Recently, I helped a colleague to get a basic Visible Light Communications (VLC) experiment up and running. I was really surprised how straightforward that went.

We used two Ettus Research N210 with LFTX/LFRX daughterboards, an off-the-shelf photo diode and a custom LED driver that converts the output voltage to a corresponding current.

I tried my GNU Radio IEEE 802.15.4 transceiver and my car key fob transceiver. Both worked out of the box. To be honest, I’m not completely sure why O-QPSK worked – but hey, not my department :-)

Just to be clear, every time the LED switches on, it transmits a whole frame. For IEEE 802.15.4 that was a chip rate of 2Mcps with a data rate of 250kbps.

• reddit
• twitter
• facebook
• google+