I'm using a DSP to control a sensorless brushless DC motor, The DSP is on a board which has a parallel port and a jtag connection (it's an eZdspTMS320F2812). What would be the best way to communicate between a PC application and the DSP as it was running? Ideally I'd like to have a GUI program with buttons like start, stop, accelerate, decelerate... but I've never done anything like that before. Which ports and method would be easiest to use?
Thanks
You can also use simple RS232 communications. I use always because it`s cheap and easy to implement.
The RS232 transceivers are very cheap (like MAX232 from Maxim-IC), and easy to use. Also they come in many packages like DIP or SOIC for example and can be found almost every electronic shop.
You can use any USART from your microcontroller to link with MAX232. Then, using a PC serial-usb converter (or if your PC does have a serial port it`s easier), you can use serial port programming from any programming language to develop your desktop application.
After that, all you have to do is create a protocol to exchange data between your PC programm and your DSP (some simple commands to start, stop and change motor direction for example).
Good luck in your project.
The parallel port is probably the easiest route. Depending on what OS and programming language you are using you should be able to find example code or libraries to support bi-directional communication via the parallel port. Since you have a small set of commands that you might want to send to the DSP board then you can probably just send a single character to the board for each command, e.g. 'R' = start, 'S' = stop, etc.
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Hallo this is my first post here.
I'm currently doing my internship at a company that uses twincat 3 programs for automation in conjunction with a yaskawa robot system. The assignment I received is to expand the simulation software they currently use to simulate the plc software to also be able to simulate the yaskawa interface so they can test if changes in eithers software causes issue's in the other without having to upload the program to a PLC. I've been looking online and found a couple options but I'm curious if I missed some other options or if the options I've found will not work.
The options I'm currently considering are.
using the ethernet port on the simulation pc to connect to the Yaskawa controller. I've found a driver(https://infosys.beckhoff.com/english.php?content=../content/1033/el7031-0030/1036996875.html&id=) that will allow the user to make an ethernet port on their pc function in real time so I theorized It might be possible to then directly connect the computer to the yaskawa controller so the user would not need to upload the software but have the PC act as a PLC instead.
Use ROS to simulate the robot. there are libraries for ROS industrial to program and simulate a yaskawa robot. It would require using 2 computers or using a virtual machine as ROS is used best on an linux system. Only problem is I can't figure out if the ROS simulation can use regular yaskawa jobs and functions or if it can only the adapted ones programmed in ROS.
Use motomans simulation software motosim to simulate the yaskawa robot. Seems like an obvious solution but can't figure out if it's possible to have it communicate with twincat3 however I might have missed something.
write a twincat 3 software that emulates a yaskawa interface. I consider this a last resort if all else fails. It would require the code be updated each time something about the yaskawa software changes which is not ideal for quick testing.
I'd really appreciate any suggestions or additional information more experienced programmers might have.
Is it possible to access external hardware without using a driver, i.e. not having the driver abstraction layer in between program and external device?
Can you use a device by implementing your own driver-like controlling/handling directly in your program code?
I'm trying to understand a program that implements a Modbus protocol and some very specific Modbus configurations. Now I don't know how exactly it communicates with the Modbus devices.
It looks to me that this is very similar to what a driver does.
But can it even communicate DIRECTLY with the device without having a driver installed?
Yes, there are several micro-kernel OS's that always configure this way -- drivers are entirely implemented outside of the kernel.
The first thing you likely need is to get access to the device's registers; typically performed with mmap(), you may need to dig around a bit to find the right settings for cacheability, etc...
Second problem is interrupts. Unless you are running something like QNX, you won't have a way to have interrupts signal your program directly. You will probably have to turn them off and poll the device periodically.
If you are using linux and need io ports (inb, outb, etc...) man ioperm for more information.
We need to do some stress testing of our system, and we would like to be able to simulate non-ideal situations: things like latency, jitter, etc. In particular, we would like to simulate behavior of data over a cellular network.
Do you know of any hardware/software/both solutions that would work?
Thanks
Ideally you would get some idea about parametrization from a real simulator like ns3. Or write one yourself.
Additionally you could use the Linux kernels built-in QoS stack which provides the netem module which can be used for these purposes. netem provides network emulation functionality for testing protocols by emulating the properties of wide area networks. The current version emulates variable delay (jitter), loss, packet corruption, duplication and re-ordering. It supports distribution based opteration or you could script it to change certain values during run time.
