Design of OpenVLC
The new OpenVLC1.3 takes advantage of the programmable real time units (PRU) included in the BBB. This,and the new receiver design allow us to increase the transmission frequency to 1 MHz and, thus, the communication rate. One cape can work as Transmitter (TX) or Receiver (RX).
If you have doubts and questions about these instructions, please leave your message in our Google group: https://groups.google.com/forum/#!forum/openvlc
Once it’s plugged, connect the 5 V power supply and that’s all.
ATTENTION: Be careful not to bend the components that stand out when you press or pull the cape.
Setting up the TX/RX
There are two parts in the TX/RX, the kernel driver and the PRU code. Follow these steps:
sudo mkdir bin
sudo ln -s /usr/bin/clpru clpru
sudo ln -s /usr/bin/lnkpru lnkpru
Working with the TX/RX
Once you have done the steps above in TX and RX, you can start using VLC as a common network interface.
You could measure the achievable throughput by using the iperf tool. To this end, launch iperf in client mode at the TX (sudo iperf -c 192.168.0.2 -u -b 400k -l 800 -p 10001 -t 100) and in server mode at the RX (sudo iperf -u -l 800 -s -i3 -B 192.168.0.2 -p 10001). Make sure that TX and RX have different IPs and the IP of the RX (iperf server) is 192.168.0.2.
The image below shows the results of an iperf test at 2.5 meters of distance:
Code and schematics are available at https://github.com/openvlc/openvlc
We don't plan to produce and distribute ourselves the boards in the near future, but if you are interested to produce them for the community at an affordable price, please contact us at firstname.lastname@example.org
The software solution is implemented as a Linux driver that can communicate directly with the cape and the Linux networking stack. In OpenVLC, the VLC interface is set up as a new communication interface that can take advantage of the vast range of Linux tools.
Creating the SD Card
We need to flash the BBB with a Debian image. To do that we need a SD Card with at least 4 GB. Follow these steps:
Flashing the BBB
Now that we have the SD Card ready with the image, we need to flash the BBB. Follow these steps:
Setting up the OS
The firsts steps are to prepare the beaglebone. This must be done in the OpenVLC board operating as TX as well as in the OpenVLC board operating as RX. These are the steps:
Connecting the cape
Connecting the cape to the BBB is quite easy. You just need to plug the cape to the correct pins as shown in the image below: