Schematic on Arduino PWM Motor Controller & Driver

I am looking to hook up my Arduino Uno to a motor controller via motor driver. Motor controller to reduce speed and motor to change shaft direction. Does any know how the connections can be made?

I have read about transistor relays, but I am trying to avoid those at all cost since I have just bought the motor driver.

Btw, Its a Pololu 15 Amp high-power motor driver and a 50 A PWM Digital Motor Controller for a 24 V DC motor

Thank you

By now, I would think that you would know that the first thing that is going to be asked is for you to post links to the hardware you have.

Why do you want to use both the driver and the controller?! Based on the 350W motor - I'd go for the 50A controller. If it's the one I expect you've seen - I can give you a circuit to controller the speed from an arduino PWM pin.

Why do you want to use both the driver and the controller?!

If I can go without using both that is fine, but I will still need to control the speed and shaft rotation.

By now, I would think that you would know that the first thing that is going to be asked is for you to post links to the hardware you have.

Here are the links to the devices on sparkfun.com

http://www.sparkfun.com/commerce/product_info.php?products_id=9950

http://www.sparkfun.com/commerce/product_info.php?products_id=9668

http://www.sparkfun.com/commerce/product_info.php?products_id=9107

Thank you

The 50A controller is the one that I expected. I have something similar. I'm pretty sure that it doesn't have a reverse capability. Is this something that you need?

Is this something that you need?

Yes I need to lower the rpms while allow it to run in one direction for a few seconds and reverse direction for a few seconds and repeat?

Also is how do you connect the controller to the Arduino is it through the "SW?"

The arduino essentially replaces the potentiometer used to control the duty cycle and hence the speed. It can't do this directly but it's just a simple circuit. You'll also need something to reverse direction. It's a shame that your motor is so large. If it was smaller - I'd jump at the polulu item as it would be much easier to implement.

Below is the K243 h-bridge kit that might be of interest. Most of the large h-bridges with pots probably can be easily modified to use pwm from the arduino if desired.

http://secure.oatleyelectronics.com//product_info.php?cPath=94&products_id=206&osCsid=30093449b694ae247d94c2bcce5d0560

Thank you for the information, but I was looking for a way to use my motor driver and controller that I already have.

I hope this is possible, but if not, I will have to go that route.

I have just discovered that I will not be able to interface the two (or at least that I don't know how). I am now looking for other options. Since being able to change the direction of the shaft is more important, I have decided to just stick with the motor driver 15 A. But the RPMs are just too great. Is there a way to decrease the output voltage and hopefully that will slow down the rpms?

Thank you for your time.

Can I use a voltage regulator to step down the voltage from the output of the motor driver to limit the shaft rotation?

Thank you

It's a larger motor and I don't have enough time to order. But would a voltage regulator work?

Thank you

Can you explain why it wouldn't work so I can at least save the 2 dollars I would spend? I mean, it makes sense to reduce the incoming voltage to the motor would limit rotation.

Radio shack sells one for up to 37 Volts output

If this doesn't work. Do you have any other quick suggestions?

I thought I did earlier in the post. But its a 24 v 350 ? DC reversible motor.

Excuse the question mark. 350 watts. The motor will have a drive wheel to propel/slowly slide a steel bar. So not much torque can be sacrificed.

Just use the 50A controller and a double pole double throw relay (or a pair of SPDT) to switch direction. To preserve the relays implement a scheme that ensures that the motor controller speed is 0 before switching direction. With this in place - standard automotive relays can be used.

That is exactly what I ended up doing, but the two don't seem to work together. There doesn't seem to be enough output voltage after leaving the relays to go into the controller . Unless there is a different way to hook it up?

To preserve the relays implement a scheme that ensures that the motor controller speed is 0 before switching direction.

Can you explain what you mean by that?

A relay is completely passive and shouldn't limit current or anything else - please share you schematic.

The process for changing direction would be:

Request to change direction set motor speed to 0 change motor direction

The reason for this is that if you try to change direction with the motor speed set high, the current going through the relay may be sufficient to weld the contacts closed, during opening and close,or otherwise cause huge amounts of errosion to the contacts. If you've hooked your motor up to batteries to test, cast you mind back to the big sparks you got when you connected the wires. Been there done that learned the hard way.

My schematic is very similar to the link below.

http://www.commandocaralarms.com/info_spdt_relays.asp

87a and 85 to ground, 87 and 86 to 12 V, and 30 to the motor.

One of the 86 are connected to a FET then a 2.2 Kohm resistor then to the Arduino pin output. The other 86 of the other SPDT is connected to a different FET then to another 2.2 Kohm then to another pin output of the Arduino.

That way I can turn on direction on and off or turn them all off.

I do not think the motor speed controller (link below) is able to turn on/off with connection to the Arduino.

http://www.sparkfun.com/products/9668

Thank you