stepper motor with 16f876a

[jay543_uk]

hi all
iv been working on a circuit to convert a inductive type sensor output to a 0v to 5v square wave form. Iv got this sorted now but now i wanna drive a bipolar stepper motor from a 16f876a pic.
My project is a car speedo that uses a abs sensor as a speed sensor which sends its signs to a 16f876a and then i am planning to drive a bipolar stepper motor to indircate a speed by positioning a needle over the speed.
Are bipolar stepper motors easy to use and can they hold a steady position with out jumping around.

havnt really planned any of the code yet but i am also very new at .asm code so if any one can help with any code for the whole project i would love to hear it.

the abs runs off a 32 tooth ring so there are 32 square outputs to one turn of the road wheel.

thanls for any help

 

[Nigel Goodwin]

I wous suggest a unipolar motor, they are far more common and simpler to drive - both circuit and software.

 

[jay543_uk]

how much harder is it to control bipolar compared to unipolar, the only reason i ask is because i have a load of old instrument clusters which have bipolar stepper motors fitted to them which i can remove or i will have to go out and buy a bipolar instead. trying to save money

 

[blueroomelectronics]

Unipolars are very easy to drive with the cheap ULN2803. Bipolar requires push/pull drivers.

 

[jay543_uk]

guess i will be using unipolar instead then, the motors that i have at the moment i have just guessed they are bipolar because they have 4 wires.

could they be any other stepper motor or am i right in saying they are bipolar

 

[Nigel Goodwin]

Sounds bipolar, get a battery and a couple of pieces of wire and check them.

 

[jay543_uk]

so how can i tell a bipolar from a unipolar, iv looked on ebay and there are some small stepper motors with 5 or 6 wires, dont say if they are unipolar or not

 

[Nigel Goodwin]

so how can i tell a bipolar from a unipolar, iv looked on ebay and there are some small stepper motors with 5 or 6 wires, dont say if they are unipolar or not

Unipolar will have 4 wires, and bipolar will have 5 or 6 (usually!).

 

[sashidharan]

hi,
is there any possibility for controllin cell usin at commands...... wat type of cell ........and if any one havin software for sony 618i (at commands)............ plz help me.... i have to send sms from one mobile to anothr without touchin the mobile usin..... at commands via usb cable>>>>>>>>>>>>>>>>>>>>

 

[Mike - K8LH]

Unipolar will have 4 wires, and bipolar will have 5 or 6 (usually!).

I think you got that backwards Nigel. Unipolar are usually 5 or 6 wires and Bipolar is 4 wires...

 

[Nigel Goodwin]

I think you got that backwards Nigel. Unipolar are usually 5 or 6 wires and Bipolar is 4 wires...

Oops! - yes, slight typo!.