RESOLVED: 2.5 Amp Bipolar Stepper Controller

Forum 2005-2010 (read only) Hardware Interfacing
1

Looking to integrate the following micro-stepper controller with an arduino 328 / arduino mega:

Critical Velocity : 2.5 Amp Microstepping Bipolar Stepper Motor Driver from critical velocity

Should the input ST & DIR from the Arduino be isolated with a resistor to prevent kickback from the stepper coils?

Anyone have any ideas on how to wire this up as its not the std motorshield :frowning: I have 2 4 wire bipolar steppers that I would like to test as they have significantly difftorque output and Id rather use the smaller if possible.

thx

2

Controller: Critical Velocity - 2.5 Amp Microstepping Bipolar Stepper Motor Driver P/N: ST-1
Spec Sheet: http://www.criticalvelocity.com/products/datasheets/st1.pdf

3

Should be a pretty simple setup. The digital inputs to the controller, step and direction are optically isolated so no protection diodes will be needed. Just wire the step and direction signals to two Arduino digital output pins and wire the Arduino ground pin to the isoground shown on the very first connection drawing shown in the data manual. Also that very first wiring example shows a 4 wire stepper connection.

Good luck

Lefty

4

RetroLefty,

Thank for chiming in. I wired up the controller with a 12V 1.25A Ac Adapter, connected a M42sp-13NK (printer salvage) to the driver after reading the paired wires resistance at 4.7Ohms and finally to the arduino via pin 7 for DIR and pin 9 for STEP.

juiced everything and nada... nothing!

ARDUINO #9 -> Controller STEP
ARDUINO #7 -> Controller DIR
ARDUINO GND -> Controller ISOGND

Controller V+ <- 12V AC @ 1.2A Regulated PSU
Controller GND <- 12V AC GND
Controller 1A -> Stepper Red
Controller 1B -> Stepper Black
Controller 2A -> Stepper Blue
Controller 2B -> Stepper Yellow

5

Can you post your sketch program? Use the insert code button at the top of the posting window.

PS: you posted:

Controller V+ <- 12V AC @ 1.2A Regulated PSU

I hope your external power supply is 12 DC not AC ?

Lefty

6

Just changed it to pins 2 & 3 for a test using this code from LusoRobotica adding LED blinking to see when it should be firing.

int dirPin = 2;
int stepperPin = 3;
int ledPin = 13; 

void setup() {
  pinMode(dirPin, OUTPUT);
  pinMode(stepperPin, OUTPUT);
}

void step(boolean dir,int steps){
  pinMode(ledPin, OUTPUT);
  digitalWrite(dirPin,dir);
  delay(50);
  for(int i=0;i<steps;i++){
    digitalWrite(stepperPin, HIGH);
    delayMicroseconds(100);
    digitalWrite(stepperPin, LOW);
    delayMicroseconds(100);
  }
}

void loop(){
  step(true,1600);
    digitalWrite(ledPin, HIGH);  
  delay(500);
   digitalWrite(ledPin, LOW); 
  step(false,1600*5);
  delay(500);
}
7

Code looks OK. Did you see my PS in my last post?

Lefty

8

9

LOL Yes its a Delta AC/DC Regulated Adapter: AC 100-240V 0.50A @ 50-60Hz -> 12V 1.25A DC

10

Is there any holding force on the motor when it's all power up compared to when it's not powered up? I can't see any wrong with your hook up. Is there a motor voltage rating on the motor lable?

This would be the time I would break out the scope and meter and check for signals on the input and voltages and current values.

Lefty

11

There is also a current adjust pot somewhere on the controller.

"
Motor Current Adjustment:
Use the motor current potentiometer to adjust the current level to suit the motor. Do not exceed the
motor's current rating to prevent overheating. The full scale of the current adjust potentiometer is from
2.5A down to 0.25A at the rightmost position. "

Lefty

12

Tried that also.... left to right with and without motor attached did nothing

13

Working !!!

Ok I am a chimp.... after working a 14 hour day and coming home to do this project I read the PSU on the meter and reversed the polarity to the controller after I was done.... everything workds wonderfully and I now am going to facepalm myself LOL

Thanks for your help Lefty :slight_smile:

BTW controller works amazingly.... 1/8th step resolution is awesome!

14

Glad it worked out for you. Remember, we learn 100 times better from our mistakes then out successes.

Lefty