DRP I/O ports connection in XADC and ZYNQ 7000

[Himanshu]

I am using XADC of Zybo board in DRP mode. I have connected the inputs of the XADC to a potentiometer supplying a voltage in between 0-1 V. I have used the PMOD pins to supply the output to external LEDs. But everytime the  board is programmed, the LED outputs show a garbage value which is constant. Changing the potentiometer voltage does not change the outputs. Also resetting the XADC through GPIO buttons has no effect. 

 

Please help with the above issue.

[jpeyron]

Hi @Himanshu,

I would suggest to look at the attached sdk code which was made for the Zybo. This should be a good reference for your project.

thank you,

Jon

zybo_xadc_test (7).c

[JColvin]

Hi @Himanshu,

How are you setting up the board? Are you following the Zybo XADC demo that we have available here?

Thanks,
JColvin

[Himanshu]

Actually I want to pass a sinusoidal signal through Vp-Vn pins of the XADC and take the output continuously on external LEDs through pmod pins.

Here is my design. Please check if this is correct.

Also guide me how to get a sampling rate of 1 ksps on the XADC as the lowest conversion rate possible is 39 ksps. I am providing a convst signal of 1 kHz , will that sample at 1 ksps?

[jpeyron]

Hi @Himanshu,

I believe my post on your other thread here should help you with this issue.

thank you,

Jon

[Himanshu]

Hi @jpeyron

Thank you for the helpful reply.

But my aim is to give a sine wave to XADC analog input and take its output continuously for 10 cycles. I am using vaux[14] pins ( which are connected to N15 and N16 package pins) for this purpose. But I am getting a garbage value in my output.

Please tell me how to apply the signal and what changes I have to make in XADC configuration.

As shown in the Lab3 design the vaux[0] and vaux[8] pins have been used to take input. My problem is that how to get these ports on the FPGA input-output ports as I have to apply a real time signal to it.

Thanks.