed to be able t see and set these settings?

Just got my Netduino 3 Wifi and attempted to apply the 4.3.2.2 update. The first time I updated I could see my Netduino in the MFdeploy tool but I couldn't see anywhere to provide my wireless network credentials.

Anyway, I tried all sorts of things and eventually MFDeploy wasn't seeing my Netduino. So I decided to Erase the flash. I the saw my device (in Device Manager as "STM Device in DFU Mode" when powered on with the button pressed).

However, I did see my Netduino in the Netduino Update tool as Netduino 3 Wi-Fi. so I selected it and updated. I then saw the device in Device manager under "Other Devices" as Netduino 3 W-Fi but with an exclamation icon. I now don't see the device in MFDeploy (selecting USB or any of the others).

What can/should I do next?