Arty XADC external voltage input

[Nystflame]

Hello,

I am using the microblaze system with the xadc on an Arty board.  I'm able to successfully read the internal voltages and temperatures of the chip, and I made some external pins (such as the VP/VN and Vauxp0 and Vauxn0). The pins which are external have been connected in a constraints file. My power supply positive terminal is hooked into the A0 port on my arty board, and the negative terminal is hooked into a gnd port. The XADC is attached to the AXI lite bus, controlled by the microblaze. Please let me know if any of this is unclear.

 

P.S. I've looked into the spec sheets but am still a beginner so I'm not always successful finding the right information.

 

Greatly appreciate the help!
Nystflame

[jpeyron]

Hi @Nystflame,

I follow the getting started with microblaze tutorial here with a couple of changes. After step 3.7 I edit the MIG and on step 5 I also add the xadc wizard, configure it , make the vaux 0,4,5,6,7,15,vp/vn external pins and connect the device out on the mig to the xadc for temp. I next make a wrapper and add the xdc file I have provided. I am able to get the VP/VN correctly working and I am getting voltage reading out of A0-A5. You only put the positive in A0-A5 with the negative already ran to ground I included a screen shot of the schematic show this. The VP/VN is the only one that I made that needs a p and n connected. I have attached a screen shot of my block design, the xadc wizard settings and disabling the xadc in the MIG. I have also included my xdc and my sdk code. In sdk use the hello world application and copy paste the code i have provided into the hello world. My vn/vp reading are right one but A0-A5 voltage reading are not correct. I am still working on the A0-A5 issue but might not be done right away.

cheer,

Jon

arty_xadc_xdc.txt

arty_xadc_sdk.txt

[Nystflame]

@jpeyron

Thank you very much for all of his help! It's working great now for me after following what you had done. The voltage readings were off on the A0-A5 inputs because the function in the code you provided for calculating the raw to voltage is using 1.0V instead of 3.3V as the circuit suggests in the schematic you provided above.