AR488 Arduino-based GPIB adapter

[rockstedy40]

Thanks WaveyDipole for your response and all your efforts on the software!

[Gertjan]

Hi WaveyDipole,
A happy AR488 user here. Many thanks for all the hard work you put into AR488! 

A suggestion for a small improvement:
Several times the subject of problems with the ++ver string came up, as discussed here:
https://www.eevblog.com/forum/projects/ar488-arduino-based-gpib-adapter/msg4512557/#msg4512557

The problem is that KE5FX requires 'Version 6' and EZGPIB requires 'GPIB-USB' in the version string.

So far the solution was that KE5FX and EZGPIB users had to change the version string with ++id verstr and  ++savecfg.

I looked at the version string of my Fenrir GPIB-USB adapter (a Chinese Prologix clone): “Fenrir GPIB-USB 1.0 (Prologix version 6.0 compatible)"
It is clever that all required character sequences are present in the string.

Would it be a good idea to do the same thing for AR488? And make the default ++ver string something like: "AR488 GPIB controller, ver. 0.51.18, 26/02/2023 (Prologix version 6.0 GPIB-USB compatible)".

Putting the character sequences required by KE5FX and EZGPIB into the default version string would save new users a lot of searching before finding the ++id verstr solution.

Regards, Gertjan.

[coromonadalix]

I would put like this, the other is way too long for device manager  loll

"AR488 GPIB, v0.51.18, (Prologix version 6.0 GPIB-USB compatible)"

[WaveyDipole]

Happy to include that. I added the ++id verstr command so that users could change the string as requited. If the software changed, it had the flexibility to be changed. If any other software required some other string, then that could be configured as well. However, if it works with both KE5FX and EZGPIB, then I am happy to make the string proposed by coromonadalix the default and extend the string variable to 64 characters (63+null) as it would probably cover most use cases.

[dietert1]

How do people use the SRQ auto poll?
As far as i understand the SRQ:... message may arrive at any time. What is a good scheme to use on the host side in order to avoid confusion? Don't use the GPIB controller while waiting for an interrupt?

Regards, Dieter

[Gertjan]

I found another source for GPIB connectors.

The Chinese manufacturer Fuyconn is now selling its connectors on AliExpress.

The quality is a bit more "Chinese" than the A-brand connectors, but is still very decent, and they work flawless.
I am happy with their look & feel:


IMG_2312__Fuyconn_GPIB_connectors-2000pix.jpg

Regards, Gertjan.

[dietert1]

Yesterday we got two 1.5 m GPIB cables from Amazon at € 20 each. I'd guess they are of chinese origin, too. I opened one of the plugs to see the cable shield. These cables are sold as new and appear to be very similar to those old ones offered elsewhere for more than double the price.

Regards, Dieter

[bingo600]

The Chinese manufacturer Fuyconn is now selling its connectors on AliExpress.

$17 in shipping for 1 pcs 

[Gertjan]

The Chinese manufacturer Fuyconn is now selling its connectors on AliExpress.

$17 in shipping for 1 pcs 

Yes, shipping costs are high, at least in the context of what is usual on AliExpress. But you are dealing with a manufacturer selling direct, not with the average AliExpress shop...
And the price of the connectors is low: $2,90. I ordered five, and paid less than when I had ordered connectors from Mouser or Digikey.

And I did get value for the shipping costs: The connectors arrived within a week. 

Regards, Gertjan.

[Gertjan]

For people who want even cheaper Chinese GPIB connectors:

Dutch Circuits Online forum member Peter_dtn found these: cheap GPIB connectors on Ali Express

Take care to choose "24p MALE SOLDER" to get the right model with PCB pins....

These connectors are cheaper, and also, for these the shipping costs are the usual Ali Express low price 
But I did not buy them, so I do not have any idea about quality... (I am still happy with the Fuyconn connectors)

Regards, Gertjan.

[rssenior]

Have just posted a further update (0.51.15) this morning that fixes a couple more bugs.
Still working on the MCP23x17 stuff.

