BS2 & DS3658 High Current Stepper Driver

Fdawg

PLEASE VIEW THE FOLLOWING MS WORD DOCUMENT DESCRIBING MY PROBLEM

I NEED HELP WIRING UP THE BS2PX AND THE DS3658 HIGH CURRENT DRIVER - I AM USING THE EXAMPLE FROM STAMP WORKS (V2.1) EXPERIMENT 27: STEPPER MOTOR CONTROL.

ALL I AM DOING IS SWAPPING THE DRIVER CHIP AND AM UNABLE TO GET IT TO WORK.

THANK YOU SO MUCH!

fdawg

Mike Green

The L293 and the DS3658 are completely different parts. They have completely different connections although they're functionally similar. You have to download their respective datasheets and compare the connections, then figure out how the DS3658 needs to be connected to work the same. The two parts do have drivers with protection diodes. They do have logic inputs, but the enable lines are wired differently and, as mentioned, the pinouts are completely different.

Fdawg

Hey thanks for your timely response Mike!

Sure thing - i understand - in one configuration (one chip) i'm sourcing current and sinking in the other.

i have the data sheets and followed their application schematics.....

it almost leads me to believe i might have a bunk batch of driver chips - i do have more coming in today....i mean - even if the leads are reversed, the stepper should still be energized - i just cant get it to energize....

i discussed this issue with some folks at work who have some stepper experience and tried a couple different ways...

i attached a microsoft word document to my initial post below (ds3658&stamp_final.doc) - it details how i wired it up and about the code, components, etc...

thanks again - i'll keep updating my efforts

Mike Green

Pin 14 of the DS3658 is an enable pin. You have it connected to ground which will turn off all the output drivers. Try connecting it to +5V or to another Stamp I/O pin which is set to HIGH.

Fdawg

Hey - i just tried that - i was able to get a little motion from the motor - seems like the step sequence is off...

Also, the driver got super hot.

I wondre if i should be toggle the enable as i drive each step in order to reduce heat?

Also, the stepper is energized, but i am easily able to overcome and turn the shaft by hand - it doesn't seemed energized entirely...

and - i just lost power to the boe(need to take a multimeter to it and figure out what the heck happened) - i have a couple spares tho....

Fdawg

OK - so in my haste I accidentally tied Vdd into the ground on the DS3658 - which is tying Vdd to Vss and i smoked (visibly smokeless but i bet it sure felt it) my 2px....

i grabbed another 2px off another project and am back to business....

Mike Green

When you're sloshing any kind of power around ... more than a few milliwatts, you need to understand what you're doing first.
Go back to basics and decide (on paper!) what kind of pulses you want to produce to what windings in what order for how long, etc.
Make sure it makes sense, then look at your program to make sure that it will produce the signals needed for the driver.
Then look at how you've really hooked up the driver (not what you think it should be) and make sure it will do what you expect.
Then and only then should you apply power. You might want to run the enable line into the Stamp so the Stamp can turn on the
driver only when it's ready to step the stepper and turn it off otherwise. When the Stamp is reset, the enable output will be off
(if you use a pulldown resistor on it).

It gets expensive to have to replace parts because of catchable errors.