shiv.kumar

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?

@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?