Rod Lopez

Hi guys,

A few months ago I was finishing a robotics project and ended up hitting pretty hard limitations on the Arduino platform, I switched to a Netduino, and life was good... other than minor issues I came across at the time.
I have a similar situation now with a different project, it started with Arduino and I am thinking about moving over once again. I just wanted to get a heads-up on what the current state of the platform is.

So, if anybody could help with a couple of questions, here they go!

-Can I communicate though USB? I am storing information in an SD card that I would need to read, it used to be that the USB(digital 0-1) were only for debugging, is that still so? I am using all pins on the Arduino, I won't be able to use the second UART for sending data over.

-I remember some conversation on low-power modes, but it all seemed on the air (waiting for 4.2 and so). Is there anything working today? My application is fairly power-critical (big batteries but must last for months), I could trigger a hardware interrupt if that's needed

-I might be producing a few tens of devices in the next six months or so, how well does the Netduino/MCU scale in terms of production? (I am thinking chip availability, bootloading, etc) In the Arduino you can buy a blank chip, program it and have it running on a custom PCB in no time

-I have found some cases for the Arduino (I particularly like the one Adafruit has), is there any that's Netduino-friendly? Netduino having the usb plug in a different location and so...

thanks a ton!

Can I power the Netduino using unregulated 7.5-12 volts though the vIn pin in the board? as in... instead of using the power connector If so.. what's the maximum power I can drain? (I have a few 3.3 and 5v devices connected to the Netduino)

Hi all, I am trying to debug a simple yet specially tricky situation, I am trying to measure both voltage and current going through a certain circuit. The voltage is no big deal, resistor divider: Vcc----1M---+A0---470k---GND ..and I measure across A0 and GND, all good. The problem is the current, I add an extra resistance, so things look a bit like Vcc----1M----+A0---470k--10---+A1----GND At that point, though I get a decent reading for current, my reading for voltage goes to hell... My guess is that the internal resistance between A0 and A1 is lower than I expected (acording to the change in result it should be around 500k), so that one would appear in parallel with the 470k resistance and kill my reading. I can throw an opAmp (or lower the divider's resistors)and be over with it fairly quickly, but I would like to make sure I understand what's going on. Does anybody know what the internal inter-pin resistance should be? thanks!

Hi there,
I am having a very simple issue, I am trying to write a few values to a 16x2 LCD, the values are, originally floats. I need to be able to see the whole set of info in a single glance.

The issue is that, by default, I end up printing too much (the number plus eight digits of precision), so my result doesn't fit on the screen at all.

My code looks like this:

	float A = 0, V = 0;
	PowerSampling.GetPower(ref V, ref A);
	Write("V " +  V + " A:" + A + " W:" + A * V);

...and the code I am trying to replicate (I am porting this from an Arduino) looks like this:

	float A, V;
	PowerSampling.GetPower(V, A);
	lcd << "V" << _FLOAT(V, 1) << " A" << _FLOAT(A,2) << " W" << _FLOAT(V * A,1);

I was intending to use String.Format but that doesn't seem to be supported... how can it be done?

Hi there,
This is my first post here, so please let me know if I am posting in the wrong place

So, as to the issue...
I have a setup where I am using one of the Netduino COMs as serial interface to an external chip (an IMU), communication works, and everything is fine and dandy (a.k.a I get my data through the serial), but I eventually (pretty much at predictable intervals) get an 'Out of Memory' error.
I honestly thought that moving to a managed framework meant that you didn't have to care about your memory anymore, is that true? do I need to release / dispatch memory blocks somehow? Do I need to manually invoke the garbage collector?
Could you give a look to the code and tell me if I am doing something terribly wrong?

thanks!!
-rod

IMUSerial = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
IMUSerial.DataReceived += new SerialDataReceivedEventHandler(IMUSerial_DataReceived);
IMUSerial.Open();

//write IMU code
Debug.Print("Serial is " + (IMUSerial.IsOpen? "open" : "not opened"));
byte[] pip = System.Text.Encoding.UTF8.GetBytes("r");

Debug.GC(true);
while (true)
{
	IMUSerial.Write(pip, 0, 1);
	Thread.Sleep(100);
	
}

static void IMUSerial_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
	byte[] buffer = new byte[10];
	IMUSerial.Read(buffer, 0, 10);
	String message = new String(System.Text.Encoding.UTF8.GetChars(buffer));
	Debug.Print(message);
}