No scope (it got stolen years ago... very sad day for me) but certainly a multimeter. The measurements I remember for 3.3V were 3.29V and when using the lipo battery, 11.9V on Vin. My multimeter is pretty cheap, but the readings were always steady. I might be able to borrow a scope tonight to take a deeper look. edited to add: using a usb power brick is another great idea!

Man were you wrong! I'm not in Colorado, near a ski slope, OR skilled! Can't even get a thermistor circuit to work.

Ok I took some measurements and notes:

#.5V...3.3V.VIN.....Powersource
1 4.73 3.29 1.26....PC USB - short cable
2 4.22 3.26 1.08....PC USB via long cables and usb hub
3 4.99 3.30 11.79...Lipo Battery
4 5.05 3.29 1.56....Motorola Droid USB Charger

The only scenario where the analog input has been stable (+/- 1 step) is #2... oddly enough.

I still don't have a scope, so this is the best I can do at the moment.

As a recap, I have a wire going from 3.3V to Vref, and a voltage divider using a 47K resistor and a thermistor. I also have three LEDs for indicators. Attached is a badly drawn schematic.

Any more suggestions? Thanks!! --Bill

Yeah, that was a smart idea. If you have a ND+ and never need to leave your local subnet, you could store 4 bytes in your default gateway, maybe?

I would have expected these basic functions to be supported on the netduino.

Am I naive for thinking these functions are almost the polar opposite of basic?

wiki on IMUs: http://en.wikipedia....easurement_unit

Also: I think your diagram needs a ground connection on pin 8.

Thanks, Omar, I was just getting ready to try out my shift registers.

Ballpark, how much $$ are we talking about?

If you don't mind me asking, what kind of project are you working on?

Thanks for this, I have been playing with an MCP3204 -- i was wondering the "proper" way to combine the two bytes into the reading.. bitwise operators have always been mysterious to me. I got it working but my solution does not look nearly as smart as yours...

I have been having a ton of problems getting decent, stable readings, though. Do you have any sample circuits and pictures you could post?

Here are some premade boards i've been thinking about:
http://www.mikroe.co.../easyadc-board/
http://www.mikroe.co...dc-proto-board/

That looks cool! But how did you get the netduino icon to appear on the display?

I was going to post it, but it's huge. I wrote this method (see above):

public void drawbitmap(byte[] bmp)

... and passed it in a static readonly byte array, a trick I learned from your fluent interopt stuff. I modified my c# code generator to do (byte) instead of (short), and had it read from a 8 bit bitmap file i generated from one of the 4D tools. I'll post more of a snippet tonight. I also have text working, but there's lots more work to do -- for instance, feeding it a file off the netduino SD card, or interfacing with the screen's SD card.

I was introduced to this lcd in this thread: http://forums.netdui...ch__1#entry7229 -- and I got it working:



It's a 128x128 1.44" color LCD, with a serial interface and a "graphics processor" attached. Sparkfun has them for about $32. One of the comments from the Sparkfun page:

So let me get this straight. This thing is a color LCD with built in controller, backlight circuitry, microSD socket which is compatible with both low capacity and high capacity cards, AND! it basically has a user programmable microcontroller with 10k of program space and 2 GPIO lines in addition to all the on-board control lines for interfacing with the LCD?

The product pages are here: uLCD-144(GFX)

4D has two versions: GFX and SGC. GFX is basically a "standalone" version, meaning you program the built in controller directly, and can built an interface to whatever you want (netduino, pic, etc -- but you have to write the interface)

SGC is more like a "traditional" serial display, where you send it command like "draw a circle here", "display this text", etc.

At first I thought the difference was actually in the hardware, but it's not: it's just firmware. You can reflash the GFX to the SGC and back without any trouble. You can get the SGC firmware here.

I was able to power, test, flash, and program it using the 3.3v Sparkfun FTDI breakout via a breadboard, in spite of the board requiring 5v. I did have to manually toggle the reset line, but it was flawless, otherwise.

Here is the start of the class I'm building to interface with it:

using System;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
using System.IO.Ports;

namespace uLCD_144_Test1
{
    class uLCD_144
    {
        public SerialPort _COM2;
        public void init()
        {
            using (OutputPort d4 = new OutputPort(Pins.GPIO_PIN_D4, true))
            {
                d4.Write(false);
                d4.Write(true);
            }
            Thread.Sleep(2000);
            this.write(new byte[] { (byte)0x55 });
        }
        public void drawbitmap(byte[] bmp)
        {
            //2.2.5 Draw Image-Icon - 49hex
            //Command cmd, x, y, width, height, colourMode, pixel1, .. pixelN
            byte[] cmd = new byte[] { (byte)0x49, (byte)0x00, (byte)0x2A, (byte)0x80, (byte)0x28, (byte)0x08 };
            this.write(cmd, false);
            this.write(bmp);
        }

        public void write(byte[] ba, bool pause = true)
        {
            if (this._COM2.IsOpen)
            {
                this._COM2.Write(ba, 0, ba.Length);
                int sleeptime = (ba.Length / 14) + 1;  //(calculate transmission time, at 115200, it can send 14 bytes / ms
                Debug.Print(sleeptime.ToString());
                if (pause)
                {
                    Thread.Sleep(sleeptime);
                }
            }
            else
            {

            }
        }
        public uLCD_144()
        {
            this._COM2 = new SerialPort(SerialPorts.COM2, 115200);
            this._COM2.Open();
            this.init();
        }
    }
}

Hi there. It just needs 5v to the vin, ground, then you hook the tx/rx to the rx/tx on either uart (i used com2 above but have switched to com1 now) and then any io to the reset to be able to reset the device. In the above code I used D4, but have since switched to A5. Edit: and "yes" to the SGC question.

