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AdaFruit Motor Shield Utiliser (voir la source)

Version du 17 décembre 2012 à 11:56

8 551 octets ajoutés ,  17 décembre 2012 à 11:56
→‎How to set up the Arduino + Shield for powering motors
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[[Fichier:ADF-MOTOR-SHIELD-USE-ALIM.jpg]]
 
[[Fichier:ADF-MOTOR-SHIELD-USE-ALIM.jpg]]
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If you would like to have a '''single DC power supply for the Arduino and motors''', simply plug it into the DC jack on the Arduino or the 2-pin PWR_EXT block on the shield. Place the power jumper on the motor shield.
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If you have a Diecimila Arduino, set the Arduino power source jumper to EXT.
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Note that you may have problems with Arduino resets if the battery supply is not able to provide constant power, and it is not a suggested way of powering your motor project
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If you would like to have the '''Arduino powered off of USB''' and '''the motors powered off of a DC power supply''', plug in the USB cable. Then connect the motor supply to the PWR_EXT block on the shield. Do not place the jumper on the shield. This is a suggested method of powering your motor project
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(If you have a Diecimila Arduino, don't forget to set the Arduino power jumper to USB. If you have a Diecimila, you can alternately do the following: plug the DC power supply into the Arduino, and place the jumper on the motor shield.)
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If you would like to have '''2 seperate DC power supplies for the Arduino and motors'''. Plug in the supply for the Arduino into the DC jack, and connect the motor supply to the PWR_EXT block. Make sure the jumper is removed from the motor shield.
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If you have a Diecimila Arduino, set the Arduino jumper to EXT. This is a suggested method of powering your motor project
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Either way, if you want to use the DC motor/Stepper system the motor shield LED should be lit indicating good motor power
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== Servo Moteur ==
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[[Fichier:ADF-MOTOR-SHIELD-USE-SERVO.jpg]]
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Hobby servos are the easiest way to get going with motor control. They have a 3-pin 0.1" female header connection with +5V, ground and signal inputs. The motor shield simply brings out the 16bit PWM output lines to 2 3-pin headers so that its easy to plug in and go. They can take a lot of power so a 9V battery wont last more than a few minutes!
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The nice thing about using the onboard PWM is that its very precise and goes about its business in the background. You can use the built in Servo library
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[http://www.arduino.cc/en/Reference/Servo Using the servos is easy, please read the official Arduino documentation for how to use them and see the example Servo sketches in the IDE]
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== Moteur Continu ==
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[[Fichier:ADF-MOTOR-SHIELD-USE-MOTEURCC.jpg]]
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DC motors are used for all sort of robotic projects. The motor shield can drive up to 4 DC motors bi-directionally. That means they can be driven forwards and backwards. The speed can also be varied at 0.5% increments using the high-quality built in PWM. This means the speed is very smooth and won't vary!
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Note that the H-bridge chip is not really meant for driving loads over 0.6A or that peak over 1.2A so this is for small motors. Check the datasheet for information about the motor to verify its OK.
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To connect a motor, simply solder two wires to the terminals and then connect them to either the '''M1, M2, M3,''' or '''M4'''. Then follow these steps in your sketch
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# Make sure you include <AFMotor.h>
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# Create the AF_DCMotor object with '''AF_DCMotor(motor#, frequency)''', to setup the motor H-bridge and latches. The constructor takes two arguments.
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    The first is which port the motor is connected to, '''1, 2, 3''' or '''4'''.
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  ''' ''frequency''' '' is how fast the speed controlling signal is.
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    For motors 1 and 2 you can choose '''MOTOR12_64KHZ, MOTOR12_8KHZ, MOTOR12_2KHZ''', or '''MOTOR12_1KHZ'''. A high speed like 64KHz wont be audible but a low speed like 1KHz will use less power. Motors 3 & 4 are only possible to run at 1KHz and will ignore any setting given
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# Then you can set the speed of the motor using '''setSpeed(speed)''' where the ''speed'' ranges from 0 (stopped) to 255 (full speed). You can set the speed whenever you want.
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# To run the motor, call '''run(direction)''' where direction is '''FORWARD, BACKWARD''' or '''RELEASE'''. Of course, the Arduino doesn't actually know if the motor is 'forward' or 'backward', so if you want to change which way it thinks is forward, simply swap the two wires from the motor to the shield.
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<nowiki>#include <AFMotor.h>
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AF_DCMotor motor(2, MOTOR12_64KHZ); // create motor #2, 64KHz pwm
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void setup() {
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  Serial.begin(9600);          // set up Serial library at 9600 bps
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  Serial.println("Motor test!");
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  motor.setSpeed(200);    // set the speed to 200/255
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}
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void loop() {
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  Serial.print("tick");
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  motor.run(FORWARD);      // turn it on going forward
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  delay(1000);
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  Serial.print("tock");
