ZYBO Getting Started Tut UART Ouput Is Junk

[swimteam]

I have the ZYBO board. Using Vivado 2016.4 and SDK. I have followed the tutorial. The LED's work when the switch is on. The UART only shows garbage. I have tried the SDK Terminal, SDK Console, and Tera Term. All set up as stated. 

Anyone know what's wrong?

 

Thanks,

Swimteam

[D@n]

@swimteam,

If the UART is showing garbage, that's usually a sign that you have the wrong baud rate.

Dan

[swimteam]

There's nothing wrong with the baud rate. It's all automatic anyway. Beside I did an experiment. I pushed the PS button and the SDK Terminal showed the messages that were output. Only when it was done the that junk started to appear. That's positive proof the terminals are set up correctly.

[Piasa]

My hypothesis is that the interface is reconfigured at some point during the startup process.  Perhaps the rate or parity.

[swimteam]

That's an understatement. It took me two and one half days with 18 hours a day, reading the entire SDK manual, viewing Xilinx SDK YouTubes (actually worthless) to finally blink a silly led. I used a combination of two "easy" getting started ZYBO projects on the Internet. I just now have it working, blinking the 4 LED's. Now I have to find out why it works and get the UART to work.

For your info, one cannot use the Xilinx Web installer to download and install Vivado 2016.4 and SDK. At least it doesn't work on my ZBook 15. So, one has to find what they call an "image." This is a 20 GigaByte file that has all of the software. Everything. One has to download that and then run the setup that was downloaded with it.

Oh, I almost forgot.  It took 5 hours to download on my HP ZBook 15!

Thanks for taking the time to read my post.

Swimteam

 

[Notarobot]

Dear @swimteam

Your frustration is understandible but it's expected when one is starting learning such complex system as Xilinx Vivado. I spent a month to get myself comfortable with Vivado despite my prior experience with Xilinx ISE and FPGA development. There are a number of things you need to set up in Vivado to make it work, for example, IP libraries, board files, etc.

If you want help, please, describe what you are doing. People don't have time to guess or reproduce tutorials you are going through. Most of tutorials works if you follow prescribed procedures without shortcuts, for example, starting EDK outside of Vivado.

Regarding to the UART you can 1) check which UART is active in the Zynq processing system; typically stdin/stdout are using UART1; 2) check which UART is used in your C-code and instatiated in the xparameters.h; 3) check baud rates, typically stdin/out baud rate is 115200 but some tutorial indicate 9600.

In my experience garbage over RS232 was always because of mismatch of baud rates as D@n suggested. Sometimes things get to normal when I delete .sdk folder located inside the project folder. Restarting EDK recreates the .sdk folder with all necessary files and everything works.

Good luck!