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View Full Version : Black Jaguar (MDL-BDC24) as a Servo-Style PWM speed controler


AFM
09-11-2012, 13:22
I´m trying to connect a Black Jaguar using its Servo PWM input to drive a 12V brushed DC motor, but it is not working, that means it isn't generating any signal on its output.

First of all I've tryed to calibrate its PWM input according the instructions on "Stellaris MDL-BDC24 Brushed DC Motor Control Module Getting Started Guide (Rev. B) - spmu131b.pdf":

1. connected the 12V brushed DC motor to terminals M+ and M-;

2. applied 12V on terminals V+ and V- (at this point the LED starts flashing orange slowly);

3. applied a PWM signal to Servo PWM input (terminals S through a 560 Ohms resistor and -) - PWM signal parameters [ square wave, 4,75V, 15kHz, duty cycle 80%];

4. pressed USER switch for at least 5 seconds (at this point the LED blinks fast twice in orange color and continues flashing orange slowly, and not red and green indicating "calibration mode");

5. hold PWM duty cycle for 2 seconds;

6. turned PWM duty cycle to 20% for 2 seconds;

7. LED keeps flashing orange slowly.

Motor didn't move at any moment.

I've tried this procedure with two new Black Jaguar modules, and the behaviour was the same for both.

In this case I would like to make sure if this PWM parameters are correct for MDL-BDC24 (Black Jaguar) Servo PWM input.

Are such modules already programmed to control a DC motor through Servo PWM input at the moment they are shipped, or do I have to develop my own control firmware and install on it?

I would be thankful for any help you could provide in this case.

regards

artdutra04
09-11-2012, 13:58
3. applied a PWM signal to Servo PWM input (terminals S through a 560 Ohms resistor and -) - PWM signal parameters [ square wave, 4,75V, 15kHz, duty cycle 80%];The Jaguar requires a Servo PWM input signal (http://en.wikipedia.org/wiki/Servo_control), which is the same standard used in all hobby R/C servos.

AFM
09-11-2012, 15:39
Hi Dutra!, Thanks for your reply!

I follow your suggestion and just applied a signal to Jaguar Servo PWM input with the following characteristics:
Pattern A
1. 50Hz (20ms period);
2. pulse width (high level) 1ms / 1.5ms / 2ms ;
Pattern B
3. 300Hz (3.3ms period);
4. pulse width (high level) 1ms / 1.5ms / 2ms ;

In both patterns the motor didn't move.

In this case I wonder what is the timetable of Servo PWM signal for speed control of Black Jaguar. Because I didn't find in any description of this signal's timing in Ti, or Luminary micro manual's.