PYNQ: PYTHON PRODUCTIVITY

Pmod connect with Microblaze or ZYNQ?

Hi, Sir,

I want ask a question: if the PYNQ pmod module is based on Microblaze system, which mean I could not use ZYNQ system to connect Pmod IP, right? If I want use ZYNQ and python to control it, if I need write library about it by myself? Thank you!

Yes, you would need to write new code to control that PMOD device directly from the PS ARM processors. And then of course you would need to create the proper overlay to connect the PS directly to PMOD pins.

Hi, Schelleg,

Thank you! By the way, do you know the PYNQ PMOD module is based
on PMOD DA1 or DA4? Thank you!

Best regards,

The PMOD DAC driver is written for the DA4.

Hi, Schelleg,

I have bought Pmod DA4 and setup test system as PYNQ board recommeneded like following picture shown. But it doesn’t work (use PYNQ board base.bit and Pmod.DAC code, A pin has no response), Do you know why? Thank you!

I have seen the guide as below, Is this possible the internal clock problem? Thank you!

No, the docs you link to should not be the problem.

How are you testing it?
There is an example notebook here, but it includes a loopback test with an ADC:
https://github.com/Xilinx/PYNQ/blob/master/boards/Pynq-Z1/base/notebooks/pmod/pmod_dac_adc.ipynb
You can refer to the DAC part of the code.

If you are still having problems, please post your code and which version of PYNQ are you using.

Cathal

I just tested PYNQ/pmod_dac_adc.ipynb at master · Xilinx/PYNQ · GitHub and operating as expected. Let us know your setup. I tested on a PYNQ-Z2 with a v2.6 image.

1 Like

Hi,Schelleg and Cathalmccabe,

Thank you! I have found the problem. My setup sequence has problem. After run the code: dac = Pmod_DAC(ol.PMODB), I connect the Pmod_DA4 hardware module. after that, run the code: dac.write(2). It has no response. The correct way is connect the pmod_da4 hardware at first, then run all the code. The reason is the code: dac = Pmod_DAC(ol.PMODB) will initial the DAC chip and define reference voltage.
But I have another problem, if I want to use all 8 channels DAC output, If I need modify the library as below link said: Digilent PmodDA4
Thank you!

Hi,Schelleg and Cathalmccabe,

Thank you! I have found the problem. My setup sequence has problem. After run the code: dac = Pmod_DAC(ol.PMODB), I connect the Pmod_DA4 hardware module. after that, run the code: dac.write(2). It has no response. The correct way is connect the pmod_da4 hardware at first, then run all the code. The reason is the code: dac = Pmod_DAC(ol.PMODB) will initial the DAC chip and define reference voltage.
But I have another problem, if I want to use all 8 channels DAC output, If I need modify the library as below link said: Digilent PmodDA4
Thank you!