Igor Kondrasovas

Hello,

 

I would like some tips about using a secondary power source (like a battery) to make sure that if my main power supply (on the power jack) goes down, my Netduino stills run.

 

I was thinking about using a secondary 5V battery attached to VIN pin. My questions are:

 

1 - Can I power Netduino using both the power jack and the VIN pin at the same time?

2 - If yes, will the battery power be used only when the main power is off? I am afraid that maybe the battery power will also be consumed....

 

Any other advice?

 

Thank you,

 

Igor.

 

Hello,

 

We are working in a project where we have to read data from electronic weight scales. The signals will come in 4-20mA signals that must be processed by Netduino Plus.

 

Suppose we solve the current to voltage conversion and deliver 0 to 3,3V to the Netduino analog input. We know there is some noise and some filtering may have to be applied. I believe this is common to most class of microcontrollers.

 

In order to minimize this noise, we were thinking about using some external ADC with SPI or I2C interface, like the Adafruit ADS1015 or MCP3008.

 

I would like to know if using these (or any other) chips or breakout boards will potentially provide lower noise levels? I mean, do they have a better noise immunity/treatment compared to the native Netduino ADC filter?

 

 

Thank you,

 

Igor.

Hello, Today one of my students experienced a problem while installing the free tools to work with Netduino. He is using a 64-bit Windows 8 RTM + Visual C# Express 2010 + .NET Micro Framework SDK 4.2 + Netduino SDK 4.2 64-bit. When he creates a new project, there is a very strange compiling error (shown in the attached image): Description: 0x80131700 File: MMP Has anyone experienced the same problem? How can I track down what is going on. I already removed/reinstalled everything with no effect. I appreciate any suggestions! Thank you, Igor.

Hi, It seems after VS2012 lauch, the 2010 Express versions do not have .ISO file download option anymore. It seems that only web installation is available. I need to have the .ISO for 2010 version to run my Netduino projects and the .ISO download is important to install in classes I teach. The Internet connections are not fast and reliable so we will loose too much time usint the download install. Do you know where I can download the ISOs ? Thank you, Igor.

Hello,

I am working in a very simple temperature reading project and I am experiencing some strange behavior during the first Analog input read.

To reproduce what I think it's strange, I created a simple code using Netduino Plus running firmware 4.2.0 (the code snippet on this forum editor does not work for me):

public static void Main()

{

AnalogInput adc = new AnalogInput(Cpu.AnalogChannel.ANALOG_0);

System.Threading.Thread.Sleep(5000);

double firstRead = adc.Read();

double secondRead = adc.Read();

while (true)

{

Debug.Print("First Read: " + firstRead.ToString());

Debug.Print("Second Read: " + secondRead.ToString());

System.Threading.Thread.Sleep(10000);

}

}

The while is only used to make sure I won't loose the messages when connecting to MFDeploy.


When I run this code using the Visual Studio debugger, first and second reads are very similar. No problem there. However, when I:

1 - Stop Debugging

2 - Unplug Netduino Plus

3 - Open MFDeploy

4 - Plug Netduino ON again (using the usb cable)

I have the following results:


First Read: 0.10166177908113393



Second Read: 0.078201368523949169


As you can see the first read always have a higher value than the second one. In my real project, this means the first temperature reading is always much higher then reality.

I included a 5 second delay before reading, since I was expecting there was some "port initialization" but this seems not to be the case, so you can get rid of it that the results are the same.

The most annoying thing is that when debugging in Visual Studio, I cannot see the behavior (It took me some time to figure out this).

Any thoughts about why am I seeing this? Any tests I could make?

Thank you,

Igor.