ManuelW/grbl-LPC-CoreXY
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PWM Library Working

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Currently the library works in SystemCoreClock/4 scale. So if you want a 1 second period, use period=SystemCoreClock / 4;
This commit is contained in:
Brett Fleming 2017-01-10 21:46:50 -05:00
parent c7a4b77e47
commit a4fc23ccad
2 changed files with 46 additions and 27 deletions
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57
smoother/pwm_driver.cpp
View File

@ -23,7 +23,7 @@
#include "pwm_driver.h"
#include "LPC17xx.h"
#include "grbl.h"
//#include "grbl.h"
//LPC_PWM1_BASE
//LPC_PWM1 is of type LPC_PWM_TypeDef at Address LPC_PWM1_BASE
@ -46,70 +46,81 @@
const PWM_Channel_Config PWM1_CH1 = {
&(LPC_PWM1->MR1), //Match Register
(1 << 9), //PWM Enable
(1 << 1) //Latch Enable Register
(1 << 1), //Latch Enable Register
(0x2 << 4), //PINSEL3 - P1.18
(0x1 << 0) //PINSEL4 - P2.0
};
const PWM_Channel_Config PWM1_CH2 = {
&(LPC_PWM1->MR2), //Match Register
(1 << 10), //PWM Enable
(1 << 2) //Latch Enable Register
(1 << 2), //Latch Enable Register
(0x2 << 8), //PINSEL3 - P1.20
(0x1 << 2) //PINSEL4 - P2.1
};
const PWM_Channel_Config PWM1_CH3 = {
&(LPC_PWM1->MR3), //Match Register
(1 << 11), //PWM Enable
(1 << 3) //Latch Enable Register
(1 << 3), //Latch Enable Register
(0x2 << 10), //PINSEL3 - P1.21
(0x1 << 4) //PINSEL4 - P2.2
};
const PWM_Channel_Config PWM1_CH4 = {
&(LPC_PWM1->MR4), //Match Register
(1 << 12), //PWM Enable
(1 << 4) //Latch Enable Register
(1 << 4), //Latch Enable Register
(0x2 << 14), //PINSEL3 - P1.23
(0x1 << 6) //PINSEL4 - P2.3
};
const PWM_Channel_Config PWM1_CH5 = {
&(LPC_PWM1->MR5), //Match Register
(1 << 13), //PWM Enable
(1 << 5) //Latch Enable Register
(1 << 5), //Latch Enable Register
(0x2 << 16), //PINSEL3 - P1.24
(0x1 << 8) //PINSEL4 - P2.4
};
const PWM_Channel_Config PWM1_CH6 = {
&(LPC_PWM1->MR6), //Match Register
(1 << 14), //PWM Enable
(1 << 6) //Latch Enable Register
(1 << 6), //Latch Enable Register
(0x2 << 20), //PINSEL3 - P1.26
(0x1 << 10) //PINSEL4 - P2.6
};
//Smoothie board uses P2.4 and P2.5 as PWM outputs
//UM10360 LPC17xx Chapter 24 - Pulse Width Modulation
//
// channel - Which of the 6 PWM channels to init.
// period - what is the overall period, in PCLK cycles, for ALL PWMs (not just the provided one)
//
void pwm_init(PWM_Channel_Config* channel, uint32_t period, uint32_t width) {
//Power up PCONP
void pwm_init(PWM_Channel_Config* channel, bool primaryPin, bool secondaryPin, uint32_t period, uint32_t width) {
//Match Control - Continous operation (no interrupts, no timer reset)
LPC_PWM1->MCR = 0x0000;
//Power up PWM Circuitry - Defaulted to on at reset, but doesn't hurt to make sure
LPC_SC->PCONP |= 1 << 6; // Power up the PWM
//PWM Control Register - Single Edge (0 for bits 2-6) mode for all PWMs
LPC_PWM1->PCR &= 0xFF00;
//Pin mode selections
if (primaryPin) LPC_PINCON->PINSEL3 |= channel->PINSEL3_Enable_Mask;
if (secondaryPin) LPC_PINCON->PINSEL4 |= channel->PINSEL4_Enable_Mask;
//PWM Control Register - Disable output for channel
LPC_PWM1->PCR &= ~channel->PCR_Enable_Mask;
//Match Control - Continous operation (no interrupts, reset counter on MSR0 match (period))
LPC_PWM1->MCR = (1 << 1);
//PWM Control Register - Single Edge (0 for bits 2-6) mode for all PWMs
LPC_PWM1->PCR &= 0xFF00;
//Disable Capture
LPC_PWM1->CCR = 0x0000;
//PWM Timer Control Register - Counter Enable, PWM Enable
LPC_PWM1->TCR = (1 << 0) | (1 << 3);
//PWM Counter Control Register - Use Timer Mode (Counter Mode is for external clocks, not PWM)
LPC_PWM1->CTCR = 0x0000;
LPC_PWM1->TCR = (1 << 0) | (1 << 2);
pwm_set_period(period);
pwm_set_width(channel, width);
@ -119,14 +130,14 @@ void pwm_set_period(uint32_t period) {
LPC_PWM1->MR0 = period;
//If we are running, this will make the MRx register on the next cycle
LPC_PWM1->LER = (1 << 0);
LPC_PWM1->LER = 0x00000001;
}
void pwm_set_width(PWM_Channel_Config* channel, uint32_t width) {
*(channel->MRn) = width;
//If we are running, this will make the MRx register on the next cycle
LPC_PWM1->LER |= channel->LER_Enable_Mask;
LPC_PWM1->LER = channel->LER_Enable_Mask;
}
void pwm_enable(PWM_Channel_Config* channel) {

14
smoother/pwm_driver.h
View File

@ -26,11 +26,19 @@ typedef struct _PWM_Channel_Config {
volatile uint32_t* MRn; //LPC_PWM1->MR1 through MR6
uint32_t PCR_Enable_Mask;
uint32_t LER_Enable_Mask;
} PWM_Channel_Config;
//PWM Output Mapping PWM1 PWM2 PWM3 PWM4 PWM5 PWM6
uint32_t PINSEL3_Enable_Mask; //For PWM support on (P1.18, P1.20, P1.21, P1.23, P1.24, P1.26)
uint32_t PINSEL4_Enable_Mask; //For PWM support on (P2.0, P2.1, P2.2, P2.3, P2.4, P2.6)
} const PWM_Channel_Config;
extern const PWM_Channel_Config PWM1_CH1;
extern PWM_Channel_Config PWM1_CH1;
extern PWM_Channel_Config PWM1_CH2;
extern PWM_Channel_Config PWM1_CH3;
extern PWM_Channel_Config PWM1_CH4;
extern PWM_Channel_Config PWM1_CH5;
extern PWM_Channel_Config PWM1_CH6;
void pwm_init(PWM_Channel_Config* channel, uint32_t period, uint32_t width);
void pwm_init(PWM_Channel_Config* channel, bool primaryPin, bool secondaryPin, uint32_t period, uint32_t width);
void pwm_set_period(uint32_t period);
void pwm_set_width(PWM_Channel_Config* channel, uint32_t width);
void pwm_enable(PWM_Channel_Config* channel);