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#60330 SD Card Write issue

Posted by sfx on 03 October 2014 - 12:08 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi Dizel,

 

The full .NET Framework will ensure that a FileStream object is disposed of by any wrapper objects that get created (e.g. StreamWriter etc). Because of this, it isn't necessary to call dispose (via a using statement) on a wrapped FileStream since the wrapper will do it for you. Of course, in the interests of readability and consistency it is good practice to always explicitly declare your intentions on a FileStream with either a using statement or a try/finally block. However, I'm not sure if NETMF behaves the same way as its big brother on this.

 

At any rate, it appears that instead of your StreamWriter instance wrapping your FileStream object both are wrapping the shared file path. This indicates to me you have two Stream derived objects competing for the same resource at the same time.

 

Try this:

using (FileStream file = new FileStream(fileWrite, FileMode.OpenOrCreate, FileAccess.ReadWrite))
using (StreamWriter wr = new StreamWriter(file))
{
    wr.WriteLine("Hello");
    wr.WriteLine("StreamWriter");
}

Take care,

 

Nathan




#60232 .NET Micro Framework V4.3 SDK-R2-Beta

Posted by sfx on 26 September 2014 - 01:02 AM in General Discussion

Hi Chris,

 

I've done as you said and everything seems to be working well now. Thanks for your help!

 

Nathan




#60231 enc28j60_lwip_recv: input alloc packet failed

Posted by sfx on 25 September 2014 - 09:31 PM in Netduino 2 (and Netduino 1)

Hi Wendo,

 

Can you show us how your code is being called from a timer? The more context we have the better we will be able to troubleshoot the problem. For instance, in the past, I have had problems with application "halts" when using timers in the conventional way.

 

Nathan




#60215 .NET Micro Framework V4.3 SDK-R2-Beta

Posted by sfx on 25 September 2014 - 01:17 AM in General Discussion

Hi Chris,

 

Thanks for the quick reply.

 

The SDK that I uninstalled was "netduinosdk_vs2013_experimental.exe". The SDK that I installed (following the new NETMF SDK) was "netduinosdk_NETMF43.exe".

 

Should I now uninstall the latter and reinstall the former?

 

Take care,

 

Nathan




#60213 .NET Micro Framework V4.3 SDK-R2-Beta

Posted by sfx on 24 September 2014 - 11:30 PM in General Discussion

Hi Chris,

 

Thanks for the instructions.

 

I've followed your points -> Uninstall NETMF SDK -> Uninstall Netduino SDK -> Install NETMF SDK -> Install Netduino SDK.

 

Unfortunately, however, I can no longer see any Netduino project templates when creating a new project. I've tried rebooting a couple of times, but to no avail. Do you know what tooling I might be missing from SecretLabs?

 

Take care,

 

Nathan




#60202 .NET Micro Framework V4.3 SDK-R2-Beta

Posted by sfx on 24 September 2014 - 07:43 AM in General Discussion

Thanks for the heads-up CW2!

 

For those of us who have already installed the experimental VS2013 tooling from SecretLabs, do we now need to uninstall it or can these distributions exist side by side?

 

Take care,

 

Nathan




#60126 Mayhew Labs Mux Shield II

Posted by sfx on 16 September 2014 - 12:12 PM in Beta Firmware and Drivers

Hi All,

 

I’ve been wanting to expand the number of analog inputs in my N2+ so I purchased a Mux Shield II (Mayhew Labs), but have been unable to get the thing working. All I’ve had to go on is the Arduino user guide and code samples which I’ve attempted to port to NETMF, unsuccessfully it seems. Has anyone else had any experience using this multiplexing shield? I noticed that a forum member, Eric Falsken, created a code sample for the previous Mux Shield but I’m unable to get that working with the new board. His post can be found here:

http://forums.netduino.com/index.php?/topic/2975-mayhew-labs-muxshield-and-ti-74hc4067/?hl=74hc4067

 

I would definitely appreciate some help on this since accessing more analog inputs without having to design my own circuit was something I was really hoping for with this shield.

