Path to Programmable - The final two lessons! SW labs 10 and 11

This blog will cover the final two lessons in the Speedway Series for Software on the MiniZed. We'll talk about the built-in libraries and go through using the PMOD headers.

About:

Through Avnet, Xilinx and Element14, a training program to learn about the Zynq 7000 platform which is System On Chip combining an FPGA with an ARM processor. This comes to the students as complete development board packed with goodies like a wireless chip from MuRata (BT/BTLE/WIFI), 8GB Flash memory, onboard RAM, USB to JTAG (JTAG programmable over USB), Arduino-style headers (3.3V compatible only), Microphone, Bi-Color LED, and two additional expansion ports.

See all blog posts for this training here.

Lab 10 - Xilinix libraries

We have used these a little and talked about them in previous lessons. Xilinx provides lots of libraries, starter code, and examples for various use cases. Some System libraries include:

- XILmfs - Xilinx Memory File System

- LWIP140 - Networking - TCP/IP

- XILFLASH - Parallel Flash Common Flash Interface (CFI)

-XILisf - Xilinx In-System Serial Flash

In the lab, we will save a system setting to Flash so it is non-volatile.

One difference in this project is that we create a new Board Support Package instead of using the existing as shown below. This is because we are adding a new library that isn't needed in any other BSPs that we already have available. Remember that everything in this workspace is still built on the same hardware file (HDL) from Vivado; we are just adding different support on top of that for our software application.

The new project and BSP build and we can see them in the Project Explorer:

We program the FPGA then launch the new app which we have imported from the sample code. PuTTY gives us a nice ASCII image to look at when the program runs:

We were then able to read and write the MAC address on the board using this command line interface. Interestingly, the text input is not exactly filtering and sets invalid octects to 00 and doesn't say anything. But as a demo program, this is fine.

That's it for Lab 10 - we have used a library in our project and can use it to read and write to Flash (non-volatile) memory!

Lab 11 - TE PMOD Temperature and Humidity sensor

This lab covers using an I2C sensor on our PMOD headers to read data from. In this case, the target device is a TE Temperature and Humidity sensor. This will be good practice for me as my project will be very similar in the need to read from I2C and do something with the values.

For starting, we are again reminded that we can view the .mss file of the board support package to reach the implemented libraries and their documentation.

We then create a blank application and import source files from the training directory.

A math library is added to the Build Settings. It is called (cryptically) "M". This allows the application to build properly.

We program the bitstream to the MiniZed, then launch the program. From the console window (PuTTY), we can see a new interface with prompts for each of the functions in this demo program. Since I don't have the actual PMOD sensor, I get appropriate "Transfer Error" messages for every request.

That concludes the test lessons! I'm reviewing the code for Lab 11 as noted since it applies directly to my project for this training.

- James