Wifi card with an older access point/router, simply take the test station to the edge of the range and you should be able to reliably cause the connection to fail and reconnect. Only reason I sugest an older model is that the range generally weren't that fantastic on the older "802.11b" stuff.
But other than just being a lossy connection, I am not sure you'd be able to use this setup to test certain characteristics of a cellular connection, but it should work.
If you are in the US, an iPhone on AT&T would probably do it..
Probably need something along the lines of:
USRP Board, OpenBTS, TrixBox/Asterisk
You can check out OpenBTS(http://openbts.sourceforge.net/) and see if it will do what you need. You could have it use the USRP board as a tower, then use it similar to a loopback. I do know that the above combination will allow phones to connect to it like a cell tower(See BurningMan/DEFCON 18), so in theory it should allow you to broadcast out to saturate the spectrum.
OpenBTS-UMTS include 3G data http://openbts.org/w/index.php?title=OpenBTS-UMTS
You can download and compile on Ubuntu 16.04, there is some issue with dependencies on Ubuntu 18.04.
About hardware, i used both Ettus USRP N210 and X310.
I am communicating across USB, using a proprietary protocol, with some custom hardware I've built. I have a GUI that handles all the communications/interaction with that hardware and a (C#) DLL which exposes all the relevant USB functionality. I need to write a LabVIEW driver (VI) for communicating with the hardware. My thought is that I just use LabVIEW to open up my GUI and have a socket with which I expose all the relevant control to LabVIEW with. Is it possible to open a socket in LabVIEW and communicate with my GUI? Is this a bad approach or should I just try and make LabVIEW invoke the DLL and handle the hardware control instead of my GUI (polled communications, solicited/unsolicited commands, etc)?
IS there a reason you want to use your GUI only? In terms of time, I would say build a good front panel in LabVIEW and just communicate to the hardware directly using the DLL. Adding the GUI is just an added layer of complexity which might be difficult to maintain later on? Why not do everything in LabVIEW if you can?
Yes, LabVIEW supports sockets using both TCP/IP and UDP.
You should be able to create a program/service that continually runs acting as TCP/IP server. You can send commands and receive responses as strings. If you need to pack data, you can use the flatten to string command.
Essentially, your application should be structured as a loop running the TCP/IP server, and another loop that actually communicates with the instrument. This might change if you need to get data back from the devices to your TCP client. A producer consumer model, if you will :)
To get you started off, open up the NI Example Finder (Help -> Find Examples) and browse to Networking->TCP and UDP-> Simple Data Server.vi
It depends who is going to be using the LabVIEW driver and for what. If you're handing over this hardware to someone else who is going to want to create their own application(s) for it, they would probably prefer to talk directly to the DLL rather than go through your GUI. If it's more about automating your existing software from LabVIEW to do testing or repetitive tasks on the hardware, for example, then driving your GUI from LabVIEW might be less work.
I want to make a Wi-Fi controlled robot.
After a lot of research, I decided to use an Asynclab's BlackWidow which was the best way for me to do this.
But unfortunately, this product is out of stock everywhere!
I ordered one on roboshop and I got the message 25 days later: Sorry, this product is sold out.
So, I'm looking for another microcontroller with a Wi-Fi interface.
I also need this very quickly (because it is for a school project), and it must be as cheap as possible.
I've been looking all the day but I couldn't find something as "good" as the BlackWidow.
You can get the WiFly shield from sparkfun.
In the past I have used a Linux router (with positive results) with Gargoyle (OpenWrt based) as a wireless gateway and communicate with it through a serial port, as most of them attach a console to the serial port so that you just have to send the command and '\n' to be executed. With the cURL libraries should be fairly easy to communicate without much effort with whatever you want.
You have the power of Linux and a pretty powerful CPU, can configure it through the command line or web page, and most important, a lot of routers are much cheaper than the 'BlackWidow'.
The one I used is the Fonera+ (unmounted doesn't take much more space than an Ethernet Shield) and used to cost around $28 although it is now deprecated, but some other routers from Linksys, TP-Link, etc. are also compatible as stated in the OpenWrt Compatibility Table.