I am working on the CAN on LPC1857 microcontroller. This is the first time I am working on the CAN driver.
I am right now testing the loopback mode in CAN. I have successfully transmitted the message. This I know because of the values in the status register. But now I need to verify whether I have received the same message at the receiver end. Since I do not have any oscilloscope with me, I wanted to know whether it is possible to check the output at the receiver end using software. I am using LPCxpresso IDE for the coding purpose. If yes, can you please give me a brief idea about how it is done?
Any help is appreciated.
Thanks,
Pavan.
Related
We are using an ICE video streaming solution using GStreamer. But for some reason I can't find out how to detect if the receiver has suddenly vanished. GStreamer just keeps happily sending data to no recipient.
I already had thoughts about using webrtcbin's "connection-state" property but not sure if this will actually work if the client just quietly drops. Seems like it will just stay in connected state. Plus very unsure about the implementation.
Any help would be greatly appreciated.
I have a LANBOX LCX device which is used for lighting up a few dimmable bulbs which are connected via DMX cables.
I have read the documentation and tried to find ways to send UDP, but as I am a newbie in lighting and DMX world, it is so hard to understand it.
Documentation: http://support.lanbox.com/Manuals/LanBox%20Reference%203.04.pdf
I have also tried some art-net programs to send data through that and also sending the mentioned bytes via UDP also. But none of them worked.
There are not much online resources also for this area.
If someone with knowledge about this particular area can help me, it would be really helpful.
If someone can help me with either sending art-net or UDP commands to the device to dim specific lights and light up specific lights, it will be really helpful.
Tried with the following documentations and GitHub repos:
https://www.artisticlicence.com/WebSiteMaster/User%20Guides/art-net.pdf
http://support.lanbox.com/Manuals/LanBox%20Reference%203.04.pdf
https://github.com/MikeCodesDotNet/ArtNet.Net
https://pypi.org/project/pyartnet/
I wanted to change the values in the DMX monitor, but it doesn't change.
I share your pain, however I have spend a lot of time building library's for various applications to interface with Lanbox (node.js, Bright Script etc) and so I know everything there is to know about Lanbox (including the bugs)
you have found the correct ref docs
you need to connect via TCP
after you connect it will ask for a password , send this , it is default 777
then to edit channels direct you need to look at the command
#C9 ChannelSetData
make sure you check out the command
#65 Common16BitMode
as a lot of the docs ref 16 bit mode but when you connect it will be in 8bit mode so if you need int above 255 you have to set it into 16bit
let me know if you need more help, when i do lanbox training it takes a few hours to full explain how they work so its understandable if you are totally confused
I was able to make a working HID USB stack on my "StartUSB for PIC" board for the 18F2550 microcontroller. I based it on one of the MLA libraries, which was made for the 18F45K50 (MLA 2018_11_26, hid_custom, picdem_fs_usb_k50.x), but I converted it to work with the 18F2550 (there might have been easier ways, but only learned to work with PIC about 1 month ago). On the host side, I'm using LibUsbDotNet (also here, there might be easier ways - the documentation on this library really sucks) on a Windows 10 machine.
I'm using the HID class, full speed, and all seems to work. Although, I get some random errors on the host PC (see below), but doing one close/re-open cycle on the host side when getting the error is kind of solving it. Dirty, but it works. So I kind of ignore this now.
Win32Error:Win32Error:GetOverlappedResult Ep 0x01
995:The I/O operation has been aborted because of either a thread exit or an application request.
I'm not an expert on USB (yet). But all examples I'm seeing are based on 1) you send first a command to the device and 2) then you retrieve the answer from the device. I did some performance tests, and see that this indeed shows that I can do about 500 cycles/second. I think that is correct, because each cycle, sending command and retrieving answer, each takes 1 msec.
But do I really need to send a command? Can't I just keep reading endlessly, and when the device has somthing to say, it does send the data in an IN transaction, and when not it ignores which creates a timeout on the host side. That would mean that I can poll at 1000 cycles/second? Unfortunately, I have tried it by changing my implementation on the PIC, but I get very weird results. I think I have issues with suspend mode. That brings me to another question - how can I make the device get out of suspend mode (means that not the host, but the device should be triggering this event). I have searched the MLA library for command such as "wakeup", "resume", ... but couldn't find anything.
So, to summarize, 2 questions:
Conceptual: Can I send data from device to host without being requested for it by a command from the host?
For PIC experts: How can I have a device trigger for a wakeup from suspend mode?
And indeed, the answer is Yes on the first question.
In the meantime, I found another link on the web that contains a Visual Studio C# implementation of a USB library including all the source files.
