This sketch is used by Exercise: DRV8833 Dual DC Motor Driver.
The full code is all in one file WheelDrive.ino.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | // WheelDrive - move a pair of DC motors at varying rate and direction
//
// Copyright (c) 2016, Garth Zeglin. All rights reserved. Licensed under the
// terms of the BSD 3-clause license as included in LICENSE.
//
// This program assumes that:
//
// 1. A DRV8833 dual DC motor driver module is connected to pins 5, 6, 9, and 10.
// 2. A pair of motors is attached to the driver.
// 3. The serial console on the Arduino IDE is set to 9600 baud communications speed.
// ================================================================================
// Define constant values and global variables.
// Define the pin numbers on which the outputs are generated.
#define MOT_A1_PIN 5
#define MOT_A2_PIN 6
#define MOT_B1_PIN 9
#define MOT_B2_PIN 10
// ================================================================================
/// Configure the hardware once after booting up. This runs once after pressing
//// reset or powering up the board.
void setup(void)
{
// Initialize the stepper driver control pins to output drive mode.
pinMode(MOT_A1_PIN, OUTPUT);
pinMode(MOT_A2_PIN, OUTPUT);
pinMode(MOT_B1_PIN, OUTPUT);
pinMode(MOT_B2_PIN, OUTPUT);
// Start with drivers off, motors coasting.
digitalWrite(MOT_A1_PIN, LOW);
digitalWrite(MOT_A2_PIN, LOW);
digitalWrite(MOT_B1_PIN, LOW);
digitalWrite(MOT_B2_PIN, LOW);
// Initialize the serial UART at 9600 bits per second.
Serial.begin(9600);
}
// ================================================================================
/// Set the current on a motor channel using PWM and directional logic.
/// Changing the current will affect the motor speed, but please note this is
/// not a calibrated speed control. This function will configure the pin output
/// state and return.
///
/// \param pwm PWM duty cycle ranging from -255 full reverse to 255 full forward
/// \param IN1_PIN pin number xIN1 for the given channel
/// \param IN2_PIN pin number xIN2 for the given channel
void set_motor_pwm(int pwm, int IN1_PIN, int IN2_PIN)
{
if (pwm < 0) { // reverse speeds
analogWrite(IN1_PIN, -pwm);
digitalWrite(IN2_PIN, LOW);
} else { // stop or forward
digitalWrite(IN1_PIN, LOW);
analogWrite(IN2_PIN, pwm);
}
}
// ================================================================================
/// Set the current on both motors.
///
/// \param pwm_A motor A PWM, -255 to 255
/// \param pwm_B motor B PWM, -255 to 255
void set_motor_currents(int pwm_A, int pwm_B)
{
set_motor_pwm(pwm_A, MOT_A1_PIN, MOT_A2_PIN);
set_motor_pwm(pwm_B, MOT_B1_PIN, MOT_B2_PIN);
// Print a status message to the console.
Serial.print("Set motor A PWM = ");
Serial.print(pwm_A);
Serial.print(" motor B PWM = ");
Serial.println(pwm_B);
}
// ================================================================================
/// Simple primitive for the motion sequence to set a speed and wait for an interval.
///
/// \param pwm_A motor A PWM, -255 to 255
/// \param pwm_B motor B PWM, -255 to 255
/// \param duration delay in milliseconds
void spin_and_wait(int pwm_A, int pwm_B, int duration)
{
set_motor_currents(pwm_A, pwm_B);
delay(duration);
}
// ================================================================================
/// Run one iteration of the main event loop. The Arduino system will call this
/// function over and over forever.
void loop(void)
{
// Generate a fixed motion sequence to demonstrate the motor modes.
// Ramp speed up.
for (int i = 0; i < 11; i++) {
spin_and_wait(25*i, 25*i, 500);
}
// Full speed forward.
spin_and_wait(255,255,2000);
// Ramp speed into full reverse.
for (int i = 0; i < 21 ; i++) {
spin_and_wait(255 - 25*i, 255 - 25*i, 500);
}
// Full speed reverse.
spin_and_wait(-255,-255,2000);
// Stop.
spin_and_wait(0,0,2000);
// Full speed, forward, turn, reverse, and turn for a two-wheeled base.
spin_and_wait(255, 255, 2000);
spin_and_wait(0, 0, 1000);
spin_and_wait(-255, 255, 2000);
spin_and_wait(0, 0, 1000);
spin_and_wait(-255, -255, 2000);
spin_and_wait(0, 0, 1000);
spin_and_wait(255, -255, 2000);
spin_and_wait(0, 0, 1000);
// and repeat
}
/****************************************************************/
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