 

The user guide for the shield can be found here:

http://mayhewlabs.com/media/Mux_Shield_II_User_Guide.pdf

 

Along with Arduino code samples:

http://mayhewlabs.com/code/MuxShield.zip

 

Take care,

 

Nathan




#59958 Netduino Analog Ports

Posted by sfx on 31 August 2014 - 12:28 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi All,

 

The Netduino has 6 analog ports (A0-A5). Can anyone tell me an easy way to extend the number of analog ports so that more can be addressed?

 

Take care,

 

Nathan




#59327 New Robot Meetup Group, Seattle

Posted by sfx on 21 July 2014 - 09:52 AM in General Discussion

Hi Spiked,

 

So I guess that means I won't be getting any video recordings of your affronts (ahem... efforts)?

 

Sorry to hear that it did not go down so well. It sounded like many weren't there to grow, but to agro instead. I guess it doesn't come as a huge surprise, really, since I've seen my fair share of egoism and self-aggrandisement within the software community as well. Sadly, many of this type adroitly tout their cross-discipline expertise while at the same time being blissfully unaware that their behaviour satisfies the Dunning-Kruger effect.

 

Please don’t give up, though. Many here can still learn from your expertise and there are undoubtedly a plethora of matters where your contribution will be both substantive and welcome.

 

Nathan




#59322 NETMF SerialPort and "BreakState"

Posted by sfx on 20 July 2014 - 11:52 PM in Netduino Plus 2 (and Netduino Plus 1)

Hi jrlyman3,

 

This is fantastic! Thanks for posting this for me. My HC-SR04 has not arrived yet, but your code will give me something to work with out of the gate. Much appreciated!

 

Nathan




#59281 Windows on Devices? When?

Posted by sfx on 17 July 2014 - 01:09 PM in General Discussion

 

Does anyone understand why a device would boot windows then provide an exact emulation of an arduino (using wiring as the language and NO ui?).

 

Provide an emulation for a heretofore foreign experience on Windows? Yes. Microsoft has done this before (much to the chagrin of some of its developer community). Recall that Microsoft unleashed JavaScript - a foreign language - into WinRT development with the sole ambition of luring a broader cross-section of developers into their fold. Microsoft must think there is enormous money in the IoT, and it appears they want to cast their net as wide as possible.

 

Shake an apple tree and you better have a bucket ready. Shake an orchard, and...

 

Nathan




#59274 New Robot Meetup Group, Seattle

Posted by sfx on 17 July 2014 - 04:29 AM in General Discussion

Hi Spiked,

 

Good to hear! Keep us all posted on any further developments regarding meeting access. I, for one, would really appreciate the benefit that this type of experience would bring.

 

Nathan




#59269 New Robot Meetup Group, Seattle

Posted by sfx on 16 July 2014 - 11:31 PM in General Discussion

Spiked,

 

What a fantastic idea! I would love to be able to attend this kind of setup, but unfortunately I live far, far away (and there aren't any facilities like this around where I live).

 

Would it be possible to video record the meetings and then make them available offline? Obviously there would be costs involved in this, but I'd be happy to pay for any expenses. If downloadable material is too cumbersome to setup, how about a no-frills mail order DVD?

 

Nathan




#59244 NETMF SerialPort and "BreakState"

Posted by sfx on 16 July 2014 - 04:57 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi jrlyman3,

 

Am I interested? Of course!

 

When you get a moment, I'd welcome any samples that you think might be of some help.

 

Nathan




#59227 Windows on Devices? When?

Posted by sfx on 15 July 2014 - 05:30 AM in General Discussion

Hi Dr Who,

 

Yes, that's true. Unfortunately, I also noticed (or at least couldn't find) references to either the Netduino or NETMF on the IoT Developer portal...

 

Nathan




#59211 Windows on Devices? When?

Posted by sfx on 14 July 2014 - 05:38 AM in General Discussion

Hi All,

 

Looks like there has been an update:

 

http://blogs.windows...am-for-iot.aspx

 

Nathan




#59210 NETMF SerialPort and "BreakState"

Posted by sfx on 14 July 2014 - 05:34 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi jrlyman3,

 

Thanks for the feedback. I'm definitely going to test out a HC-SR04 now.

