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Has anyone tried using a parallax or picaxe chip to count revolutions for their vehicle? I run into the same problem in both languages and neither manufacturer is able or willing to help me. I don't want to resort to timing for the states since in my testing, that was always the least accurate, and our school doesn't want to pay for a VEX chip which would end up costing >$300 after all the other components. I guess i could settle for a mechanical stop.

I could see a few reasons why a Parallax BASIC Stamp or PICAXE would not be ideal for EV, but what's the problem you're having?

Ok, now its easy for me to line my car up when there are tiles to line it up but what is the best way to line you car up if you only got the tape on the track?

I used a scope.

gh wrote:I could see a few reasons why a Parallax BASIC Stamp or PICAXE would not be ideal for EV, but what's the problem you're having?

I tried using mechanical switches and hall-effect sensors, but when i get to the point of the code where it is supposed to start counting how many times the switch was toggled it either immediately stops in Propeller or restarts in PICAXE. Are there any other manufacturers you would recommend? I got started with programming towards the end of last year when a senior (who is no longer with us) pretty much just handed me Propeller Demo Board and a link to the manual and told me to do it. Any websites where I can read up on this stuff?

sirup96 wrote:Ok, now its easy for me to line my car up when there are tiles to line it up but what is the best way to line you car up if you only got the tape on the track?

It's a good idea to have a target at the end and have some sort of sight/scope on your car. Last year I used two pieces of plastic (one on the front and one in the back) with holes in them. I would look through the hole of the one on the back of the car, through the hole in the piece on the front, and at a line drawn on my target at the end of the track. My car never went perfectly straight so I couldn't line everything up dead center, but I know how much I had be off while aligning it to know it would still end up right on the mark when it stopped. This is where lots and lots of practice comes in.

I grabbed the viewfinder off my telescope and attached it to the top of the vehicle. Then I adjusted it so the crosshairs zeroed in on where it would stop. Didn't get it perfect, but it certainly would have been possible.

ahage16 wrote:I tried using mechanical switches and hall-effect sensors, but when i get to the point of the code where it is supposed to start counting how many times the switch was toggled it either immediately stops in Propeller or restarts in PICAXE.

Well, since this sounds like a software error, I don't think replacing it with another system would solve the problem. The question is, what are you doing to count the switch toggling? Are you going into a loop to continuously check for changes in the state of the switch? Is there a condition for breaking out of the loop to do processing or output?

My aiming device is in the Image Gallery. I'd like to go back to a scope though.

gh wrote:

ahage16 wrote:I tried using mechanical switches and hall-effect sensors, but when i get to the point of the code where it is supposed to start counting how many times the switch was toggled it either immediately stops in Propeller or restarts in PICAXE.

Well, since this sounds like a software error, I don't think replacing it with another system would solve the problem. The question is, what are you doing to count the switch toggling? Are you going into a loop to continuously check for changes in the state of the switch? Is there a condition for breaking out of the loop to do processing or output?

My aiming device is in the Image Gallery. I'd like to go back to a scope though.

In propeller I tried having a loop that added one to a variable every time an input was toggled and the it would exit the loop when the variable is equal to whatever it needs to be for that distance. I also tried making a loop that would repeat once the switch was toggled and put the variable in the number of loops, but both exited the loop after the switch was toggled one time. If you know propeller or PICAXE, I could just post the code.

Are there any brand of microcontrollers someone could reccomend for this application

Did you debounce the switch closures? This can be done with either software or hardware.