I am about to start a project where I want to build a drag strip timer for model cars or robots. The project will be built for a 11 metre track which is 40cm wide.
I am going to use an Arduino Leonardo, probably use HC-SR04 ultrasonic sensors to trigger the recording of time at the start and finish. (1 sensor at start, 1 at finish)
Is the HC-SR04 suitable for this application or would I be better using Sharp digital IR sensors to trigger the recording of the start time and finish time of the race?
The result would be calculated and then displayed on an LED screen.
Vertically stack pair at end so that you minimize erroneous trigger error by say a bird for piece trash blowing around.
Horizontal stack 2 at beginning so you can stage correctly and put one set maybe 1/20 way down the track so you can measure initial acceleration..
Add a Epson style receipt printer to hand out the time slips..
orare76:
Is the HC-SR04 suitable for this application
No. An optical interruption sensor at the start and finish lines would be much more accurate. Don't you need a second sensor at the start to indicate that the car is lined up?
orare76:
or would I be better using Sharp digital IR sensors to trigger the recording of the start time and finish time of the race?
I don't think that one would be a good choice either. You want a solid transition the instant a tire crosses the line.
A real drag strip timer begins timing when the light goes green. The light beam sensor at the beginning detects a car starting before the green light.
Paul