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#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <stm32f4xx_hal.h>
#include "usbd_cdc_msc_hid.h"
#include "usbd_cdc_interface.h"
#include "nlr.h"
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
#include "timer.h"
#include "servo.h"
// The timers can be used by multiple drivers, and need a common point for
// the interrupts to be dispatched, so they are all collected here.
//
// TIM3:
// - USB CDC interface, interval, to check for new data
// - LED 4, PWM to set the LED intensity
//
// TIM5:
// - servo controller, PWM
TIM_HandleTypeDef TIM3_Handle;
TIM_HandleTypeDef TIM5_Handle;
TIM_HandleTypeDef TIM6_Handle;
// TIM3 is set-up for the USB CDC interface
void timer_tim3_init(void) {
// set up the timer for USBD CDC
__TIM3_CLK_ENABLE();
TIM3_Handle.Instance = TIM3;
TIM3_Handle.Init.Period = (USBD_CDC_POLLING_INTERVAL*1000) - 1;
TIM3_Handle.Init.Prescaler = 84-1;
TIM3_Handle.Init.ClockDivision = 0;
TIM3_Handle.Init.CounterMode = TIM_COUNTERMODE_UP;
HAL_TIM_Base_Init(&TIM3_Handle);
HAL_NVIC_SetPriority(TIM3_IRQn, 6, 0);
HAL_NVIC_EnableIRQ(TIM3_IRQn);
if (HAL_TIM_Base_Start(&TIM3_Handle) != HAL_OK) {
/* Starting Error */
}
}
/* unused
void timer_tim3_deinit(void) {
// reset TIM3 timer
__TIM3_FORCE_RESET();
__TIM3_RELEASE_RESET();
}
*/
// TIM5 is set-up for the servo controller
// This function inits but does not start the timer
void timer_tim5_init(void) {
// TIM5 clock enable
__TIM5_CLK_ENABLE();
// set up and enable interrupt
HAL_NVIC_SetPriority(TIM5_IRQn, 6, 0);
HAL_NVIC_EnableIRQ(TIM5_IRQn);
// PWM clock configuration
TIM5_Handle.Instance = TIM5;
TIM5_Handle.Init.Period = 2000; // timer cycles at 50Hz
TIM5_Handle.Init.Prescaler = ((SystemCoreClock / 2) / 100000) - 1; // timer runs at 100kHz
TIM5_Handle.Init.ClockDivision = 0;
TIM5_Handle.Init.CounterMode = TIM_COUNTERMODE_UP;
HAL_TIM_PWM_Init(&TIM5_Handle);
}
// Init TIM6 with a counter-overflow at the given frequency (given in Hz)
// TIM6 is used by the DAC and ADC for auto sampling at a given frequency
// This function inits but does not start the timer
void timer_tim6_init(uint freq) {
// TIM6 clock enable
__TIM6_CLK_ENABLE();
// Timer runs at SystemCoreClock / 2
// Compute the prescaler value so TIM6 triggers at freq-Hz
uint32_t period = (SystemCoreClock / 2) / freq;
uint32_t prescaler = 1;
while (period > 0xffff) {
period >>= 1;
prescaler <<= 1;
}
// Time base clock configuration
TIM6_Handle.Instance = TIM6;
TIM6_Handle.Init.Period = period - 1;
TIM6_Handle.Init.Prescaler = prescaler - 1;
TIM6_Handle.Init.ClockDivision = 0; // unused for TIM6
TIM6_Handle.Init.CounterMode = TIM_COUNTERMODE_UP; // unused for TIM6
HAL_TIM_Base_Init(&TIM6_Handle);
}
// Interrupt dispatch
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {
if (htim == &TIM3_Handle) {
USBD_CDC_HAL_TIM_PeriodElapsedCallback();
} else if (htim == &TIM5_Handle) {
servo_timer_irq_callback();
}
}
// below is old code from stm/ which has not yet been fully ported to stmhal/
#if 0
typedef struct _pyb_hal_tim_t {
mp_obj_base_t base;
