Cmod S7-25 XADC Demo

Introduction

This project demonstrates how to use the Cmod S7-25's analog input pins with a MicroBlaze soft-core processor. Ten times per second, the processor collects samples from the on-chip ADC and prints voltage readings from Analog input pins AIN_32 and AIN_33 out over the USB-UART bridge. Care should be taken not to exceed the 3.3V maximum of the analog input pins.

Using This Demo

Requirements:

• Cmod S7-20
• Vivado+SDK 2018.2 Installation
• Tera Term Installation or other serial terminal application
• Test circuit (not described in this document).
• MicroUSB Cable

Release Usage:

1. Download and extract the release ZIP archive.

2. Open the included XPR project in Vivado 2018.2 (<archive extracted location>/vivado_proj/Cmod-S7-25-XADC.xpr).

3. In the toolbar at the top of the Vivado window, select File -> Export -> Export Hardware.

4. Set "Export to" field to "" and check "Include bitstream" box then click "OK".

5. In the toolbar at the top of the Vivado window, select File -> Launch SDK.

6. Set "Exported location" and "Workspace" fields to "" then click "OK".

7. With SDK opened, wait for the hardware platform to be imported.

8. In the toolbar at the top of the SDK window, select File -> New -> Application Project.

9. Fill out fields as in the table below. Most of the listed values will be the defaults, but are placed in the table for completeness.

Setting	Value
Project name	Cmod-S7-25-XADC
Use default location	checked box
OS Platform	standalone
Target Hardware: Hardware Platform	design_1_wrapper_hw_platform_0
Target Hardware: Processor	microblaze_0
Target Software: Language	C
Target Software: Board Support Package	Create New (Cmod-S7-25-XADC_bsp)

10. Click "Next", then select "Empty Application" from the list of available templates. Then click "Finish".
11. Expand the new application project (named "Cmod-S7-25-XADC") in the Project Explorer pane to the left of the SDK window.
12. Right click on the "src" subdirectory of the application project and select Import
13. In the "Select an import wizard" pane of the Import wizard, expand "General" and select "File System". Then click Next.
14. Fill out fields on the "File system" screen as in the table below. Most of the listed values will be the defaults, but are placed in the table for completeness.

Setting	Value
From directory	<archive extracted location>/sdk_appsrc
Files to import pane: sdk_appsrc	checked box
Into folder	Cmod-S7-25-XADC/src
Options: Overwrite existing resources without warning	checked box
Options: Create top-level folder	unchecked box

15. Click Finish.

18. Plug in a test circuit to the Cmod S7-25's analog input pins.
19. Open a serial terminal application (such as TeraTerm FIXME LINK) and connect it to the Cmod S7's serial port, using a baud rate of 9600.
20. In the toolbar at the top of the SDK window, select Xilinx -> Program FPGA. Leave all fields as their defaults and click "Program".
21. Right click on the "Cmod-S7-25-XADC" application project in the Project Explorer pane, and select "Run As -> Launch on Hardware (System Debugger)".
22. Refer to the statements printed via the serial terminal application for instructions on how to use the demo.

For more information on how this project is version controlled refer to the Digilent Vivado Scripts Repository