EquipoiseBob
New Member
Hi All
I would like to make a light gate timer for timing F1 in Schools CO2 rocket cars. In essence the cars are tethered rockets that are fired up a 24 meter track. A slow car takes about 2 seconds to cover the distance, but competitive cars (Formula 1 class) cover the distance in about 1.02 seconds. There is also a Bloodhound SSC class which is virtually unrestricted and these cars cover the distance in about 0.65 seconds. Clearly for car development it would be necessary to time the cars to an accuracy of 0.0001 second or better.
I would like to be able to position a number of light gates at intervals along the track so that we can measure the speed in different phases of the run (the thrust dies out after about 0.5 seconds so the cars are decelerating for most of the run)
My idea is an initial gate at the start line. When this is broken a signal is set high. Each subsequent gate would use this signal to initiate its timing period and stop timing the moment the car interrupts its light gate. In my simple-minded fashion I envisage each gate having an LCD display from which the time at that point could be read.
I suspect the pulsein command could be used, but as this only runs up to about 0.6 sec some provision for over runs needs to be made, does pulsein set a flag anywhere accessible from the PICAXE programming environment to record overflows?
Bob (RobotBuilder)
I would like to make a light gate timer for timing F1 in Schools CO2 rocket cars. In essence the cars are tethered rockets that are fired up a 24 meter track. A slow car takes about 2 seconds to cover the distance, but competitive cars (Formula 1 class) cover the distance in about 1.02 seconds. There is also a Bloodhound SSC class which is virtually unrestricted and these cars cover the distance in about 0.65 seconds. Clearly for car development it would be necessary to time the cars to an accuracy of 0.0001 second or better.
I would like to be able to position a number of light gates at intervals along the track so that we can measure the speed in different phases of the run (the thrust dies out after about 0.5 seconds so the cars are decelerating for most of the run)
My idea is an initial gate at the start line. When this is broken a signal is set high. Each subsequent gate would use this signal to initiate its timing period and stop timing the moment the car interrupts its light gate. In my simple-minded fashion I envisage each gate having an LCD display from which the time at that point could be read.
I suspect the pulsein command could be used, but as this only runs up to about 0.6 sec some provision for over runs needs to be made, does pulsein set a flag anywhere accessible from the PICAXE programming environment to record overflows?
Bob (RobotBuilder)