 

Nathan




#59189 NETMF SerialPort and "BreakState"

Posted by sfx on 13 July 2014 - 10:11 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi Baxter,

 

Sweet indeed.

 

As usual, thanks for the great references. Thanks also for your code samples. I’ve put them in a folder called “Baxter Serial”. Now there’s a name for a new design!

 

I’m going to purchase the HR-SR04, but I’m ideally on the lookout for a single transducer range finder so I’ll probably purchase something from MaxBotix as well (though I’m not sure about the connections on these since I’ll probably have to solder [something new again] wires to them).

 

Of course, I’m open to any further suggestions you have. Hopefully I’ll be able to build something out with these that doesn’t cost me my sanity.

 

Nathan




#59176 NETMF SerialPort and "BreakState"

Posted by sfx on 12 July 2014 - 02:06 PM in Netduino Plus 2 (and Netduino Plus 1)

Hi Baxter,

 

Sorry for the delay in getting back to you, I’ve been at this thing hammer and tong since we last spoke and wanted to be sure of my findings before I replied to your last post.

 

Thanks for the excellent references too. I’ve had the electronics book you mentioned for a little while now but haven’t acquired the starter kit yet in order to really get the most out of it. I’ve also read the books by Cuno and Chris and have been watching the videos on allaboutcircuits for a couple of weeks now. It’s quite a crash course!

 

Now for finally some good news… Since the last time I discussed this issue with you I went back to my setup (using your diagram) and realised that I had a 1N4001 diode in the place of where the BAT 48 Schottky diode that I had purchased should be. Well, guess what happened when I replaced the diode? It worked! I finally started to receive data back across the wire!! I therefore want to offer you my sincerest thanks as well as hearty congratulations. If it wasn’t for your help, I would never have got this far with my limited hardware experience...

 

Now for some not so good news… The code samples that I’ve worked on that were taken from the vendor’s website, as well as others that I’ve attempted to port from different platforms, don’t seem to work on the Netduino. The problem appears to be in how data is waited upon as well as how echo transmissions get discarded before any relevant bytes can be parsed – I just couldn’t get the Netduino to read anything but junk using the code samples I found online... And so...

 

Now for some interesting news... I did finally manage to get the range bytes by using the DataReceived event of the serial port, but only after what I consider to be a bit of a hack; or more specifically, by collaborating with the number of times the received event gets raised and then parsing the relevant bytes accordingly. It seems to work, but it’s definitely a code smell.

 

Due to all of these issues, I’m not certain I will settle on the SRF01 as the range finder I want to use on the Netduino. Nevertheless, it’s only because of your assistance that I’m even able to consider this option.  More importantly, your solution has not only helped me, but it will aid anyone who is searching online for how they can connect a SRF01 to the current release Netduino hardware.

 

Well done!

 

Nathan




#59156 NETMF SerialPort and "BreakState"

Posted by sfx on 11 July 2014 - 12:02 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi Baxter,

 

Wow! Thanks so much for taking the time to diagram that circuit out for me. I really appreciate it.

 

Thanks also for the reference to EasyEDA. I haven’t heard of it before (not surprisingly), but will start playing with it immediately.

 

I’ve created your diagram on my Netduino Plus 2 and attached a picture of the result. I think I have everything in essentially the same order as you.

 

Unfortunately, I’m still not reading anything on the SerialPort.BytesToRead property. It is always zero. This has got me thinking that surely it shouldn’t be as difficult as it has been to set this kind of configuration up on the Netduino. After all, the Arduino can read these sensors without even having to move a circuit out onto a breadboard! As such, I’m left wondering whether there is something wrong with my own hardware or if the NETMF doesn’t play nice with serial communication outside of its standard operational boundaries. I find both of these possibilities quite troubling, but also think that it’s most likely the former rather than the latter.

 

I guess I’m going to have to wait until the USB to TTL adapter arrives in order to see whether my Netduino can operate against the vendor’s PC code.

