Hi! Found a few things to be a little odd, I'm not sure they'll solve your problem though. You are creating the trigger port each time GetDist() is called. If you wish to share the same trigger pin among multiple class instances, declare the trigger port member as static instead and make sure it only gets created once. Create both the trigger and echo ports in your constructor and store them in private members. Remove the pin members since there's no point in remembering those any more. About interrupts, when adding an event handler, you are only registering a method to be called if and when an interrupt occurs. You are not, as your comment implies, waiting for it to happen at that point. This also means you should move event handler registration to the constructor as well. How are the the instances ultraSonic1 and ultraSonic2 created, what parameters are passed to the constructor?

Hi and welcome to the forum! It sounds as if you got it wired correctly but beware the Netduiono analague ports are not 5V tolerant. You could try feeding the module 3V3 instead of 5V and see what happens. I'm not saying you have but there's a possibility you might have damaged the ADC of your Netduino. According to the discription, you should get a transition (in either direction doesn't clearly state which) on the digital pin when the sound pressure exceeds a certain threshold depending on the potentiometer position. Could be transition is made from high to low so try wiring to an interrupt port and have it trigger on both edges. Then put a Debug.Print in the event handler and see if you get anything as you clap and dial the pot slowly from one extreme to the other. I assume that if you had a scope, you would have already used it so I guess you either don't have a one or didn't see a signal According to the review, you need to make a pretty loud noise for it to react, like clapping your hands very close to it. Since you probably already tried this, it would seem to me you got a rotten egg :-(

Pleae note that the free version "Visual Studio Express" will work just fine for working with the Netduino. I recommend getting a Netduino Plus 2 as it is the most versatile with built-in networking and on-board SD card slot. Netduino mini is very small but not as powerful. Good luck!

Hi! Start by removing the do...loop in Sub Main, instead use Thread.Sleep(Timeout.Infinite). Next, both your threads will exit as soon as sensor and button reads true respectively. Once a thread exits its method, it stops running and won't get called again per se. Therefore, replace the "loop untill..." with just "loop" in each of the corresponding methods and it should work better. Better still would be for you to declare both sensor and button as Interrupt ports and then use the interrupt to turn motor rotation on and off depending the edge being high or low.

The Netduino would have to implement a CDC class USB device. I'm pretty sure that would have to be done in native code for performance reasons. I beleive the likeliness for that being included in a coming firmware release is pretty slim so you'd have to do it yourself. This has been discussed before:

 

http://forums.netdui...oard#entry50164

 

Another option could be to implement a USB HID device class and use that for communication. This has been done in managed code, try this Google query and you will find some threads about HID:

 

http://www.google.se...etduino.com HID

 

While using HID from PC application is rather easy (there are libraries), it's not generic like serial communication so you would have to write a dedicated PC application.

If the meter unidirectional and "read only": UART signals are quite simple active low pulses, look it up on wikipedia and you'll see how to interpret the signal. At 300 baud, it should possible to read using an interrupt enabled GPIO. You would then analyze the time difference in between the slopes. Also, It just might be possible to read it at 1200 and then convert the data afterwards (you would typically receive each bit four times). Start och stop bits might present problems though. If the meter is bidirectional, I think you could use one of these: https://www.sparkfun.com/products/9981

I forgot to say earlier; move the if block to inside the do...loop for both threads.

It so happens that the pin you are claiming is electrically connected to an on-board LED. When disposing the pin, it reverts to its default config and usage. I'm not sure but, could it be the pin (and thus the LED) is used as a power indicator on your board?

I used an MCP41100 digital pot for drawing the signal and here's the code for it:

http://forums.netdui...-potentiometer/

Can you see what the oscilloscope says? 

 

 

I'll be uploading some code later so we can compete in drawing the best oscilloscope art 

 

You might want to look at this old post:
http://www.avsforum....for-itach-irule

And perhaps also this one:
http://itachtoolkit.codeplex.com/

And maybe this too:
http://forums.netdui...ased-ir-remote/

All in all you can build your own iTach emulator or HTTP listener on an NP or NP2 to carry out the commands against whatever h/w you want to control.

The thing is that the iRuleAtHome remote control and builder is just awesome, I use it for all kinds of stuff in my house. I even use it to turn the christmas tree on and off during that time of year. In this post there's a video on controlling a Netduino mini over ethernet:
http://forums.netdui...m-a-smartphone/

You can of course also do it with a PC, Raspberry PI or what have you.

This is not directly related but looks an interesting way to build smartphone apps for interfacing with your Netduino, for example via sockets over a network.

 

As I understand, XMarine would enable you to use Visual Studio for writing apps for both Android and iOS devices.

 

http://xamarin.com/

 

To me it sounds very cool. Has anyone of you guys tried it?

Faith, what controller is it, got a datasheet you can point to?

That makes it compile but it's not quite the same thing, I'd say it translates into this:

if ((this_led_color & mask) != 0)       SDI.Write(true);else       SDI.Write(false);

Checking for equality to mask is no longer the same when mask has other than a single bit set.

