Zedboard connecting 7segment displayer

Hello,
I was wondering whether it is possible to connect a 4x7-segment led displayer to Zedboard for simple multiplexing purposes. If so please be so kind and explain a little bit of it, I'm totally new to Zedboard.

0 Former Member over 10 years ago

Sure, assuming you can physically connect your display to one or more of the five PMOD connectors on the ZedBoard or the FMC-LPC connector. You can take a look at the ZedBoard Hardware Users Guide for more details: http://zedboard.org/support/documentation/1521

If you are new to ZedBoard and the Zynq device you might want to spend some time going through the training materials available here:

http://zedboard.org/support/trainings-and-videos

In particular the Developing Zynq-7000 All Programmable SoC Software (Vivado 2013.3) and the
Developing Zynq-7000 All Programmable SoC Hardware (Vivado 2013.3) would be a good place to start.

-Gary
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0 Former Member over 10 years ago

OK I know how to connect it now, another question is, wont that amount of diodes turned on in the same time overheat Zynq?The circuit will be multiplexed, but still there will be like 8 diodes turned on at once (they are limited by 1k resistors), with 3,3V supply it gives around 2,6mA * 8, I have no idea how much this circuit can manage
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0 Former Member over 10 years ago

Let me be more specific, I got 2 of these
http://www.tandyonline.co.uk/media/wysiwyg/276-078-Two-Digit-7-Segment-Display-pins.png
So I have 4 digits and I want to use multiplexing, what I came up with is D1(a) D2(a) D3(a) D4(a) tied up together and same for other segments, it gives 8 bits required + 4 bits for common cathodes. The question is whether I can use JA1-JA10 + JB1-JB2 to be inputs for diodes in series with resistors and an output for common cathodes? To lower the current I can use bipolar transistors and control their bases, current for the base is then about 0,05mA. Is it a appropriate solution for connecting this led displayer?
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0 Former Member over 10 years ago

Conceptually what you describe should be OK. By my count, since JA-5 is ground and JA-6 is 3.3VDC, you will need to use two more signals on the JB connector. There are no electrical specification with the diagram you link to, so you will need to make sure that you do not exceed the voltage and current limits for the Zynq I/O configured as LVCMOS33 with your circuit. The Zynq 7020 data sheet is available here: http://www.xilinx.com/support/documentation/data_sheets/ds187-XC7Z010-XC7Z020-Data-Sheet.pdf

You will need to set your constraints to set the Zynq IO to LVCMOS33. And, since the PMOD IO are directly connected to the Zynq device, you will need to take normal precautions to prevent damage from static discharge or overvoltage conditions.

As a reference Digilent does make a PMOD 7-segment LED display module: http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,401,481&Prod=PMOD-SSD

-Gary
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