PYNQ-Z1 and PYNQ Shield combo

[Robert Craven]

Hi all,

    Can I use the PYNQ-Z1 and PYNQ Shield combo to drive 20 Mosfets (i.e. digital outputs).  I assume I can drive 14 based on the labelling of the ports, but I'm not familiar with wheter any of the other sockets can be driven as a Digital Out.  (or maybe I don't know anything, lol)  All my current FPGA work has been with National Instruments RIO boards and modules.  I am looking for another vehicle for my research and I need to drive 20 digital outputs.

 

thanks

 

MtneerInTN

 

[JColvin]

Hi @Robert Craven,

The Pynq Z1 with it's Arduino styled shield connector (more details in the Pynq Reference Manual here) can drive 20 MOSFETs (provided the MOSFETs have a Vgs at 3.3V) since as per the Xilinx Zynq 7020 DC and AC Switch Characteristics datasheet, each pin can provide up to a maximum of 10 mA, with a total of 200 mA per bank. The IO on the shield connector are split between a couple of different banks so ideally you will not run into the current limit for each bank, though you will likely want to double check.

Let me know if you have any questions about this.

Thanks,
JColvin

[Robert Craven]

Thanks!

I will only have one digital output line on at a time (sequenced through quickly) so I think the power requirements will be easy to meet.  I see lines associated with sockets on the  PYNQ Shield marked d0-D13 for 14 output lines, but am not sure what other lines can be used for digital outputs to make up the 20?  I'm scared that some are dedicated to analog I/O?  If not, which ones can be used for digital outputs?  Thanks

[JColvin]

Hi @Robert Craven,

For the Pynq-Z1, you can also use IO26-IO41 as digital output (or input) pins; there is an image showing where these pins are located on the Pynq Z1 in it's Reference Manual here: https://reference.digilentinc.com/reference/programmable-logic/pynq-z1/reference-manual#arduinochipkit_shield_connector.

Let me know if you have any other questions about this.

Thanks,
JColvin