7 Segment display with Zybo Zynq 7000

[etienne68]

I have a Zybo Zync 7000 development board and I was wondering if there is a 4-digit 7 segment display that I can add that I can use from the FPGA? I have a project where I need to program a clock into the FPGA and display the time.
Thanks!

[JColvin]

Hi @etienne68,

Realistically, any 4-digital seven segment display that works with 3.3V logic (such as ones that set into a breadboard) will work with the Zybo board, though Digilent also has a Pmod version of a 2 digit seven segment display: https://reference.digilentinc.com/reference/pmod/pmodssd/start.

Just note that any traditional implementation with regards to controlling the 4 digit seven-segment display(without using something like an external multiplexer) will require at least 11 I/O lines, 12 if you also want to use the 8th segment (the decimal point), which can get pretty messy in terms of wires.

Let me know if you have any questions.

Thanks,
JColvin

[etienne68]

@JColvin, thanks for your response!  Quick question: the Zybo Zync 7000 has 4 2x6 ports on the same side of the board. I see the Pmod 7 segment display you provided the link for has 12 total pinouts and I'm wondering if I can use two of them side by side with the Zypo's 4 ports?

[JColvin]

Hi @etienne68,

Yes, putting two Pmods side by side across 4 ports will work. Please note though that since the Pmod SSD only uses 6 pins on each of their headers, this will leave the one half of the Pmod host port on the Zybo board (this condition applies for the original, now retired, Zybo, the Zybo Z7-10, and the Zybo Z7-20) unused and fairly inaccessible. If you're not concerned about that, then that's fine, but I would personally use cables of some kind (here are some examples of such cables courtesy of the Digilent store, link1, link2) to attach the seven segment display to the Zybo.

Thanks,
JColvin

[etienne68]

Hi @JColvin,

Thanks for sending the link to those cables. I can't tell from the description or the picture (eyes aren't great) but do you know if the one cable that is the split (2 to 1): is that a 2 6-pins to 1 12-pin connection? If it is then I should be able to use a single Pmod port for a single 2-digit LED add-on if I'm not mistaken

 

[JColvin]

Hi @etienne68,

The cable set in link1 actually comes with two cables. One cable is a 2x6 (single 12 pin connection) to a 2x6 (single 12 pin connection. The other cable does split a 2x6 (single 12 pin connection) into two 1x6 connections.

So yes, that second cable that does the splitting will allow you to use a single Pmod port for a single 2-digit 7-seg Pmod. Or alternatively, two different 6-pin Pmods on a single Pmod port.

Let me know if you have any questions about this.

Thanks,
JColvin

[etienne68]

Hi @JColvin,

So I think that answers my questions. This cable set should give me what I need and I should be able to use 2 7-segment displays with 2 onboard Pmod

ports.

Thanks! you were extremely helpful!