Motorboard LED function: Blinks only with forward/backward

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macaqa
 
Posts: 2
Joined: Mon Dec 27, 2010 2:16 pm

Motorboard LED function: Blinks only with forward/backward

Post by macaqa »

Hi,

I recently assembled the adafruit motorshield and connected it to arduino. Default state of LED on motorshield is off (e.g. with Blink.pde). On uploading motortest.pde to arduino, the LED blinks for the motor is set to run and switches off for the duration of release. I confirmed this with the serial monitor reading which matches LED on/off. This also aligns with voltage read through a multimeter ( Voltage reversal aligned with LEDs/TickTackTock on serial monitor.Unfortunately, I can not test the output with motors because I have 1.5V motor only,

However, from the FAQs state" The Stepper and DC motor connections wont do a single thing if the LED is not lit".

Am I doing something wrong? Any pointers would be much appreciated.

Thanks!
Maq

Code: Select all

// Adafruit Motor shield library
// copyright Adafruit Industries LLC, 2009
// this code is public domain, enjoy!

#include <AFMotor.h>

AF_DCMotor motor(4);

void setup() {
  Serial.begin(9600);           // set up Serial library at 9600 bps
  Serial.println("Motor test!");

  // turn on motor
  motor.setSpeed(200);
 
  motor.run(RELEASE);
}

void loop() {
  uint8_t i;
  
  Serial.print("tick");
  
  motor.run(FORWARD);
  for (i=0; i<255; i++) {
    motor.setSpeed(i);  
    delay(10);
 }
 
  for (i=255; i!=0; i--) {
    motor.setSpeed(i);  
    delay(10);
 }
  
  Serial.print("tock");

  motor.run(BACKWARD);
  for (i=0; i<255; i++) {
    motor.setSpeed(i);  
    delay(10);
 }
 
  for (i=255; i!=0; i--) {
    motor.setSpeed(i);  
    delay(10);
 }
  

  Serial.print("tech");
  motor.run(RELEASE);
  delay(1000);
}

User avatar
adafruit_support_bill
 
Posts: 88142
Joined: Sat Feb 07, 2009 10:11 am

Re: Motorboard LED function: Blinks only with forward/backward

Post by adafruit_support_bill »

The LED indicates power to the H-bridges.
How are you powering you motors? Via the Arduino supply or with an external supply? Is the EXT_PWR jumper installed?

User avatar
macaqa
 
Posts: 2
Joined: Mon Dec 27, 2010 2:16 pm

Re: Motorboard LED function: Blinks only with forward/backward

Post by macaqa »

Thanks for a quick reply. Since there is no motor attached, I have not used external power source and the motorshield/arduino is powered off USB/9V battery powering arduino. And yes I have installed Ext_PWR jumpers but am not using them.

On further testing, attaching Ext Power to the motorshield keeps the LED on. Would I be correct in stating that the LED on the motorshield has two states:

Without Ext_Power: LED reflects the arduino output/frequency.
With Ext_Power: LED reflects input from Ext_Power.

Related quick question: Can the motorshield output be used to drive 1.5V DC motors e.g. using voltage divider (might be a really silly question) but am trying to use the motors I have for a robot rather than buying new ones.

Thanks!
Maq

Snowed in East Coast!

adafruit
 
Posts: 12151
Joined: Thu Apr 06, 2006 4:21 pm

Re: Motorboard LED function: Blinks only with forward/backward

Post by adafruit »

you CANNOT power motors off a 9V!
http://www.ladyada.net/make/mshield/faq.html
please read our entire user page
http://www.ladyada.net/make/mshield/use.html
you cannot use 1.5v motors

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