I recall reading that recent MCP23017's aren't completely bi-directional.  GPA7 and GPB7 can only go one direction (output only). MCP23S17 (the SPI version) doesn't have that problem. See: https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP23017-Data-Sheet-DS20001952.pdf

[rssenior]

Over the last few days, I hacked together a "custom" AR488 using a Teensy 3.1 (3.3V with 5V tolerant pins) I had lying around along with SN75160/SN75161. I posted a github issue about it earlier today (https://github.com/Twilight-Logic/AR488/issues/37). After a ++mode 1 and ++xdiag 1 255, I am seeing DAV and SRQ only drop to 0.5V instead of 0V (the other control pins nicely go to 0V), and the GPIB bus side of the corresponding transceivers not going low (hanging around 2.8V). Does this sound familiar to anyone? If I remove the SN75161 chip, the Teensy is trying to assert 0V, so something about the SN75161 isn't letting it get them pulled all the way down. TE and DC are both low. AHA! The function table on page 2 of the datasheet say that when TE, DC are low, SRQ and DAV are in receive mode. DC needs to be high to test SRQ and TE needs to be high to test DAV.

[caiser01]

Got a notice from Digi-Key yesterday that the DIP version of the SN75160 is going EOL. The SMD version looks like it will still be available for now. If anybody wants factory-fresh DIP versions of the SN75160 on hand for prototyping, you may want to think about getting them soon.

https://www.digikey.com/en/products/detail/texas-instruments/SN75160BN/370217

[WaveyDipole]

Thanks for pointing this out. As demand for through-the-hole components continues to fall, suppliers have been reducing and eliminating their stock in favour of their SMD equivalents, so I guess this is not entirely surprising. Wroth being aware of though.

[WaveyDipole]

Have just posted a further update (0.51.15) this morning that fixes a couple more bugs.
Still working on the MCP23x17 stuff.

I recall reading that recent MCP23017's aren't completely bi-directional.  GPA7 and GPB7 can only go one direction (output only). MCP23S17 (the SPI version) doesn't have that problem. See: https://ww1.microchip.com/downloads/aemDocuments/documents/APID/ProductDocuments/DataSheets/MCP23017-Data-Sheet-DS20001952.pdf

Hmm, yes, table 2.1 on page 11. I hadn't noticed that. The chips are not high-Z either and power on the bus does reach the MCU board. I have, for now, abandoned testing these chips.

[Miti]

Got a notice from Digi-Key yesterday that the DIP version of the SN75160 is going EOL. The SMD version looks like it will still be available for now. If anybody wants factory-fresh DIP versions of the SN75160 on hand for prototyping, you may want to think about getting them soon.

https://www.digikey.com/en/products/detail/texas-instruments/SN75160BN/370217

I have been using the smallest packages that I can work with for quite some time. 0603, SC70, SOT, TSSOP, etc. If you want to do electronics these days, you have no choice but to adapt, and it makes no sense hanging onto the dinosaurs.

Cheers,
Miti

[Kean]

If you want to do electronics these days, you have no choice but to adapt, and it makes no sense hanging onto the dinosaurs.

Isn't the main purpose of building these GPIB interfaces so that we can continue to hang onto our T&M dinosaurs and boat anchors? 

[Miti]

If you want to do electronics these days, you have no choice but to adapt, and it makes no sense hanging onto the dinosaurs.

Isn't the main purpose of building these GPIB interfaces so that we can continue to hang onto our T&M dinosaurs and boat anchors? 

You don’t do nothing to those boat anchors, you use them as is to make something new or to learn. If you want to make something new, you’ll have to adapt. Not only that the old parts are disappearing but the new ones offer much more flexibility and performance. This adapter that we’re talking about is only used to connect to the boat anchors.

[coromonadalix]

If you want to do electronics these days, you have no choice but to adapt, and it makes no sense hanging onto the dinosaurs.

Isn't the main purpose of building these GPIB interfaces so that we can continue to hang onto our T&M dinosaurs and boat anchors? 

