EEVblog #692 - Digilent Analog Discovery Review

[jaxbird]

...
I suspect they are hoping that third parties will do something and contribute it to the bazaar. One starting point mighe be http://blog.redpitaya.com/?p=501
...

Notice that the example shown is based on just 20 measurements from 1kHz to 10MHz, it could be for simplification or add to the evidence that there is an issue with speed.

Would be interesting to hear from anyone owning the unit.

[tggzzz]

...
I suspect they are hoping that third parties will do something and contribute it to the bazaar. One starting point mighe be http://blog.redpitaya.com/?p=501
...

Notice that the example shown is based on just 20 measurements from 1kHz to 10MHz, it could be for simplification or add to the evidence that there is an issue with speed.

Would be interesting to hear from anyone owning the unit.

What evidence is there? You have only supplied unjustified assertions.

I'm listening, and don't expect a fully justified watertight answer - even a hint as to the reason for your assertion would be helpful.

[boffin]

I was happy enough to pick one up used off a local classified site.  They're going on ebay for nearly $200, and I got one with a little parts kit and breadboard for $100.  Picked up some cheap scope probes from China as well, and will order the BNC adaptor from Digilent tonight.

So, keep your eyes open if your local uni/comm college uses these in their teachings.

[Quentis]

Hello,

I have bought analog discovery recently and a I tried it in loopback mode and I applied a 100mV (and 200mV) DC to the waveform generator and I measured 96-97mV (and 196-197mV) in the oscilloscope. After that I measured the AWG with a multimeter in 200mV range (0.5% error) and it showed 95.4mV (94-96mV) so it seems the AWG has a nice offset. In terms of bits: let say low gain is 1.25V * 2 = 2.5V and (2.5V / 2^14) = 0.15mV so it means 3-4 bit error which means the effective number of bits are 10-11.
Have you experienced similar to this or is there any problem with my calculations?
It is possible to calibrate the device so I will try to get something more precise stuff and do it. I just wanted to know if this is common or other units are more precise. (the factory calibration page is filled in of my unit so it seems strange)

Best regards,
Quentis

[tggzzz]

Yes.

http://lmgtfy.com/?q=analog+discovery+calibrate

[Howardlong]

Quick note regarding a fault that developed yesterday on my original Analog Discovery.

This is still a really useful device, so although I upgraded to the AD2, I still regularly use the AD1.

At first it was an intermittent micro USB connection, then after a further half dozen or so re-insertions as I tried to understand the nature of the fault, it failed permanently.

So I opened it up and of course three of the five pads on the micro USB receptacle had separated from the board, including D+, D- and Vcc. To fix the D+ and D- is just a matter of scraping the tracks and adding a short couple of millimeters of link wire. The vias for Vcc underneath the receptacle so I removed the receptacle completely to take a look. There are large pads on both top and bottom of the board underneath the receptacle next to each other and connected with a few vias, so you can safely link the Vcc connection round to the reverse of the board.

After testing the repair, with a micro USB plug inserted, I added a tiny blob of superglue to the USB receptacle's pins in an effort to alleviate too much strain in future on the repair rework.