TIM_HandleTypeDef htim;
} pyb_hal_tim_t;
pyb_hal_tim_t pyb_hal_tim_6;
pyb_hal_tim_6 = {
.base = {&pyb_type_hal_tim};
.htim = {TIM6
// TIM6 is used as an internal interrup to schedule something at a specific rate
mp_obj_t timer_py_callback;
mp_obj_t timer_py_set_callback(mp_obj_t f) {
timer_py_callback = f;
return mp_const_none;
}
mp_obj_t timer_py_set_period(mp_obj_t period) {
TIM6->ARR = mp_obj_get_int(period) & 0xffff;
return mp_const_none;
}
mp_obj_t timer_py_set_prescaler(mp_obj_t prescaler) {
TIM6->PSC = mp_obj_get_int(prescaler) & 0xffff;
return mp_const_none;
}
mp_obj_t timer_py_get_value(void) {
return mp_obj_new_int(TIM6->CNT & 0xfffff);
}
void timer_init(void) {
timer_py_callback = mp_const_none;
// TIM6 clock enable
__TIM6_CLK_ENABLE();
// Compute the prescaler value so TIM6 runs at 20kHz
uint16_t PrescalerValue = (uint16_t) ((SystemCoreClock / 2) / 20000) - 1;
// Time base configuration
tim_handle.Instance = TIM6;
tim_handle.Init.Prescaler = PrescalerValue;
tim_handle.Init.CounterMode = TIM_COUNTERMODE_UP; // unused for TIM6
tim_handle.Init.Period = 20000; // timer cycles at 1Hz
tim_handle.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1; // unused for TIM6
tim_handle.Init.RepetitionCounter = 0; // unused for TIM6
HAL_TIM_Base_Init(&tim_handle);
// enable perhipheral preload register
//TIM_ARRPreloadConfig(TIM6, ENABLE); ??
// set up interrupt
HAL_NVIC_SetPriority(TIM6_DAC_IRQn, 0xf, 0xf); // lowest priority
HAL_NVIC_EnableIRQ(TIM6_DAC_IRQn);
// start timer, so that it interrupts on overflow
HAL_TIM_Base_Start_IT(&tim_handle);
// Python interface
mp_obj_t m = mp_obj_new_module(QSTR_FROM_STR_STATIC("timer"));
rt_store_attr(m, QSTR_FROM_STR_STATIC("callback"), rt_make_function_n(1, timer_py_set_callback));
rt_store_attr(m, QSTR_FROM_STR_STATIC("period"), rt_make_function_n(1, timer_py_set_period));
rt_store_attr(m, QSTR_FROM_STR_STATIC("prescaler"), rt_make_function_n(1, timer_py_set_prescaler));
rt_store_attr(m, QSTR_FROM_STR_STATIC("value"), rt_make_function_n(0, timer_py_get_value));
rt_store_name(QSTR_FROM_STR_STATIC("timer"), m);
}
void timer_interrupt(void) {
if (timer_py_callback != mp_const_none) {
nlr_buf_t nlr;
if (nlr_push(&nlr) == 0) {
// XXX what to do if the GC is in the middle of running??
rt_call_function_0(timer_py_callback);
nlr_pop();
} else {
// uncaught exception
printf("exception in timer interrupt\n");
mp_obj_print((mp_obj_t)nlr.ret_val, PRINT_REPR);
printf("\n");
}
}
}
mp_obj_t pyb_Timer(mp_obj_t timx_in) {
TIM_TypeDef *TIMx = (TIM_TypeDef*)mp_obj_get_int(timx_in);
if (!IS_TIM_INSTANCE(TIMx)) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "argument 1 is not a TIM instance"));
}
pyb_hal_tim_t *tim = m_new_obj(pyb_hal_tim_t);
tim->htim.Instance = TIMx;
tim->htim.Instance.Init.Prescaler = x;
tim->htim.Instance.Init.CounterMode = y;
tim->htim.Instance.Init.Period = y;
tim->htim.Instance.Init.ClockDivision = y;
tim->htim.Instance.Init.RepetitionCounter = y;
HAL_TIM_Base_Init(&tim->htim);
return tim;
}
#endif
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