David Grayson / Mbed 2 deprecated DeadReckoning

David's dead reckoning code for the LVBots competition on March 6th. Uses the mbed LPC1768, DRV8835, QTR-3RC, and two DC motors with encoders.

Dependencies:   PololuEncoder Pacer mbed GeneralDebouncer

motors.cpp@9:9734347b5756, 2014-02-22 (annotated)

Committer:
DavidEGrayson
Date:
Sat Feb 22 03:03:37 2014 +0000
Revision:
9:9734347b5756
Parent:
8:78b1ff957cba
Child:
32:83a13b06093c
Made verything use CamelCase.;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
DavidEGrayson 4:1b20a11765c8 1 #include <mbed.h>
DavidEGrayson 7:85b8b5acfb22 2 #include "motors.h"
DavidEGrayson 7:85b8b5acfb22 3
DavidEGrayson 7:85b8b5acfb22 4 // Application mbed pin LPC1768
DavidEGrayson 9:9734347b5756 5 // Motor L PWM p26 P2[0]/PWM1[1]
DavidEGrayson 9:9734347b5756 6 // Motor L dir p25
DavidEGrayson 9:9734347b5756 7 // Motor R PWM p24 P2[2]/PWM1[3]
DavidEGrayson 9:9734347b5756 8 // Motor R dir p23
DavidEGrayson 4:1b20a11765c8 9
DavidEGrayson 8:78b1ff957cba 10 // Clock structure:
DavidEGrayson 8:78b1ff957cba 11 // System clock: 96 MHz
DavidEGrayson 8:78b1ff957cba 12 // In LPC_SC->PCLKSEL0, PWM is assigned to system clock / 4 by default, so it ticks at 24 MHz.
DavidEGrayson 8:78b1ff957cba 13 // This allows us to have 1200 possible speeds at 20 kHz.
DavidEGrayson 8:78b1ff957cba 14
DavidEGrayson 9:9734347b5756 15 DigitalOut motorLeftDir(p25);
DavidEGrayson 9:9734347b5756 16 DigitalOut motorRightDir(p23);
DavidEGrayson 4:1b20a11765c8 17
DavidEGrayson 9:9734347b5756 18 void motorsInit()
DavidEGrayson 4:1b20a11765c8 19 {
DavidEGrayson 8:78b1ff957cba 20 //PwmOut(p26).period_us(100);
DavidEGrayson 8:78b1ff957cba 21
DavidEGrayson 8:78b1ff957cba 22 // Power the PWM module by setting PCPWM1 bit in PCONP register. (Table 46).
DavidEGrayson 8:78b1ff957cba 23 LPC_SC->PCONP |= (1 << 6);
DavidEGrayson 8:78b1ff957cba 24
DavidEGrayson 8:78b1ff957cba 25 // In PCLKSEL0 register, set the clock for PWM1 to be equal to CCLK/4 (96/4 = 24 MHz).
DavidEGrayson 8:78b1ff957cba 26 LPC_SC->PCLKSEL0 &= ~(3 << 12);
DavidEGrayson 8:78b1ff957cba 27
DavidEGrayson 8:78b1ff957cba 28 // Select the functions of P2.0 and P2.2 as PWM. (Table 83).
DavidEGrayson 8:78b1ff957cba 29 LPC_PINCON->PINSEL4 = (LPC_PINCON->PINSEL4 & ~((3 << 0) | (3 << 4))) | ((1 << 0) | (1 << 4));
DavidEGrayson 7:85b8b5acfb22 30
DavidEGrayson 7:85b8b5acfb22 31 // Set most parts of the PWM module to their defaults.
DavidEGrayson 7:85b8b5acfb22 32 LPC_PWM1->TCR = 0;
DavidEGrayson 7:85b8b5acfb22 33 LPC_PWM1->CTCR = 0;
DavidEGrayson 7:85b8b5acfb22 34 LPC_PWM1->CCR = 0;
DavidEGrayson 5:01ad080dc4fa 35
DavidEGrayson 7:85b8b5acfb22 36 // Enable PWM output 1 and PWM output 3.
DavidEGrayson 7:85b8b5acfb22 37 LPC_PWM1->PCR = (1 << 9) | (1 << 11);
DavidEGrayson 7:85b8b5acfb22 38
DavidEGrayson 5:01ad080dc4fa 39 LPC_PWM1->MCR = (1 << 1); // Reset PWMTC when it is equal to MR0.
DavidEGrayson 7:85b8b5acfb22 40
DavidEGrayson 7:85b8b5acfb22 41 LPC_PWM1->MR0 = 1200; // Set the period. This must be done before enabling PWM.
DavidEGrayson 7:85b8b5acfb22 42 LPC_PWM1->LER = (1 << 0);
DavidEGrayson 9:9734347b5756 43 motorsSpeedSet(0, 0);
DavidEGrayson 7:85b8b5acfb22 44
DavidEGrayson 7:85b8b5acfb22 45 LPC_PWM1->TCR = (1 << 0) | (1 << 3); // Enable the PWM counter and enable PWM.
DavidEGrayson 4:1b20a11765c8 46 }
DavidEGrayson 4:1b20a11765c8 47
DavidEGrayson 9:9734347b5756 48 void motorsSpeedSet(int16_t motorLeftSpeed, int16_t motorRightSpeed)
DavidEGrayson 4:1b20a11765c8 49 {
DavidEGrayson 9:9734347b5756 50 if (motorLeftSpeed < 0)
DavidEGrayson 8:78b1ff957cba 51 {
DavidEGrayson 9:9734347b5756 52 motorLeftSpeed = -motorLeftSpeed;
DavidEGrayson 9:9734347b5756 53 motorLeftDir = 0;
DavidEGrayson 8:78b1ff957cba 54 }
DavidEGrayson 8:78b1ff957cba 55 else
DavidEGrayson 8:78b1ff957cba 56 {
DavidEGrayson 9:9734347b5756 57 motorLeftDir = 1;
DavidEGrayson 8:78b1ff957cba 58 }
DavidEGrayson 9:9734347b5756 59 LPC_PWM1->MR1 = motorLeftSpeed;
DavidEGrayson 8:78b1ff957cba 60
DavidEGrayson 9:9734347b5756 61 if (motorRightSpeed < 0)
DavidEGrayson 8:78b1ff957cba 62 {
DavidEGrayson 9:9734347b5756 63 motorRightSpeed = -motorRightSpeed;
DavidEGrayson 9:9734347b5756 64 motorRightDir = 0;
DavidEGrayson 8:78b1ff957cba 65 }
DavidEGrayson 8:78b1ff957cba 66 else
DavidEGrayson 8:78b1ff957cba 67 {
DavidEGrayson 9:9734347b5756 68 motorRightDir = 1;
DavidEGrayson 8:78b1ff957cba 69 }
DavidEGrayson 9:9734347b5756 70 LPC_PWM1->MR3 = motorRightSpeed;
DavidEGrayson 8:78b1ff957cba 71
DavidEGrayson 7:85b8b5acfb22 72 LPC_PWM1->LER |= (1<<1) | (1<<3);
DavidEGrayson 4:1b20a11765c8 73 }