I just finished coding a USB relay board to open and close 2 relays. First time doing any kind of .DLL programming. But now I need to code two USB bar code scanners on the same PC.
First I need to know which one of the scanners is being scanned.(I'm calling it -scan in/scan out)
And Secondly I need to capture the string to check against a database, but doing this without the scanner influencing any other program running, like if I'm focused on notepad while scanning, no text should appear on notepad.
Any info will be appreciated and Some Sample code even more.
Most barcode scanners behave like keyboards: you can use several at once, but finding out which one is doing what is not easy. I think the easiest way to do what you want is to use 2 cheap computers such as a Raspberry PI, plug a scanner on each ones and send codes to your application though IP. Considering the price of a barcode scanner, the price of 2 PI shouldn't be that much.
Normally you can program the barcode scanner with a prefix and a suffix code. For example a barcode like 123456789 get a prefix likes #S and a suffix likes #E when you scan a barcode, the barcodescanner sends #S123456789#E so you know the start and the end of the barcode. For the Second barcode you program de prefix en suffix with an other code for example #Q and #W so the second barcode scanner sends #Q123456789#W
Related
I am transmitting and receiving data using aux cable and GNU RADIO between two laptops.
I have implemented DQPSK using PSK mod block.
The problem is that while receiving I have to provide a delay, some integer value e.g 0,1,2 etc.
It is different every time.
Is there a way to dynamically check for the right delay value or any other workaround to this situation?
I have written 'start.' at the start of data being transmitted and 'end.' at the end.
I have to give a demo for this project and I dont want to manually change the delay at runtime.
I cannot find the .cc file of file sink in GNU RADIO, I can change the C++ code according my requirement but there is no such file.
Below is the screenshot of the grc file on the receive side.
Any help will be appreciated.
Since there's no way for the receiver to know when the transmitter started transmitting, it decodes stuff before there's actually anything to decode.
In essence, you need some kind of preamble or so to tell your receiver when to start – side effect of having something like that would be that you could correct some things (the two sound cards don't share the same oscillator, which leads to a symbol rate offset, and a center frequency offset).
You basically added that framing - your start. and end. strings.
I cannot find the .cc file of file sink in GNU RADIO, I can change the C++ code according my requirement but there is no such file.
It's in gr-blocks/lib; however, you shouldn't modify the file sink. Really,
I'd recommend you take the time to go through the guided tutorials, use gr_modtool to generate a general block which has a state machine that looks for the bits of your start string and drops everything before and including those, and then passes everything till it sees the stop string. That all can be done with a single state machine, and a bit of python or C++ code.
The device is a label printer. It can be connected to via bluetooth and USB. I would imagine it is running some kind of linux, as it has a fairly complex interface/screen, but am not sure. In fact, this is something I would like to determine. But my goal is to get a shell, or some kind of 'meaningful' connection through which I can send commands/data which will trigger print events by the printer without using the manufacturer's software
Connecting to the device in ubuntu via USB creates /dev/usb/lp0. I tried connecting to this using python's serial module, but it couldn't connect to the serial port.
Via bluetooth I was also able to connect, using hcitool scan to get the device's MAC address and then rfcomm to connect (using this approach) . This created /dev/rfcomm0, which I was able to connect to and send data to using python.
Is it feasible to mimic the data normally sent over usb/bluetooth by the manufacturer's software to print without the software? I assume getting this would be possible by 'sniffing' data sent over bluetooth while a normal print command is sent by the manufacturer's software (although I suppose there's no reason it would look intelligible to a human).
If this kind of mimicry is possible, I am wondering whether simply sending the equivalent data over bluetooth, for example, would result in a print event. So far I have no reason to believe that data I send via the bluetooth connection is not being received, but I have yet to get any kind of response (data or physical) from the bluetooth connection.
Any advice/suggestions on how I might achieve my overall goal would be appreciated
This is certainly possible (sorry for the answer 6 years later, but hopefully this will help anyone later in need). I have a similar problem and this is how I solved.
I have a MHT-P80F thermo printer. I figured out in settings that it supports a protocol called TSPL. These are the instructions you need to send to a printer and tell it to do either raw text printing, or even bitmaps.
All you need to do is to construct the correct bytestream (in mostly human-readable ASCII) and send it to /dev/usb/lp0. I have not tested it via bluetooth but I assume it should be similar.
For example, if you want to print out a "Hello World", these instructions will suffice:
CLS
SIZE 80mm,50mm
GAP 5mm,0mm
HOME
TEXT 0,0,"0",0,1,1,"Hello World"
PRINT 1
Each line is separated by a "\n".
Explanations (more could be found by searching TSPL):
CLS Tell the printer to clear all previous staged commands.
SIZE Tell the printer the size of each label (width, height).
GAP Between each label there's 5mm space without paper.
HOME (Re-)locate the paper roll for a new print.
PRINT Start printing of 1 copie(s).
Note these instructions are for the use of discrete labels. For a whole paper roll it might be different. TSPL implementations on different printers may differ, so you might to experiment a bit.
Generally, if you can print a bitmap, then you can print virtually any document (e.g. using PIL in Python or Jimp in Node.js to generate an image beforehand). So here's the most useful BITMAP command:
BITMAP 16,24,40,256,0,<BYTE STREAM>
where
16: the starting (left most) X coordinate for your bitmap
24: the starting (top most) Y coordinate for your bitmap
40: the width of bitmap, in BYTES (see below)
256: the height of bitmap, in DOTS
0: mode of print, 0 being overwritting anything in that region
and <BYTESTREAM> being the binary data(black/white) of this image, from left to right and from top to bottom.