If you're interested, this is the link
This C# host implementation works as a charm. Without sending a command to the device, I get notified immediately if a button is pressed. Great!
It also proofs that my earlier device implementation based on the original MicroChip MLA, is 100% correct. I stress tested the implementation by sending a "toggle LED command" as fast as I could, and I reach 1000 commands/second. Again great!
I think that LibUsbDotNet isn't that perfect after all. As I wrote above, I get rather unstable communication (Win32Error). But with this implementation, I don't get a single error, even after running for half an hour # 1000 commands/second.
So for me, case closed.
In my current scenario, I'm using NETLIGHT Pin (Pin no. 64) of SIM800 module with my PIC microcontroller to know whether my module is registered or not?
This way I built the circuit. Just I removed LED from VBAT. Then I connect collected of NPN transistor to pic micro input PIN.
I want to know whether any easy way using AT commands to find network registration status of SIM800?
Unfortunalty it's seem not to be really possible (or in fact detecting this state in only one way)
I use SIM800 and let it run for hours and I have seen many cases of network loose, while the AT+CREG? continue telling everything is OK.
Also, even with network down, the SIM800 continue sending you the name of the operator and the strengh of the signal.
The only way I've found is to monitor the serial port: when the SIM800 loose the network, it sends two messages:
+PDP: DEACT and
+SAPBR 1: DEACT
I suggest you to have a look at the document "SIM800 Series_AT Command Manual" and especially the chapter "19.3 Summary of Unsolicited Result Codes". You'll find +PDP and other interesting code (like under-voltage warning, DNS failed...) and see some of these messages are not linked to AT command.
From the manufacturer's documentation:
I'm writing a GUI-based app in VB.net that talks to a LambdaMOO server via telnet, sends commands to display the object hierarchy, then parses the output and creates a visual representation of the object hierarchy.
So my question is: is there some kind of "telnet client" class for .NET to simplify the sending and receiving of data, or do I have to write my own using the socket API?
Does Mono have something like this?
Barring an easy solution, does anyone have a good tutorial they can point to for telnet client programming in VB.net?
Ok, I had a similar issue and ignoring all security complications and the like, wanted to TELNET from a VB initiated connection to a remote device and do stuff. I concur that the whole negotiation process is a hellish thing to do but once you've worked it out it's actually pretty simple to implement. I decided not to stop because I kept reading things that said it couldn't be done when it clearly can be done if you can write and read 1's and 0's into/from a network stream.
The code in the link below will initiate the connection and get you through to actually exchanging clear text information over TELNET. Given the example of sending a username and password combo shows how to read and write to the connection.
Big tips - initially have a nice big textbox or something to trap everything that comes into the buffer (variable returndata). This will help you diagnose problems. Also check on my blog there how to do this without the textbox blinking like a flashing thing. Once you've done all that and you know your script is reliable, trun off any screen updates and it will whizz through rather than take an age.
Apologies for the really dirty code and the crappy website layout.
http://myhead-online.blogspot.com/2009/05/vb-net2008-express-telnet-to-sun.html
The telnet protocol is basically just the usual TCP protocol, with a bunch of optional stuff that you probably won't need to implement. So you'd open a socket and start sending and receiving data with the socket stream interface.
Give it a try with the regular socket API, you'll probably find that it's quite straightforward.
just a suggestion. you may try to program your vb application to execute an existing telnet application in batch mode.
here is the link for your reference. refer to 7.3 Using Plink in batch files and scripts. Hope it helps.
You can grab one of any number of libraries to use. Here's one library:
LINK
For others try googling something along the lines of: library telnet mud .NET
Lastly, there are any number of opensource MUD/MOO/MUSH projects open at any time who are willing the share ideas and looking for people to help with projects.
I had my trials with telnet. You've to use tools like wireshark in conjuntion to figure out what commands needs to be initiated. I did find communicating with my unix box quite a challenge. For one thing you must know your telnet instructions. You might find it difficult to determined the state of the application - whether it is logged in or not innately. You'd have to formulate your own logic for it.
Another thing you'd have to do is parse the bytes returned by telnet into commands or instruction data i.e. you have to know if the bytes received is an instruction or some other thing it is trying to send you. Here is a ref that would come in handy.
First I suggest you start using the wireshark tool and get the communications send to and fro manually as well as via application.
From the LambdaMOO end of things, if you have wizard access or are friends with someone who does, you can have the MOO give you the data over another protocol that you might be able to work with more readily, such as HTTP. All you need is an object on the MOO with a do_login_command() set to handle requests, and then use the listen() builtin to get that object to listen on a given port. As long as a protocol doesn't require anything complex SSL, it's fairly easy to code up on the MOO end. So that might be worthwhile if VB.net has easier handling for HTTP etc.