 

I’m reluctant to have to abandon my venture and admit defeat, but I’m also aware that I might well be out of my depth here. Still, I’m very thankful for all the guidance you have provided over these last few days – I have definitely learned a lot. Nevertheless, I realise that I’m likely stealing your time away from other important matters. Hence, in the event that I can’t get anything working I was wondering if you happen to know of any companies that could prototype the setup that I’m after on the Netduino board? If there are facilities that can offer this kind of service I’d be happy to pay to at least get me a working sample from which I can then build upon.

 

Thanks again.

 

Nathan

Attached Thumbnails

  • NP2_Half-Duplex.jpg



#59140 NETMF SerialPort and "BreakState"

Posted by sfx on 10 July 2014 - 09:55 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi Baxter,
 
While I'm waiting on the USB to TTL adapter to arrive, I thought I would try to implement the transistor based half-duplex UART configuration that you mentioned to me earlier:
 
 
I have attached a diagram for the circuit in the above web page, but my circuit reading ability is still in its infancy and so I have a strong hunch that I have got it wrong. When you get a moment, I was hoping you could point out the innacuracies that I have made.
 
As I have each of these parts I'm hoping to be able to test out this configuration using an SRF01 as well.
 
Nathan

Attached Thumbnails

  • Half-Duplex-Software-UART.jpg



#59118 NETMF SerialPort and "BreakState"

Posted by sfx on 09 July 2014 - 09:45 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi Baxter,

 

No worries. I've cancelled the order and made another one for item (3) on your list. Hopefully I'll take delivery of it within the next few days.

 

Thanks also for the heads up regarding RS232 and TTL. Your explanation makes a lot of sense.

 

Regarding my Fritzing diagram, I have removed the blue wire as per your instructions but can confirm that this setup does not work using the GPIO with logical AND "break" substitute. More specifically, various commands can be sent without throwing an exception but the SerialPort.BytesToRead property is always zero.

 

Concerning the next to last diagram that I posted, I'll endeavour to build that out once my USB to TTL adapter arrives.

 

In the meantime, however, if you have any further suggestions or recommendations please let me know.

 

Nathan




#59114 NETMF SerialPort and "BreakState"

Posted by sfx on 09 July 2014 - 02:22 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi Baxter,

 

Further to your last response (and in addition to mine), I'm still uncertain as to how to layout a breadboard diagram for the "half duplex" solution that you mentioned - I guess I'm not clear on how both the RX and TX pins from the Netduino will connect to the logical AND gate. I've attached an image as to what I think you mean, but was hoping that you could validate it against the intent of your previous suggestion.

 

I’m wanting to try this out even before your serial adapter advice as I already have the necessary items and will likely have to wait a few days before I can acquire an adapter.

 

Thanks again.

 

Nathan

Attached Thumbnails

  • Half-Duplex-v1.jpg



#59113 NETMF SerialPort and "BreakState"

Posted by sfx on 09 July 2014 - 01:18 AM in Netduino Plus 2 (and Netduino Plus 1)

Hi Baxter,

 

It goes without saying, but I really appreciate your patience with me on this.

 

As per your suggestion, I’ve ordered a USB adapter similar to the one here:

http://www.ftdichip....0_R-100-500.pdf

 

Just so you know, I have multiple SRF01’s available to use and have tested with more than just one. Unless I received a bad batch, then they all seem to be working the same way (power flash appropriate to the tech specifications). Additionally, the code that you referenced is the code that I have actually been working with since the beginning – I’ve only been consulting the Arduino code as a secondary verification.

 

I’ve attached another image showing what I think you were saying about connecting a serial port to a diode. Please let me know if I’ve misunderstood you. Once I have the serial adapter, I’ll test out this configuration along with any further suggestions you have.

 

Nathan

Attached Thumbnails

  • Serial-Diode_v1.jpg



#59102 InterruptPort/Events slow the first time

Posted by sfx on 08 July 2014 - 01:23 PM in General Discussion

Hi Frode,

 

Yes, that's right. I just tested it again and found that the initial press after deploy was trapped by the debugger almost immediately.

 

Nathan





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