From 605c30c0924952ee657b5ad4bd8347d4603159ad Mon Sep 17 00:00:00 2001 From: Unknown Date: Sun, 8 Jan 2017 20:55:11 -0500 Subject: [PATCH] PWM First draft at PWM driver. Needs testing, then merging into GRBL. --- smoother/pwm_driver.cpp | 141 ++++++++++++++++++++++++++++++++++++++++ smoother/pwm_driver.h | 38 +++++++++++ 2 files changed, 179 insertions(+) create mode 100644 smoother/pwm_driver.cpp create mode 100644 smoother/pwm_driver.h diff --git a/smoother/pwm_driver.cpp b/smoother/pwm_driver.cpp new file mode 100644 index 0000000..a002daa --- /dev/null +++ b/smoother/pwm_driver.cpp @@ -0,0 +1,141 @@ +// PWM Driver - LPC176x - Single edge only, does not support double edge PWM +// +// Copyright 2017 Brett Fleming +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS +// IN THE SOFTWARE. + +#include "pwm_driver.h" +#include "LPC17xx.h" + +#include "grbl.h" + +//LPC_PWM1_BASE +//LPC_PWM1 is of type LPC_PWM_TypeDef at Address LPC_PWM1_BASE + +/* + Theory of operation: Initialize, start running, change width any time while running. + + pwm_init(PWM1_CH1, 1000, 0); + pwm_enable(PWM1_CH1); + pwm_set_width(250); + sleep(1) + pwm_set_width(500); + sleep(1) + pwm_set_width(999); + sleep(1) + pwm_disable(PWM1_CH1); +*/ + + +const PWM_Channel_Config PWM1_CH1 = { + &(LPC_PWM1->MR1), //Match Register + (1 << 9), //PWM Enable + (1 << 1) //Latch Enable Register +}; + +const PWM_Channel_Config PWM1_CH2 = { + &(LPC_PWM1->MR2), //Match Register + (1 << 10), //PWM Enable + (1 << 2) //Latch Enable Register +}; + +const PWM_Channel_Config PWM1_CH3 = { + &(LPC_PWM1->MR3), //Match Register + (1 << 11), //PWM Enable + (1 << 3) //Latch Enable Register +}; + +const PWM_Channel_Config PWM1_CH4 = { + &(LPC_PWM1->MR4), //Match Register + (1 << 12), //PWM Enable + (1 << 4) //Latch Enable Register +}; + +const PWM_Channel_Config PWM1_CH5 = { + &(LPC_PWM1->MR5), //Match Register + (1 << 13), //PWM Enable + (1 << 5) //Latch Enable Register +}; + +const PWM_Channel_Config PWM1_CH6 = { + &(LPC_PWM1->MR6), //Match Register + (1 << 14), //PWM Enable + (1 << 6) //Latch Enable Register +}; + + + + +//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 + + //Match Control - Continous operation (no interrupts, no timer reset) + LPC_PWM1->MCR = 0x0000; + + //PWM Control Register - Single Edge (0 for bits 2-6) mode for all PWMs + LPC_PWM1->PCR &= 0xFF00; + + //PWM Control Register - Disable output for channel + LPC_PWM1->PCR &= ~channel->PCR_Enable_Mask; + + //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; + + pwm_set_period(period); + pwm_set_width(channel, width); +} + +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); +} + +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; +} + +void pwm_enable(PWM_Channel_Config* channel) { + //PWM Control Register - Enable output for channel + LPC_PWM1->PCR |= channel->PCR_Enable_Mask; +} + +void pwm_disable(PWM_Channel_Config* channel) { + //PWM Control Register - Disable output for channel + LPC_PWM1->PCR &= ~channel->PCR_Enable_Mask; +} + diff --git a/smoother/pwm_driver.h b/smoother/pwm_driver.h new file mode 100644 index 0000000..cd2ebc7 --- /dev/null +++ b/smoother/pwm_driver.h @@ -0,0 +1,38 @@ +// PWM Driver - LPC176x +// +// Copyright 2017 Brett Fleming +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS +// IN THE SOFTWARE. + +#include + +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; + +extern const PWM_Channel_Config PWM1_CH1; + +void pwm_init(PWM_Channel_Config* channel, 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); +void pwm_disable(PWM_Channel_Config* channel); +