Using/Powering the VHN2SP30

Support Motor controllers/drivers and motors
1

Hello,

I ordered a VHN2SP30 MDO3A motor driver and would like to use it in conjunction with an Arduino UNO board. The Arduino is being powered by my computer through a USB cord. My understanding is that the cord provides 5V to the board. I have connected the Arduino 5V pin to the +5IN pin on the VHN2SP30 and the Arduino GND to the GND on the right of the VHN2SP30 +5IN pin. For testing purposes, I connected a 9V battery to the VIN and GND pins on the VHN2SP30 designated for the motors and I connected a small DC motor to the A and B connections to the right of the VIN and GND pins.

Now for my very noob question. How do I know the VHN2SP30 is on? No LEDs are lit on the driver and of course when I run my Arduino code, the motor does nothing. I am still very new to this level of electronics and I would greatly appreciate some help. Is it possible that I may have burnt the VHN2SP30 somehow?

2

Hello.

It is possible to damage the board by making incorrect connections, but I think it is more likely that you are just not using it right. For example, a 9 V battery is generally a very bad choice for high-current applications like driving a motor: they have low capacities and cannot deliver much current without experiencing a sharp drop in voltage. I suggest you disconnect your motors and instead use the motor indicator LEDs for feedback. I also suggest you effectively remove your Arduino sketch from the picture by hard-wiring the driver for, say, full speed forward. You can do this by connecting the PWM and InA pins to 5 V and the InB pin to ground while using 9V for VIN and supplying 5 V to the +5V (in) pin. You can use your Arduino’s 5 V output for this; if you do, don’t forget to make sure your Arduino and the motor driver share a common ground. If this gets a response from the driver, this would point to a problem with your software. If this doesn’t get a response, the driver might be damaged, or you might have a wiring problem. Please let me know what happens.

- Ben

3

Thank you so much! I wired everything like you suggested and the red led turned on.

4

I’m glad you were able to get the driver to do something. Does it work with your Arduino sketch yet (once again, I recommend you do initial testing with motors disconnected)? If you have trouble with your sketch, feel free to post it and I can take a look.

- Ben

5

My sketch still is not working properly with the motor drive. We are building an autonomous robot that uses 3 proximity sensors to control the motors. Ive provided my sketch below. Just like before, no LEDs turn on on the motor drive once i wire it into the arduino and I dont think the outputs from the sensors are taking any effect. I have only coded for the two sensors that directly control the movement of the motors. The third sensor will act as an interrupt. Please someone help me!

i just need an arduino sketch that can take the analog signal from two proximity sensors that effects the pwm output to the motor drive

int PWM_1 = 3;  // Motor 1 Control
int IN1_A = 4;
int IN1_B = 7;

int PWM_2 = 11; // Motor 2 Control
int IN2_A = 12;
int IN2_B = 13;

const int SNS_1 = A0; // Sensors
const int SNS_2 = A1;
const int SNS_3 = A3;

int sensorValue = 0;
int outputValue = 0;
int sensorValue1 = 0;
int outputValue1 = 0;
int sensorValue2 = 0;
int outputValue2 = 0;


void setup()
{
  Serial.begin(9600);
  pinMode(PWM_1, OUTPUT);
  pinMode(IN1_A, OUTPUT);
  pinMode(IN1_B, OUTPUT);
  pinMode(PWM_2, OUTPUT);
  pinMode(IN2_A, OUTPUT);
  pinMode(IN2_B, OUTPUT);
  pinMode(SNS_1, INPUT);
  pinMode(SNS_2, INPUT);
  pinMode(SNS_3, INPUT);
}

void loop(){
  int sensorValue = analogRead(SNS_1);
  int sensorValue1 = analogRead(SNS_2);
  int sensorValue2 = analogRead(SNS_3);
  outputValue = map(sensorValue, 0, 1023, 0, 255);
  outputValue1 = map(sensorValue1, 0, 1023, 0, 255);
  outputValue2 = map(sensorValue2, 0, 1023, 0, 255);
  Serial.println(sensorValue, DEC);
  Serial.println(sensorValue1, DEC);
  Serial.println(sensorValue2, DEC);
  
