L298 and unipolar motor

Hi guys,

I've buyed from seedstudio the L298 Dual H-Bridge Motor Driver ( http://www.seeedstudio.com/depot/l298-dual-hbridge-motor-driver-p-284.html ) that should capable to drive two dc motor or one bipolar stepper motor.

Actually I've have just a spare unipolar stepper motor with 6 wires ( KH56KM2-016 ), I've read somewhere that it should be possible to wire a unipolar 6 wire in bipolar configuration but I can't find more info, also the documentation on the L298 driver don't tell much about how to interface stepper motor ( http://www.seeedstudio.com/depot/datasheet/L298%20Dual%20H-Bridge%20Motor%20Driver%20datasheet.pdf )

Anyone can give me some guidance? All should be drived by a seeduino (arduino clone) ...


try the scheme reported here... should work!


Thanks for the link lucareds7, looking the schematic the center connections of the coils are keeped unconnected :)

What is still not clear to me is how to wire the Motor Driver, actually I'm using the code in the bottom of that ( very well written!) article http://www.tigoe.net/pcomp/code/circuits/motors/stepper-motors with a 4-wire circuit configuration and the outuput pin 8,9,10,11 of arduino are connected respectively to I1, I2, I3, I4 input of the motor driver but the motor don't make any movement.

On the motor driver board there are also EA and EB input, the documentation say only "EA is connecting with PWM port of control board to control the speed of motor" but is only for DC motor or i still need to provide a pwm signal also for the stepper?

Here there is a photo of the hardware, it should be more easy to understand the connections

Still stuck with that driver, can someone give me a little help? :blush:

I also have a l298n I'm trying to get working. I however have a 4 wire stepper motor (bipolar). Referencing the datasheet http://www.st.com/stonline/books/pdf/docs/1773.pdf and referring to the figure labeled "block diagram" I figured out that the enable a and enable b pins need to be tied to logic high. Also referring to application information section 1.2 "a low state on the En input inhibits the bridge".

I had the problem of not realizing that pins 1 and 15 had to be grounded. The datasheet speaks of a sense resistor between these two pins and ground and the fact that the sense resistor controls the load current. My step motors current is well within the capacity of the l298n and my power supply so I grounded these pins.

I then wrote a program to turn pins 8,9,10,11 on and then off then the next etc.

Like this:

1 2 3 4 x o o o o x o o o o x o o o o x

stepper.h turns the pins on and off like this (from stepper.h source comments section)

Step C0 C1 C2 C3 1 1 0 1 0 2 0 1 1 0 3 0 1 0 1 4 1 0 0 1

and for me that results in less torque and jerkier motion..... im posting a new thread asking about the solution for this


nm just swapped output pins on the arduino now it runs smoother and stonger than ever....


Hi Robert, Thanks and sorry for late reply I was off home for a couple of days, in that weekend I'll give a good look to the l298 datasheet and try to understand how is wired the seeed driver. ( though I buyed that driver basically to not have any hassle with circuit testing... :~ ) )