Anyone played with these cheap ($50) Zynq boards

[mac.6]

I have added the board support in buildroot:
https://github.com/m-chabot/buildroot/tree/zynq_qmtech

Note that since ethernet is on PL side, there is no network in linux unless you add the correct bitfile.

[FenTiger]

I ordered a few of these too. They took 10 days from order to delivery - not bad for China!

Here's what came in the package:

• The board itself, packed in bubble wrap and an antistatic ziplock bag.
  
• A 16Gb micro SD card, already in the slot, preloaded with Linux. It's not necessary to work through the getting started guide at first; you can just plug it in and take a look.
• A 5V wall wart - with an American plug on it, and I don't have an adapter. Doh! Not a huge problem though, since I have a 5V supply already.
  
• Mini USB cable.

There are no mounting holes. Are these things so price sensitive that they couldn't afford to drill four holes in the corners? Building anything real around this will involve using it as a daughterboard.

Decoupling is, as mac.6 says, minimal. There are no parts at all on the underside of the board; I expected at least a few capacitors near the power pins.

At power on, Linux boots in about 5 seconds. The board draws about 200mA while booting, dropping to 160mA once up.

Taking a quick look at the peripherals:

The micro USB port is connected via a CP2102N USB-to-serial chip to PS UART 1. Obviously this limits flexibility - it can't enumerate as a HID, say, or as multiple serial ports - but the data sheet claims that it runs at up to 3 Mbaud, so there should be plenty of throughput.

The Ethernet PHY is an IP101GA. It links up at 100Mbps, and I measured the throughput at 98 Mbps in both directions. Not too shabby! I didn't measure the latency.

I took a quick look at the IO headers too. The first observation is that there aren't many ground pins; maybe there'll be crosstalk between the adjacent IOs. There aren't a lot of power pins, either.

At least some of the IO pins appear to be routed as length matched differential pairs. Maybe it's possible to use them at high speed.  I haven't looked closely, though.

[slburris]

Now that a couple of you have had these boards for a month, do you think they are worthwhile to get over more commercial products, say the mini-zed or Cora z7?

[ralphrmartin]

In the end I got rid of mine, and bought a Pynq Z2 which looks rather more flexible, for 990 RMB.

[colorado.rob]

In the end I got rid of mine, and bought a Pynq Z2 which looks rather more flexible, for 990 RMB.

Great choice.  I have two of them.  Extremely versatile boards.  In the US, they can be had for 120USD from Newark/Avnet.

The one caveat with these boards is that the PL clock from the Ethernet PHY is glitchy unless connected to a switch when doing PL-only designs.  I think that's likely the case for all boards that use the same Realtek PHY.

[ralphrmartin]

Rob
perhaps you can help me with an issue I am having then! 
I've got a bitstream which includes a processor, and an audio IP block which just passes audio from line in to headphones (processor and audio not connected yet, to be done later, and the audio IP to be made more interesting).
Now, when I load the bitstream via JTAG, the audio IP runs just fine, and I can hear the passthrough.
However, if I load the bitstream from Python as an overlay, I get no audio output.
I dont really understand why the same bitstream behaves differently in these two cases.
(I've got other bitstreams up and running OK to mess with leds and switches from Python).
Any insights you can offer?
Thanks, and sorry to others for going a bit off topic...
Ralph