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  motor.run(BACKWARD);    // the other way
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  delay(1000);
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  Serial.print("tack");
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  motor.run(RELEASE);      // stopped
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  delay(1000);
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}</nowiki>
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== Moteur pas-à-pas ==
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Voici un exemple avec un moteur pas-à-pas bipolaire.
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[[Fichier:ADF-MOTOR-SHIELD-USE-BIPOLAR-STEPPER.jpg]]
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Stepper motors are great for (semi-)precise control, perfect for many robot and CNC projects. This motor shield supports up to 2 stepper motors. The library works identically for bi-polar and uni-polar motors
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For unipolar motors: to connect up the stepper, first figure out which pins connected to which coil, and which pins are the center taps. If its a 5-wire motor then there will be 1 that is the center tap for both coils. [http://www.ladyada.net/make/mshield/resources.html Theres plenty of tutorials online on how to reverse engineer the coils pinout]. The center taps should both be connected together to the GND terminal on the motor shield output block. then coil 1 should connect to one motor port (say M1 or M3) and coil 2 should connect to the other motor port (M2 or M4).
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For bipolar motors: its just like unipolar motors except theres no 5th wire to connect to ground. The code is exactly the same.
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Running a stepper is a little more intricate than running a DC motor but its still very
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easy
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# Make sure you include <AFMotor.h>
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# Create the stepper motor object with '''AF_Stepper(steps, stepper#)''' to setup the motor H-bridge and latches.'' '''Steps''' '' indicates how many steps per revolution the motor has. a 7.5degree/step motor has 360/7.5 = 48 steps.'' '''Stepper#''' '' is which port it is connected to. If you're using M1 and M2, its port 1. If you're using M3 and M4 its port 2
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# Set the speed of the motor using '''setSpeed(rpm)''' where '' '''rpm''' '' is how many revolutions per minute you want the stepper to turn.
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# Then every time you want the motor to move, call the '''step(#steps, direction, steptype)''' procedure. '' '''#steps''' '' is how many steps you'd like it to take. direction is either '''FORWARD''' or '''BACKWARD''' and the step type is '''SINGLE, DOUBLE. INTERLEAVE''' or '''MICROSTEP'''.
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    "Single" means single-coil activation, "double" means 2 coils are activated at once (for higher torque) and "interleave" means that it alternates between single and double to get twice the resolution (but of course its half the speed). "Microstepping" is a method where the coils are PWM'd to create smooth motion between steps. [http://www.ladyada.net/make/mshield/resources.html Theres tons of information about the pros and cons of these different stepping methods in the resources page].<br />
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You can use whichever stepping method you want, changing it "on the fly" to as you may want minimum power, more torque, or more precision.
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# By default, the motor will 'hold' the position after its done stepping. If you want to release all the coils, so that it can spin freely, call '''release()'''
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# The stepping commands are 'blocking' and will return once the steps have finished. If someone wants to be awesome and write a version of the library that does background stepping that would be cool! :)
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<nowiki>#include <AFMotor.h>
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AF_Stepper motor(48, 2);
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void setup() {
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  Serial.begin(9600);          // set up Serial library at 9600 bps
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  Serial.println("Stepper test!");
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  motor.setSpeed(10);  // 10 rpm 
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  motor.step(100, FORWARD, SINGLE);
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  motor.release();
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  delay(1000);
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}
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void loop() {
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  motor.step(100, FORWARD, SINGLE);
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  motor.step(100, BACKWARD, SINGLE);
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  motor.step(100, FORWARD, DOUBLE);
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  motor.step(100, BACKWARD, DOUBLE);
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  motor.step(100, FORWARD, INTERLEAVE);
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  motor.step(100, BACKWARD, INTERLEAVE);
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  motor.step(100, FORWARD, MICROSTEP);
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  motor.step(100, BACKWARD, MICROSTEP);
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}</nowiki>
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If you want two stepper motors to step at once you'll need to write something like this:
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<nowiki>void doublestep (int steps, int direction, int style) {
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  while (steps--) {
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    motor1.step(1, direction, style);
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    motor2.step(1, direction, style);
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  }
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}</nowiki>
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Récupérée de « https://wiki.mchobby.be/index.php?title=Spécial:MobileDiff/2528 »

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