As some of you know, I've been working on retrofitting my Microwizard P2XL with an Arduino timer for serial communication as well as timing. As an adjunct to that project, I picked up an old Raspberry Pi B+ as well as a V2 PiCamera, and thought it would be cool to interface them with the Arduino timer to add an instant replay to the system:
The cool thing about this system is that it doesn't rely on another sensor to trigger the replay - it simply gets a signal from the arduino timer when the first car finishes, then pulls video from a continuous loop (about 7 seconds) to make sure that it gets the first car finishing as well as any finishes which occur up to a second later or so. It then takes the 90fps video and pulls it down to about 20fps to give a slow motion replay.
In the video, I don't have the PC hooked up to get the serial communication, demonstrating how this system could be used stand-alone with any arduino based timer by adding a couple lines of code and a couple of resistors (for a voltage splitter) to the shield board.
I've got a little work to do, as the camera isn't well focused at this distance, and I'm not sure it is the angle I really want. Additionally I think I'll have the replay play two or three times total. At some point if I feel ambitious, I may do some basic serial communication to overlay text with finish times on the monitor, but that's a task for after I get all the electronics in a box.
So, for those of you who do use instant replay, what do you find is the most effective camera angle?
- Site Admin
- Posts: 4751
- Joined: Fri Jun 20, 2003 12:46 am
- Location: Highlands Ranch, CO
Awana Grand Prix and Pinewood Derby racing - Where a child, an adult and a small block of wood combine for a lot of fun and memories.
I like the idea of that, but it makes it hard to see the finish clearly if you aren't a little above the finish line, which of course makes it hard to see the whole track (especially where the gate is in the way).gpraceman wrote:I like the view from the end of the track, looking up towards the start line. I like to see the whole drama of the race, not just the finish, as some cars get a fast start but then get passed in the flat.
But I also agree that the drama of the race is fun to see as well! So, now I'm thinking two cameras, one placed on top of the finish gate facing the starting gate to show the "drama" at full speed, and another elevated above the finish line to show the "exciting conclusion" in slow motion. Not sure if I'll get both of them automated or not, but it's worth a try!
Certainly - my code is in the description of this youtube demo:
Here is some video of it in action on an actual track:
Note to get clear video you do have to focus the camera for this distance and make sure the finish line is well lit. Indoors we had a lot of speed blur.