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botmagic
01-25-2006, 05:00 PM
Hello everybody.

The stepper motors I am using are the ones that are available for old floppy drives(5 1/2 inch).
Could anyone guide me regarding acceleration and deceleration of stepper motors using 8051.
The micrcontroller is AT89C52.
The Compiler used is Keil C.
I need the above for building a micromouse.
thanks in advance.

sidhant
01-25-2006, 08:15 PM
Hi!,
As far as my experience goes with stepper motors, alter the step delay for seed control. if your step delay is a function of time, you get an accelerated motion.

Maybe, i could help more, if you can be more application specific.. as in what exactly u wanna achieve?

Rgds,
Sidhant

botmagic
01-26-2006, 04:12 AM
thanks for the prompt reply...

I want to accelerate the micromouse to a high speed and then when it detects an obstacle i want to reduce the speed.

sidhant
01-27-2006, 06:19 PM
hey,
okie dokie. So you want to cover the obstacle free area as fast as possible.
If i had to do this, i would find wat min delay (ie max speed), micromouse can handle without loosing traction, so that there isnt a situation where our motor starts rotating so fast that it "slips" on the surface.. If the distance between two obstacles is large enough, then you can gain more speed by lowering delay after the initial slip phase.
now start looking for avoidance. If the weght isnt much than inertia should not be a big prob, coz best way to reduce speed almost instantaneously is to de-exite motor, the mag flux will act as breakes. In case, intertia is such that it slips while braking, then you need to slow it gradually by increasing the delay rapidly. or other way is to reverse direction of motor (which i don reccomend, it usually makes heavy bots either slip or loose control).
Actually to find balance between running speed andbraking, you'll have to expeiment a bit. Once you find the corect values, your micromouse will have real cool acc. and deacc. :)
Cheers!

Rgds,
Sidhant