Simple WaveShare OV5640 Design for the Nexys 4 DDR

Summary

Requirements:

• Vivado 2018.1
• Nexys 4 DDR Board
• Connections between the OV5640 module and the PMOD headers (pins assigned to JA and JB)
• Waveshare OV5640 (tested on versions A and C)

This design demonstrates how to capture images from the OV5640 camera and write them to the VGA output on the Nexys 4 DDR board. Images are captured in RGB888 format from the OV5640 and displayed using the Xilinx TFT Controller IP at 640x40 resolution.

The design implements a simple passthrough from the OV5640 camera outputs to the VGA output, with a detour through DDR memory. Only a single frame buffer is used to store the image data in memory.

Building the design:

1. Source the build_hw.tcl file in Vivado to build the bit stream.
2. Export the hardware and open SDK
3. Create a new C application and add the test.c file
4. Program the bitstream and run the software application

Notes:

• The Nexys 4 DDR only connects four bits per colour channel to the VGA output. Nonetheless, for image processing applications, it may be useful to have 8 bits per channel as in this design.
• The AXI TFT controller expecteds RGB pixels to be encoded as 32-bit words. However, they only look at six bits per colour channel.
• The PMOD Camera adapter should be connected to headers JA and JB on the Nexys 4 DDR board.

References

• AXI TFT Product Guide: https://www.xilinx.com/support/documentation/ip_documentation/axi_tft/v2_0/pg095-axi-tft.pdf
• AXI VDMA Product Guide: https://www.xilinx.com/support/documentation/ip_documentation/axi_vdma/v6_3/pg020_axi_vdma.pdf
• Waveshare Resources: https://www.waveshare.com/wiki/OV5640_Camera_Board_(C)
• Digilent Board files: https://github.com/Digilent/vivado-boards/