You don’t do nothing to those boat anchors, you use them as is to make something new or to learn. If you want to make something new, you’ll have to adapt. Not only that the old parts are disappearing but the new ones offer much more flexibility and performance. This adapter that we’re talking about is only used to connect to the boat anchors.

@ Miti  that's your opinion, not the same for others ... some "old" stuff where better in many ways ...  ''new''  doesn't mean better  since quality and durability in some case(s) are long gone

[dietert1]

For me the reason to make GPIB adapters was security. When i looked into the process table in my workstation and saw several processes installed by NI and whoever even when i wasn't using any of their stuff i wanted to become independent of that. No sniffing in our lab.
14 years ago i made some GPIB controllers based on XILINX CPLD with a FT245. They implemented only the basic bus handshaking, which means they require quite some library on the host to execute the usual GPIB transactions. Connecting two of them back-to-back one can transfer at 2 MBytes/sec.
Recently i made some STM32 based adapters with text interface to be used with a terminal program, much like the AR488. I am using it all the time. It can also support I2C ambient sensors, precision temperature monitoring with a ADS1256, SPI control of a relay scanner and a transparent RS232 connection. I want to use that for a setup with a Keithley 2182A nanovoltmeter.

Regards, Dieter

[Miti]

If you want to do electronics these days, you have no choice but to adapt, and it makes no sense hanging onto the dinosaurs.

Isn't the main purpose of building these GPIB interfaces so that we can continue to hang onto our T&M dinosaurs and boat anchors? 

You don’t do nothing to those boat anchors, you use them as is to make something new or to learn. If you want to make something new, you’ll have to adapt. Not only that the old parts are disappearing but the new ones offer much more flexibility and performance. This adapter that we’re talking about is only used to connect to the boat anchors.

@ Miti  that's your opinion, not the same for others ... some "old" stuff where better in many ways ...  ''new''  doesn't mean better  since quality and durability in some case(s) are long gone

I was talking about parts, you are talking about final products. For parts, you don't even have something to compare with in many cases. What do you compare an Altera Cyclone V (random choice) in BGA with, that come in DIP package?

[Miti]

For me the reason to make GPIB adapters was security. When i looked into the process table in my workstation and saw several processes installed by NI and whoever even when i wasn't using any of their stuff i wanted to become independent of that. No sniffing in our lab.
14 years ago i made some GPIB controllers based on XILINX CPLD with a FT245. They implemented only the basic bus handshaking, which means they require quite some library on the host to execute the usual GPIB transactions. Connecting two of them back-to-back one can transfer at 2 MBytes/sec.
Recently i made some STM32 based adapters with text interface to be used with a terminal program, much like the AR488. I am using it all the time. It can also support I2C ambient sensors, precision temperature monitoring with a ADS1256, SPI control of a relay scanner and a transparent RS232 connection. I want to use that for a setup with a Keithley 2182A nanovoltmeter.

Regards, Dieter

Agree, and let's not forget the price. Check the price of a genuine NI GPIB-USB-HS which in many cases does the same thing that AR488 does.

[Shonky]

I'm putting together the artag (thanks for the gerbers!) design AR488 v3 based around a ATmega32U4.

I've had a pretty good search through this thread but I'm not sure what the recommendations are for configuring the Arduino for 5V or 3.3V supply. It seems from the photos and a few posts 3.3V works fine and that's what most people are using in absence of directive.

However GPIB is rated up to 5.25V maximum so shouldn't we be using 5V IO where possible? The ATmega is only rated to Vcc+0.5V on its inputs.

It appears the J1 jumper on the Arduino Pro Micro simply bypasses the 3.3V regulator and runs the whole device at 5V when shorted.

So is 5V recommended where possible?

[T3sl4co1l]

TTL outputs only pull up to about 3.5V.  3.3V LVCMOS is actually a pretty good fit.

Tim

[mankan]

@shonky Maybe it could be a good idea to be pin compatible with https://www.eevblog.com/forum/testgear/open-source-gpib-adapter/