Yes, it is awesome, but comes with a price -- it's a little pricey, and it is small. It also can generate sound on the other pin. It's crazy. I am building a library to mirror the all the SGC commands, then I'll go from there. Part of me would like to get it to dial out via a modem and connect to a bbs or something. Use lynx to surf the web? LOL

www.hobbycity.com has lots and lots of servos at very low prices.

I am not sure how much is left after the Netduino have taken it´s share from the regulator.

/Jan Olof

Should be plenty! And yes, debug.print should put stuff in the "output" window -- it should be in the lower left, although you might have to select the "output" tab. I can't remember, I set it up my visual studio layout some time ago, and the settings stick.

the line with the a5.read, I convert to a string, I believe it normally returns a number, so if you did something like:

int i = a5.read();
if (i > 20)
{
// do whatever
}

If you want to get the analog readings in mV, search the forums for "setrange".

That's a cool little car. Is this all you're looking for, to test? Hook up 3.3v to aref, and the analog output from the sensor to A5 (plus whatever else the sensor needs, like power and ground), and i think you'll be all set to test.

using System.Text;
using Microsoft.SPOT;
using System.Threading;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;


namespace NDP_SocketSender1
{
    public class Program
    {
        public static void Main()
        {
       
            AnalogInput a5 = new AnalogInput(Pins.GPIO_PIN_A5);

            while (true)
            {
                string s = a5.Read().ToString();
                Debug.Print(s);
                Thread.Sleep(100);
            }
        }
    }
}

The above code is from here.

linksys 5v poe

This injector puts in 48v but spits out 5v.

Can you elaborate on the keypad/analog input issue?

Really? Why?

I imagine in real life you have a very strong personality. It comes across in your posts. Instead of hopes and wishes, you have expectations and demands. This has served you very well in life! I'd like to know and understand where in your life this comes from, as I try and find my own path in the world, as I'm sure besides helping you advance through life, it's even helped others around you achieve, if not in admiration of you, than out of fear of disappointing you. I bet you are a good leader. Some people might "get" you, and others might think you come across as a bit of a jerk sometimes, but both will work hard for you.

So, I get ruffled when I think you might be acting like a jerk to Chris and the state of the union here. But this is just me being oversensitive and trying to learn about life and technology. And Chris is his own successful person, with an awesome product, quoted in magazines, etc. and can fend for himself!



I'd like to check out this: http://www.sump.org/...nalyzer/client/
or this: http://www.lxtreme.nl/ols/
using this: http://dangerousprot...-logic-sniffer/ -- which i just noticed is doing exactly what I was doing with decoding IR in this pic:

Don't get me wrong, I love the .Net Micro Framework

...but not the Netduino, Secret Labs, or Chris Walker???
Your posts ruffle my feathers! I'm still reeling from the basic comment on loading assemblies.
But, you're obviously brilliant and successful, so, I am still a Fabien Fan. I wish I was at least better looking, but we kind of look like we could be brothers.

PS: Bill, how do you like your Saleae analyzer so far?

I like it, it's very "sexy" in a mac sort of way, and works in 7 and OSX.
..but, if feels very basic, feature wise. I've never used a logic analyzer before, so I'm not sure what I'm expecting. I was trying to "reverse engineer" an IR signal with it, and while it was useful, there was no way to compare two "bit trains" side-by-side from different samples, so I was cutting and pasting screen shots into paint.net. I have no idea if any logic analyzer has that sort of functionality. The software essentially has no menus, so I found myself hungry to do simple things like split the screen in two vertically.

Let me start off by saying that I think the netduino and the netmf is wonderful. *BUT* this is something you need to know coming into this, if you've ever done anything with lower level micro controllers. Folks "new to the sport" probably won't run up against this for a while.

There was a bit of discussion on this in an earlier thread:
http://forums.netdui...ch__1#entry6380

... also interesting, in the quadrocopter discussion, I had checked out the timings using my saleae logic and you can see what is apparently the scheduler getting involved:
http://forums.netdui...ndpost__p__7645

I did some new measurements with my saleae so i could zoom in and provide a different perspective of what you're talking about:
using this code: (this was so I could get the timings of the on/offs as equal as possible)

while(true)
{
b = !b;
d0.write(B);
}

I got this:

and using this code: (which is faster)

while(true)
{
d0.write(true);
d0.write(false);
}

I got this:


There is lots of interesting things to think about, I think.
1. It's interesting to me how much slower the first example is
2. We might want to keep track of these types of timings to have a handle on if firmware changes impact the timings at all
3. I wish I could mail Corey my saleae to get the timings under his fluet interopt... which is awesome. (Or, alternatively, I with I was brave enough to try it myself!)
http://www.youtube.com/watch?v=9EcEUbtgO2I
4. I wonder what the impact of things like GC and the scheduler are

#2 sounds like the start of development of a test suite for the netduino, where we can independently test the netduino during firmware upgrades. I might consider taking on this project myself. (Once I learn what a test suite is)

time zones too...

I'm more concerned about firewalls.