I agree, a Netduino is not a good choise for those things and I don't even think the PI could cope. Any of those would probably be a really big detour from achieving what you want. As all of the bullets are pretty high level stuff, I'd recommend using a PC. Later, you could move to a micro or nano ATX if size is important. Of course, a Netduino could perhaps handle some of it but what's the point if you got s PC on the side. To be quite honest, I think the stuff you've mentioned taken together could take years to develop no matter what hardware you got.

You should use an interlocked exchange to change the value of the _serverReady varible. The Interlocked.Exchange method will replace the value and return the previous value in a single atomic (unbreakable) operation.

int _serverReady = 1;if(Interlocked.Exchange(ref _serverReady, 0) == 1){            // process request       .      .      .      // done, open unlock the door      _serverReady = 1;}else{      // server busy}

As indicated above, I think you have to declare _serverReady as an integer for this work. You might want to use the volatile modifier on your variable declaration but I don't know if that feally matters in .NETMF. There might also be a way to configure the listener as synchronous so that the server will never attempt to process requests in parallel. Could be this feature is not available in .NETMF, I'm not sure.

The shield is probably based around the Maxim MAX7456 chip. Sparkfun has a similar board based on the MAX7456: https://www.sparkfun.com/products/9168 That one has been discussed in these threads: http://forums.netdui...58-netduino-tv/ http://forums.netdui...-video-overlay/ I'm pretty sure I've seen it in other posts as well but I can't find that info right now. Hope that helps a little anyway.

Hi all!

 

The MCP41100 is a programmable digital potentiometer with SPI interface and comes in a breadboard friendly DIP-8 package. You can set it to any value between 0 (zero) and 100 kOhm in 256 steps. You can of course tweak it into doing other ranges by wiring in series or in parallel with other (fixed) resistors.

 

For another project, I needed to produce a variable voltage between 0 (zero) and 5V so I made a simple driver class for it and thought I'll share it with you. Attached you'll find the driver and demo app. It is written for my beloved mini but works with others too requiring only small modifications.

 miniMCP41100.zip   4.51KB   7 downloads

 

You simply use it like this:

var r = new MCP41100(new SPI.Configuration(Pins.GPIO_PIN_17, false, 0, 0, false, true, 10000, SPI.SPI_module.SPI1));// set half resistance (i.e. ~50k)r.Level = 128;// set zero resistancer.Level = 0;// ...or you can use the Resistance property to set ~50k like sor.Resistance = 50000;// set ~100kr.Resistance = 100000;

The demo app assumes the IC has been wired as a voltage divider like in this schematic (Pw = output):

When connected that way, you can use it as an a very slow "arbitrary signal generator" meaning you can pretty much draw any signal over time like I did in this post or a nice sine wave if you prefer that:

 

I guess you could think of the MCP41100 like a "poor man's DAC"  but since the mini does not have a DAC, it can actually very useful at times as it's also much simpler than to use PWM.

 

Enjoy!

 

EDIT: Note that the MCP41100 is not suited for signal generation in general.

Hi, That "first chance" is from an exception being caught in a try...catch and the second is an exception (the same?) not being caught. I suppose the error is what it is said to be, e.g. an object that unexpectedly has a value of null. Since the code has run for quite a while and the exception looks not to originate from your own code, my guess would be that it is due to unsufficient memory available or something else that builds up over time. I would think its hard for anyone to say much more about it having not seen your code.

Very nice, at first I didn't see the Lumia but only an old 5110 but then I noticed the animated "fly by" arrows and reallzed the 5110 was never capable of that. Thanks for sharing! Edit: also, congrats on becoming a Nokia Developer Champion!

Yes, I even mentioned PWM in the end of my post. Naturally, the MCP41100 is not at all intended for signal generation (for many reasons), it just seemed like a "fun thing" as opposed to being something of practical value. 

Speaking of PWM, below is a sine(-ish) wave form that I generated using a UART and an LP-filter. It was done using a regular USB to TTL UART converter cable with code running on the PC in an attempt to produce audio - see how beautifully smooth it is?   

 

Also, I was actually thinking of doing PWM audio on an MSP430 but someone beat me to it:

 

I would have thought it be unusual for an SPI slave device to ignore chip select but could be it only looks at the raising edge of the clock as long as !cs is asserted, i.e. performing and AND operation on the two. Maybe that is defacto standard procedure. The parameters you set do matter and controls how the Netduino SPI module manages the cs and clock pins respectively but I guess you knew that already.

Instead of Unit-testing, you might consider "black boxing" by writing a corresponding set of interfaces through which data Is introduced. You would then make your fake implementations always returning fixed or random dummy data as needed. Later of course, you would make real (non-fake) implementations.

If you mean what the pin is used for, I believe it is for supply voltage 7.5 - 9V.

Hi! While looking for adjacent info, forum member emg mentioned this module: http://www.ebay.co.u...e-/270762577188 That and other alternatives was discussed in this thread: http://forums.netdui...for-rtc-backup/