 if(outputValue <= 160, outputValue1 >= 90){ //Make the robot go left if to close to right
   digitalWrite(IN1_A, LOW);
   digitalWrite(IN1_B, LOW);
   analogWrite(PWM_1, 0);
   digitalWrite(IN2_A, HIGH);
   digitalWrite(IN2_B, LOW);
   analogWrite(PWM_2, 255);
 }
 else if(outputValue >= 90, outputValue1 <= 160){ // Make the robot go right if to close to left
   digitalWrite(IN1_A, HIGH);
   digitalWrite(IN1_B, LOW);
   analogWrite(PWM_1, 255);
   digitalWrite(IN2_A, LOW);
   digitalWrite(IN2_B, LOW);
   analogWrite(PWM_2, 0);
 }
 else{
   digitalWrite(IN1_A, HIGH); // Make the Robot go forward
   digitalWrite(IN1_B, LOW);
   analogWrite(PWM_1, 255);
   digitalWrite(IN2_A, HIGH);
   digitalWrite(IN2_B, LOW);
   analogWrite(PWM_2, 255);
 }
 
   
  Serial.print("sensor = " );                       
  Serial.print(sensorValue);      
  Serial.print("\t output = ");      
  Serial.println(outputValue); 
  Serial.print("sensor = " );                       
  Serial.print(sensorValue1);      
  Serial.print("\t output = ");      
  Serial.println(outputValue1);   
  Serial.print("sensor = " );                       
  Serial.print(sensorValue2);      
  Serial.print("\t output = ");      
  Serial.println(outputValue2);
}
6

Hello.

Can you first write a program that basically does what you did when you manually wired it instead of complicating the program with sensor readings?

- Ryan

7

here is the simple code. When I use the code below the red led on one side of the VHN2SP30 barely illuminates. The first digitalWrite under the loop is where I would like to use the PWM. I used the command analogWrite(PWM1, 255) to simulate the digitalWrite(PWM1, HIGH). When I do this, the red led does not illuminate at all, therefore I’m assuming I am using the PWM function incorrectly but I cant’t figure out how to use it correctly.

When I hardwire like Ben suggested, the red led illuminates brightly and when a motor is connected, it spins quickly. Is it dim when I connect it to the arduino because I am only using a 9V battery? The practice motor I am using is one of those very small DC motors from hobby stores

// This code is to emulate the Pololu VHN2SP30 being hard wired
// PWM and INa connected to 5V, INb connected to ground
// 5V supplied to motor drive from Arduino UNO board, both share common ground.
// 9V battery plugged into VIN

int PWM1 = 3;  //Connect to PWM 1 of VHN2SP30
int IN1_A = 4; // Connect to INa
int IN1_B = 7; // Connect to INb

void setup(){
  pinMode(PWM1, OUTPUT);
  pinMode(IN1_A, OUTPUT);  //Make pins outputs
  pinMode(IN1_B, OUTPUT);
}

void loop(){
  digitalWrite(PWM1, HIGH); // Max output through PWM (as if connected to 5V) 0 = no output 
                          // 255 = max output. Would like to use analogWrite(PWM1, 255) instead
  digitalWrite(IN1_A, HIGH); // INa on (as if connected to 5V)
  digitalWrite(IN1_B, LOW); // INb off (as if grounded)
}
8

Are you describing LED behavior with a motor connected? If so, can you disconnect the motor and just use the indicator LEDs?

When you say you’re using a 9V battery, do you mean something like this. If so, you should switch to a better power source as 9V batteries are not good for high-current applications like driving motors.

- Ben

9

That’s without a motor connected. once the motor is connected the light no longer illuminates. I do understand that the 9V battery does not have a high amperage, but the motor that i am testing the coding with is just like the one at the link below.

pololu.com/catalog/product/1117

10

It seems like there’s a good chance you have a power problem, so I don’t think it makes much sense trying to debug this further until you get a better power source.

When you say that your motor is “just like” our product #1117, do you mean that it has the same specs or just that it looks the same. If it’s the latter, you should note that the form factor of a motor is not a good indication of its specs, and small motors can still draw a lot of current, especially when starting at full speed from rest. For example, this motor looks the same as the #1117 motor, but it has a stall current of around 6 A at 9 V (compared to around 1.2 A stall current at 9 V for the #1117 motor).

- Ben