A few years ago I picked up a K55 dash-mount radar unit at a local hamfest. It's a fun device for a host of reasons. The remote that came with this system got me thinking early on about the possibility of capturing the speed data somehow. Fast-forward a few years and now I think I can pull this off with some help from other members of Bloominglabs. Now I live on a road where cars and motorcycles seem to love to race up my road. There are also dozens of car wrecks on the steep hill immediately past my house; according to public records my road is the most dangerous in the county. While talking to one of my neighbors he mentioned he had requested a radar speed-sign from the city but got blown off. I found myself thinking I could build one using my radar. I do find these signs somewhat annoying, but being a little older now I appreciate what they try to do.
I have two ideas in mind for this project. First, I'd just like to silently log speed data of vehicles on my road. After that, I would be interested in adding a large-format display of some kind.
Research and Preliminary look inside
Doing some googling I found one guy who had managed to read out speed data from an early model of this same unit with an AVR chip and send out RS-232 data. When we opened up my unit we found similar IC's inside as described by the previous link. Apparently the unit sends out BCD data to seven-segment display drivers so binary data can be siphoned off the board.
While I'm fine with adding a board to the main unit, I'd rather tap into the remote. If I could just make a module which plugs into the remote port and adds USB/serial out I would be very happy.
Build & Code
The remote control port appears to be a 24 pin Centronics connector (male). Places you can order this part:
More to come.