The project under consideration is a speed trap for R/C Model Warship combat.
The basic setup and function:
Setup: 2 lasers are set up, parallel to each other, close to the water (but above the waves) projecting across the speed trap, into 2 sensors, call them A and B. Most ships are longer than the trap, but some may be shorter, or so low to the water that only a piece of the superstructure interrupts the beam. The sensors are probably less than 1 ft apart.
As the ship goes through in each direction (say first is A to B), it interrupts the light beam at A, tripping the sensor, and then, a short time later, interrupts B. Going the other direction, of course, reverses this. It should be able to handle entry from either direction at any time (in other words, no directional preference or requirement - you may have several go AB in a row and then some come back and BA with others not).
The critical information is the interval between A and B each being initially tripped. Keep in mind that B may be tripped while A is still active (the beam still occluded), as ships range up to about 2 meters in length.
What I would like as the end result is to generate a stream of pulses that I can send to a bike computer as the readout - or, to put it in more functional terms,
Sent pulse stream that gives a result of, say, 10 MPH on the bike computer.
Once the interval is timed, change the pulse stream to an interval that the bike computer reads as the model speed based on our calculation (not a true scale), that will, in turn, bive a seadout in the 22-60 knot (or mph is fine) range for, say 10 seconds.
After 10 seconds, return to standby pulse stream of 10 MPHto indicate ready for next ship.
I am trying to wrap my mind around the easiest/best way to do this. A latching relay would probably work, and I could tweak around the delays. Or creatively programming a second Picaxe to act kind of like a flip-flop
(on A or B turn pin X high,
on the other turn pin X back low),
and read the pulse thus generated with a second Picaxe's Pulsin.
My electronics is a bit rudimentary, but are there some "simple to implement" solutions, either in hardware or software that I am overlooking?
Oh, almost forgot one of the parameters. The time it takes to transitin between sensors should be on the order of large fractions of a seconds (say 0.1 to 0.6 second).
Thanks in advance for any suggestions.
Wreno
Edited by - wrenow on 21/12/2006 18:44:08
The basic setup and function:
Setup: 2 lasers are set up, parallel to each other, close to the water (but above the waves) projecting across the speed trap, into 2 sensors, call them A and B. Most ships are longer than the trap, but some may be shorter, or so low to the water that only a piece of the superstructure interrupts the beam. The sensors are probably less than 1 ft apart.
As the ship goes through in each direction (say first is A to B), it interrupts the light beam at A, tripping the sensor, and then, a short time later, interrupts B. Going the other direction, of course, reverses this. It should be able to handle entry from either direction at any time (in other words, no directional preference or requirement - you may have several go AB in a row and then some come back and BA with others not).
The critical information is the interval between A and B each being initially tripped. Keep in mind that B may be tripped while A is still active (the beam still occluded), as ships range up to about 2 meters in length.
What I would like as the end result is to generate a stream of pulses that I can send to a bike computer as the readout - or, to put it in more functional terms,
Sent pulse stream that gives a result of, say, 10 MPH on the bike computer.
Once the interval is timed, change the pulse stream to an interval that the bike computer reads as the model speed based on our calculation (not a true scale), that will, in turn, bive a seadout in the 22-60 knot (or mph is fine) range for, say 10 seconds.
After 10 seconds, return to standby pulse stream of 10 MPHto indicate ready for next ship.
I am trying to wrap my mind around the easiest/best way to do this. A latching relay would probably work, and I could tweak around the delays. Or creatively programming a second Picaxe to act kind of like a flip-flop
(on A or B turn pin X high,
on the other turn pin X back low),
and read the pulse thus generated with a second Picaxe's Pulsin.
My electronics is a bit rudimentary, but are there some "simple to implement" solutions, either in hardware or software that I am overlooking?
Oh, almost forgot one of the parameters. The time it takes to transitin between sensors should be on the order of large fractions of a seconds (say 0.1 to 0.6 second).
Thanks in advance for any suggestions.
Wreno
Edited by - wrenow on 21/12/2006 18:44:08