Mono Audio Output Pynq z1

[Payam]

I am trying to generate a signal off the audio output of pynq z1. For a while, I had a board and it was working fine. Then suddenly it stopped working. I tested everything is ok. I send the right PWM signal to the output. But no analog signal is detected from the audio output. I thought maybe the board hardware is damaged. So I buy a new board. But still I cannot get any analog signal from audio output. Any clue what may be the problem?

[engi]

is that a buffered output followed by a RC-filter ? Can you measure the signal? Can you chipscope it?
 

[Payam]

The FPGA probe show correct signal. I send the PWM output to an LED and it blinks. So everything is correct for the design. For some reason sometime analog signal appeared in output of audio output and sometimes is absent.

[Payam]

I changed the power supply and now the second board I purchased works. The first board does not work. I think there is a hardware issue. Can anyone form digilent respond?

[JColvin]

Hi @Payam,

I apologize for the delay. Based on what you described the PWM audio output on the first Pynq Z1 is likely damaged, but I've attached a super simple .bit file that should play a tinny offkey G4 through the output (it'll be loud so don't put the headphones in your ear); you can load the bit file through the Vivado hardware manager or through the Digilent Adept software.

If it doesn't work on that first board, then it will be fairly conclusive that the audio output is damaged in some way and I can walk you through some next steps.

Thanks,
JColvin

top.bit

[Payam]

Hi,

I tried this using vivado. No output is obtained. The second board I purchased was working fine. However, today, the second board also does not produce any signal. Let me know what I can do?

Thanks

Payam

[JColvin]

Hi @Payam,

At this point, I would recommend that you reach out to whomever you purchased the Pynq Z1 and start going through the RMA process with them. In the case you purchased it from Digilent, you can fill out the Sales and Order Support form that is available on our website here: https://digilent.com/shop/shipping-returns/#return-policy; you can use this forum thread of evidence of having worked with an engineer regarding the fact that your board seems to have a manufacturing defect (or at least the IC is becoming damaged much earlier than it should and all it is receiving is a PWM input from the SoC that is within it's specification range).

Thanks,
JColvin