Problem making a Stepper Motor Move?

[jean28 0]

Good day guys,

 

I bought this stepper motor to play around:

 

http://www.amazon.com/gp/product/B00DUSYEWY/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1#productDetails

 

It includes the very useful ULN2003 test board, which I am using to interface the MSP430 with the motor. The MSP430 is working perfectly fine (the Pins that are turned on have 3.3V), but the motor doesn't turn around. I am thinking that the reason that it isn't working is because I am powering the test module with the 5V that my Raspberry Pi provides.

 

I think these motors need around 500mA to work. Is there a way for me to get those mA to make the motor work?

 

I have left a picture of what I am trying to do so you guys can see.

 

 

Thank you!

[grahamf72 169]

You don't appear to have a common ground between the LP and the 2003 board. Link the grounds between the two and it will probably come to life.

 

 

Sent from my iPhone using Tapatalk

[enl 227]

Second that it appears the common ground is missing.

 

The driver is suitable for 500mA. That motor phases probably don't take that much. Measure the DC resistance of a winding. Should be about 50ohms, for a per-phase current of 100mA. Will likely be lower than this, as the ULN1003 has some voltage drop across it.

 

Also note that the max step speed is about 100 steps/sec, and you can't just go there. Need to ramp up speed, and ramp down to avoid losing positioning when stopping.

[enl 227]

Another question on the thought you may have a common ground through the power supply connections, even if not directly from the LP board):

 

Are you driving the pins in the correct sequence? Start with one at a time at maybe 2 changes per sec. A, B, a, b (or A, B, A', B'... or 1A, 2A, 1B, 2B... However the phases are labeled for this motor) Only one on at a time. This should give slow rotation.