DSP-Crowd

Software for the Raspberry Pi to DE0 Nano connector

Used hardware

• DSP-Crowd's Raspberry Pi to DE0 Nano connector
• One of the following Raspberry Pis
  • Raspberry Pi Zero
  • Raspberry Pi Zero W
  • Raspberry Pi 1 Model A+
  • Raspberry Pi 1 Model B+
  • Raspberry Pi 2 Model B
  • Raspberry Pi 3 Model B
• DE0 Nano

Initial setup

The following steps must be done only once.

Note: This readme will be updated in the near future.

Power up the system

1. Connect an USB Micro B cable to the connector board. We recommend the official Raspberry Pi power supply as source
2. For the initial setup you also need to connect your DE0 Nano to the PC, because the initial design must be downloaded with Quartus
3. If you use a Raspberry Pi 1 Model B+ you also need to connect an USB Micro B cable to the Raspberry Pi while it is booting. After that you can remove this cable

On your Raspberry Pi

1. Copy the device tree overlay file _hello-world/raspberry_pi_zero/dts/overlays/dspc-de0_nano.dtbo from the repository to the directory /boot/overlays on your Raspberry Pi

pi@raspberrypi:~ $ sudo wget https://raw.githubusercontent.com/DSP-Crowd/software/master/_hello-world/raspberry_pi_zero/dts/overlays/dspc-de0_nano.dtbo -P /boot/overlays

2. Add the line dtoverlay=dspc-de0_nano in /boot/config.txt
3. Install the mtd-utils package with sudo apt-get install mtd-utils
4. Restart the Pi with reboot
5. After the reboot you should see a device called mtd0 in the directory /dev. Note: We assume a fresh Raspbian OS. If you already use another hardware extension it may not work as described here

pi@raspberrypi:~ $ ls -l /dev/mtd0
crw------- 1 root root 90, 0 Mar 29 23:17 /dev/mtd0

On your PC or Laptop

1. Download the initial design file _hello-world/de0_nano/output/rr_base.sof
2. Program the design file to your DE0 Nano board with Quartus. You can use the following command

quartus_pgm --mode=jtag -o p\;rr_base.sof

On your Raspberry Pi

1. Program the flash on the DE0 Nano board. See "Programming the DE0 Nano after the initial setup"

Final step

1. After that you can remove the cable on the DE0 Nano. You will never need it again

Programming the DE0 Nano after the initial setup

In this section, everything is done on the Raspberry Pi

1. Download the hello world designs for the FPGA:
   1. wget https://raw.githubusercontent.com/DSP-Crowd/software/master/_hello-world/de0_nano/output/rr_base.bin .. Slow blinking hello world led
   2. wget https://raw.githubusercontent.com/DSP-Crowd/software/master/_hello-world/de0_nano/output/rr_base-fast.bin .. Fast blinking hello world led
2. Clear the flash device, which is on the DE0 Nano FPGA board

pi@raspberrypi:~ $ sudo flash_erase /dev/mtd0 0 6
Erasing 64 Kibyte @ 50000 -- 100 % complete

3. Program the flash device

pi@raspberrypi:~ $ sudo dd if=rr_base.bin of=/dev/mtd0
411+1 records in
411+1 records out
210480 bytes (210 kB) copied, 0.973143 s, 216 kB/s

4. Check if the flash device contains your file from the Raspberry Pi. If you see EOF (which means End Of File), then everything is fine! :)

pi@raspberrypi:~ $ sudo cmp rr_base.bin /dev/mtd0
cmp: EOF on rr_base.bin

5. If something went wrong it looks like this:

pi@raspberrypi:~ $ sudo cmp rr_base.bin /dev/mtd0
rr_base.bin /dev/mtd0 differ: byte 33, line 1

Restart the FPGA on the DE0 Nano

Execute the following commands on your Pi:

1. Tell Linux that you want to use pin 18. This pin is used to restart the FPGA

pi@raspberrypi:~ $ echo 18 > /sys/class/gpio/export

2. Tell Linux that this pin is used as output

pi@raspberrypi:~ $ echo out > /sys/class/gpio/gpio18/direction

3. Finally set and then clear pin 18. Setting the pin will initiate the FPGA reconfiguration process

pi@raspberrypi:~ $ echo 1 > /sys/class/gpio/gpio18/value
pi@raspberrypi:~ $ echo 0 > /sys/class/gpio/gpio18/value

Use our helper scripts

This can also be done more convenient with our helper scripts

1. Download the scripts

pi@raspberrypi:~ $ wget https://raw.githubusercontent.com/DSP-Crowd/software/master/_hello-world/raspberry_pi_zero/scripts/fpga-reconf.sh
pi@raspberrypi:~ $ wget https://raw.githubusercontent.com/DSP-Crowd/software/master/_hello-world/raspberry_pi_zero/scripts/update-fpga.sh

2. Make our scripts executable

pi@raspberrypi:~ $ chmod +x update-fpga.sh fpga-reconf.sh

3. Run the script update-fpga.sh [file]. The parameter "file" is optional. The default is rr_base.bin

pi@raspberrypi:~ $ sudo ./update-fpga.sh rr_base-fast.bin
Erasing 64 Kibyte @ 50000 -- 100 % complete
411+1 records in
411+1 records out
210480 bytes (210 kB) copied, 0.966251 s, 218 kB/s
cmp: EOF on rr_base.bin