Analog Discovery 2 vs new Raspberry Pi 4 (4GB)

[FloMai]

Hey guys it was announced that with the new RPi 4 the connection problems with AD2 where solved, but it still seems not stable ERC: 0x2.

Any suggestion how to improve setup?

Power supply is 5V/3A and AS2 is connected to USB 3.0 port.

Linux version 4.19.75-v7l+ / Raspbian GNU/Linux 10 \n \l

BR  

 

[JColvin]

Hi @FloMai,

I apologize for the delay. I updated my Raspbian desktop to the same edition (4.19.75) but I am able to detect and run the Analog Discovery 2 with a Raspberry Pi 4 Model B without. Could you attach a picture of your setup? Otherwise, I might recommend trying an external power supply. @attila do you have another idea of something this user might try?

Thanks,
JColvin

[attila]

You may also try to use powered USB hub...

[FloMai]

Hi,

I have done lots of testing, after >one day triggering logic signals with low sample rate connection fails. Also when I just trigger one channel, so I guess its not a thing of to many data.

What I already tried is:

- different external power supplies (1-3Amps)

- change from USB3.0 to USB2.0 port ( in the beginning it seemed that's stable but...)

- operation without keyboard and mouse load

For me it looks like there is still some problem in HW, may USB of RPI is not fully USB compliance, I will go on with testing...

 

could you do some long term test?

 

BR Florian

 

[attila]

Hi @FloMai

I have tested RPi4 for about week.
Running continuously for 1-2 days combinations of USB 3 and 2.0 ports, with hub and without it.

The only issue I noticed was with hub connected to the USB 2.0 port. This could have been an issue with the hub. I have had problems in the past with specific hubs even when connected to the PC, random disconnects with some devices...

 

[FloMai]

Hi Attila,

thanks for the reply, I have tested now with USB 3.0 hub (Anker 7-Port) and connection failes anyway after some hours, I doublechecked with 2nd setup (RPI4 and AD2) and same failure.

how is your setup in waveform, did you run a trigger over days or just run scope?

can you open logic register, add all 16 channels and set trigger for all in long term?

 

BR Florian

[attila]

Hi @FloMai

I have used the Logger tool, which uses the scope inputs to stream data.

I will repeat the test with Logic Analyzer.
To have similar conditions as you had, about what trigger rate did you have for the Logic Analyzer?

[FloMai]

I have tried several sample rates, even when I set 2s/200Hz and buffer 1 connection will fail.

Would be great if you test this or even faster sampling on your obviously stable setup, Thanks!

[attila]

Hi @FloMai

Sorry for the late reply. It looks like event the RP4 has problems with the AD2. 
In my earlier tests where it was running for 1-2 days, the communication rate with the device was only about 1/second.
Repeating the test with ~100/second rate, I get 0x02/timeout error after about a day with USB 2 and 3 ports, and with USB hub every 6-12 hours.

[FloMai]

HI @attila

ok thanks, is it possible to program a connection check or reconnection loop via script?

Or has anybody programmed some labview application with no connection issue?

Do you think with 1/second it will run over long term, I don't need a high sampling?

[attila]

Hi @FloMai

The issue is that the USB packets get lots, the communication gets out of sync.
This should also happen with custom application/script, but with this it is possible to reconnect to the device.
I will try to add to some retry or reconnect mechanism to the library.
With lower communication rate, ~1 per second it was running for me 1-2 days without any issue.