File content as of revision 7:85b8b5acfb22:

#include <mbed.h>
#include "motors.h"

// Application     mbed pin    LPC1768
// Motor 1 PWM     p26         P2[0]/PWM1[1]
// Motor 1 dir     p25
// Motor 2 PWM     p27         P2[2]/PWM1[3]
// Motor 2 dir     p28

static PwmOut motor1Pwm(p26);
DigitalOut motor1Dir(p25);

static PwmOut motor2Pwm(p24);
DigitalOut motor2Dir(p23);

void motors_init()
{
    motor1Pwm.period_us(100);
    
    // Set most parts of the PWM module to their defaults.
    LPC_PWM1->TCR = 0;
    LPC_PWM1->CTCR = 0;
    LPC_PWM1->CCR = 0;
    
    // Enable PWM output 1 and PWM output 3.
    LPC_PWM1->PCR = (1 << 9) | (1 << 11);

    LPC_PWM1->MCR = (1 << 1);   // Reset PWMTC when it is equal to MR0.
    
    LPC_PWM1->MR0 = 1200;       // Set the period.  This must be done before enabling PWM.
    LPC_PWM1->LER = (1 << 0);
    motors_speed_set(0, 0);
    
    LPC_PWM1->TCR = (1 << 0) | (1 << 3);   // Enable the PWM counter and enable PWM.

}

void motors_speed_set(int16_t motor1_speed, int16_t motor2_speed)
{
    LPC_PWM1->MR1 = motor1_speed;
    LPC_PWM1->MR3 = motor2_speed;
    LPC_PWM1->LER |= (1<<1) | (1<<3);
}