The bitmap width is given in bytes, so each byte represents 8 horizontal continous dots in the image. The highest bit 7 being most left, the lowest bit 0 most right. So if as in example we write 40 in this parameter, the image would be 40x8=320 dots in width.
The bitmap height, on the contray, is given in dots.
Most such thermal printer have a DPI of 203. This is an interesting start point to investigate into: 203/25.4 = 7.99, or rounded as 8. So for the printer, each 8 dots equals 1mm. In the above example, X=16 and Y=24 (both in dots) corresponds to starting location X=2mm and Y=3mm.
And finally, you generally do not need to inverse the color of this image. In BITMAP command, a 1 in a bit means correctly white or non-printed dot, and 0 means the black or heated dot.
I am not sure about bluetooth but for USB printing you can use the cups library (licups) and use the APIs to do the priting. It uses IPP protocol. Usually cups uses a .ppd file specific to the printer (which contains the details about the printer) for installing it. For new language versions such as PCL5, 5e, 6 etc there are generic ppd files that can be used to install any printer that uses the respective language
I require my app to Scan barcode automatically , i have the barcodes, i have the app required, how can i make the App read physical bar codes using automation in appium,
In manual i can scan the code by pointing out the camera to an bar code.
I dont know how to do it while executing an test suite.
i got idea of placing Mobile device on an Stand, tripod and placing barcode in front of it.
But the problem is we can test only one barcode. i want to run for about 100-200 barcodes ans see app performance does not decrease, can any one suggest some ways?
This is a very interesting case. If you really want to test your app scanning the bar codes through camera then I think instead of looking for a solution through appium you have to look for a solution to exactly match your manual process.
You can click scan button using appium(I assume) - for example you can write a script to click on this button every 10 seconds.
Challenge is to point the camera to the next barcode as soon as first scan is complete. Possible solutions- I believe that all the bar codes can be captured in a file in a pc. Copy these bar code images in a ppt or using any other program so that these images can automatically displayed one by one.
Put your device in front of this pc as you are already planning to use tripod stand etc. Focus them on screen(may be first time you might need to do all these adjustments). Run your script. Do some trial runs. Synchronize the process with correct time outs. I think this should be feasible though really not the best way to automate this scenario.
I haven't tested it, but this blog post can be your answer http://www.mobileqazone.com/profiles/blogs/simulating-camera-in-android-emulator. If not, you can try bypass it by creating API to upload an image to your server instead of reading it from the camera. I think the impact on your QA will not change dramatically (besides, it's very easy and fast to check that part manually)
We do have an app that scans plenty of items such as bar codes plus tracking the dimensions of objects through the camera.
I read the idea of synchronizing images into a slideshow which is absolutely hilarious. The way I do it, is by using my own node server app with websockets that will toggle images through http requests. When this app is hosted in a laptop/ipad positioned exactly in front of the AUT, the test will have full control on which barcode to be shown at particular time frame.
No synchronization required at all and does the job.
It is a modified version of https://github.com/JangoSteve/websockets-demo
I have a bar-code scanner with USB interface, so it appears as an HID.
There are reasons why I must breakpoint on the first character.
That brings my Delphi IDE to the front, it stops on the breakpoint and the rest of the bar-code is injected into my code as if it had been typed front the keyboard (which, in a way it has, as the USB scanner is just another HID).
Is there any way to avoid this? Or to add an initial check as to the source of the input?
It annoys me so much that I am now looking for a scanner with an RS232 interface.
The problem is that HID "devices" send information back to the computer in packets known as "reports".
In the case of a mag-swipe, or bar-code scanner, the "report" contains the entire number.
Which is to say, you don't receive reports character-by-character, but the entire string at once. (In the case of a mag-swipe, you will receive all two, or three, tracks in the same report).
So your code doesn't break "on the first character", it breaks "on the entire report". The fact that the remaining characters are there you can think of as a bonus (if you don't want to look at them you don't have to). But you won't be receiving any more "reports" for subsequent characters.
i cannot imagine any reason why you wouldn't want to know the bar-code at once. But most mag-swipe and bar-code scanners can be configured to emulate a keyboard, rather than a generic HID device. In that case you will receive multiple WM_KEYDOWN messages.
sorry for this little bit strange title, didn't found a better one..
I've got the following situation:
I have a PC with an RFID reader connected via USB.
I now need a program which pops up when ab transponder was scanned the the RFID reader and shows the scanned value. (The reader just simulates keystrokes)
Problem: the value of the transponder is something like 0001230431, and I can't change it. (To prefix a hotkey combination or so)
So I have thought about using a global keyboard hook, check if three zeros where typed in, capture rest of data and when the 10 digits are complete, call the application through an automation object and show the number.
But I'm not very exalted about using a global keyboard hook. Many AV programs don't like them very much, they are not so easy to handle with Delphi and I guess that's not very resource-friendly for such a little task...
So I'm looking for an alternative solution...maybe somebody has an idea?
Big thx!
ben, you can use the RegisterRawInputDevices and GetRawInputData functions.
first you must use the RegisterRawInputDevices function to register the input device to monitor and then you can retrieves the data from the input device using the GetRawInputData function.
Check theses functions too
GetRawInputDeviceList retrieves the list of input devices attached to the system.
GetRawInputDeviceInfo retrieves information on a device.
Why not make sure the Delphi app with a text edit control has focus before the scan is done? Then the keystrokes will go straight into your Delphi app.