Touch Screen Interface for older Test Equipment? - Page 1
Forum section: electronics / testgear

author: Magnum
author_rank: Regular Contributor
timestamp: September 08, 2017, 12:07:17 pm
content: Hello,I have several "older" Test Equipment like Keithley multimeters and SMU, Agilent DAQ-unit and also a Keysight 34465A. I am using the trend chart of the 34465A quite often and so I was thinking about adding a touch screen interface to my older equipment to make them easier and faster to set up (esp. the Keithley 2440) and to get more information (like trend charts, histogram, statistics) out of them, too.I was playing around with Keysight VEE and Labview. It works, but you need a PC running for that. So the idea was to use a Raspberry with the 7" touchscreen attached. No keyboard or mouse necessary, screen is big enough to display data and charts. Price below EUR 100.Connection should be done via Serial or GPIB. The Voltnuts in Metrology use a Raspberry for datalogging, so getting the data into the Raspbery shouldn't be a big problem.The question is, which software / programming language to use for the data display. I don't want to start programming a trend chart, as IMHO it will take some time to have it completely functional and good looking. I found a software to run Labview on a raspberry (with the graphical user interface, no PC for running required,www.tsxperts.com), but i am looking for other alternatives.So does someone have an idea what to use? Is there anything available like a scaled down version of Labview that runs on a Raspberry? A programming Toolkit to display the data easily?Thanks,Magnus

author: texaspyro
author_rank: Super Contributor
timestamp: September 08, 2017, 03:10:40 pm
content: If you are adventurous you might want to look at Lady Heather. It runs under Windoze, Linux / RPI, FreeBSD, and macOS. It is written in C (90,000+ lines of code in there). It is oriented towards GPSDO / GPS / time and frequency devices, but the basic framework is rather general purpose. It can display plots of up to 15 different variables and can generate trend lines, FFTs, and histograms of any plot. Also calculate various statistics (MAX, MIN, SPAN, AVERAGE, RMS, SDEV) of any plot. There is support for touchscreen devices that appear as a mouse to the OS.The captured data is saved in a circular buffer (default 3 days at 1Hz) and you can configure the plot window to show any section of the plot queue. Input data can come from serial to TCP/IP connections. The latest (currently unrelased) version can talk to up to 16 or so serial / TCP ports.

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: September 08, 2017, 05:05:19 pm
content: I do remember seeing someone do a touchscreen conversion on a scope, I'll see if I can find the project.

author: Keysight DanielBogdanoff
author_rank: Unknown
timestamp: September 08, 2017, 05:09:51 pm
content: Here's one project, looks like it's essentially a nano sending SCPI commands:https://hackaday.com/2016/02/04/pimp-my-scope-touchscreen-edition/I did see another one that I couldn't find immediately where they created their own basic GUI as a sort of add-on screen with some customizable soft-keys.

author: Magnum
author_rank: Regular Contributor
timestamp: September 08, 2017, 10:12:51 pm
content: Thanks for the infos.@texaspyro: Lady Heather has quite some functionality, but doesn't look that nice. I'd like to have scrollbars, buttons for scaling etc.@Daniel: It looks cool what he did, but unfortunately he interfaced the nano with the keyboard bus of the oscilloscope. So that's quite some hardware hacking, esp. if you want to control several instruments. And it is not universal for other instruments.I am checking out now the solution from tsxperts, but it is not that powerful as the "real" Labview. The charts from Labview can be heavily configured and as all instruments I have come with drivers for Labview I don't even have to read the manuals for the SCPI commands. Interfacing with GPIB is also simple. A solution could be to use a cheap windows tablet for it (they start around 170 Euro with USB). I am not sure if I really want to do that, a raspberry solution would be nicer.

author: texaspyro
author_rank: Super Contributor
timestamp: September 08, 2017, 11:20:19 pm
content: Quote from: Magnum on September 08, 2017, 10:12:51 pmYep, ya' get what you pay forHeather is basically all keyboard driven... none of that new fangled buttony / scrolly / drop down menuy crap. And one monospaced font (in a few different sizes). The plots do have manual or auto scaling and centering.

author: Magnum
author_rank: Regular Contributor
timestamp: September 08, 2017, 11:50:50 pm
content: Don't get me wrong, I am using Lady Heather for my GPSDO and I like it.But I don't want to use a keyboard or mouse, just the touchscreen mounted next to the instruments. I have everything set up with my PC, but when I want to make a quick measurement I don't want to start everything first. That's why I use the Keysight 34465A so much, as it has the charts and statistics built in.It would be great to get it working with the raspberry for the most used instruments (e.g. Keithely 2000, Agilent 34401A etc) so it would be a cheap and easy solution for everybody to get the most out of their instruments.

author: texaspyro
author_rank: Super Contributor
timestamp: September 09, 2017, 12:48:50 am
content: One thing the newest Lady Heather code is an on-screen touch screen (you bring it up by touching the upper left corner of the screen). The F1 .. F9 keys will run a keystroke script file.Also you can scroll the plot area left/right or zoom it to a given point. You can also zoom the plot area to full screen by touching the plot label area.

author: KE5FX
author_rank: Super Contributor
timestamp: September 09, 2017, 02:46:27 am
content: Quote from: Keysight DanielBogdanoff on September 08, 2017, 05:05:19 pmThis fellow's project is really nice:Not every day you see someone running a spectrogram display on a 141T.

author: free_electron
author_rank: Super Contributor
timestamp: September 09, 2017, 03:04:35 am
content: Quote from: Magnum on September 08, 2017, 12:07:17 pmby the time you got a pi , the touchscreen , the power brick, the sdcard and all other crap , you could easily run an intel NUC ...