circuitpython/stm/servo.c

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#include <stdio.h>
#include <stm32f4xx.h>
#include <stm32f4xx_rcc.h>
#include <stm32f4xx_gpio.h>
#include <stm32f4xx_tim.h>
#include "misc.h"
#include "mpconfig.h"
#include "obj.h"
#include "servo.h"
// PWM
// TIM2 and TIM5 have CH1, CH2, CH3, CH4 on PA0-PA3 respectively
// they are both 32-bit counters
// 16-bit prescaler
// TIM2_CH3 also on PB10 (used below)
void servo_init(void) {
// TIM2 clock enable
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
// for PB10
/*
// GPIOB Configuration: TIM2_CH3 (PB10)
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStructure);
// Connect TIM2 pins to AF1
GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_TIM2);
*/
// for PA0, PA1, PA2, PA3
{
// GPIOA Configuration: TIM2_CH0, TIM2_CH1 (PA0, PA1)
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
// Connect TIM2 pins to AF1
GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_TIM2);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource1, GPIO_AF_TIM2);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_TIM2);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_TIM2);
}
// Compute the prescaler value so TIM2 runs at 100kHz
uint16_t PrescalerValue = (uint16_t) ((SystemCoreClock / 2) / 100000) - 1;
// Time base configuration
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_TimeBaseStructure.TIM_Period = 2000; // timer cycles at 50Hz
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
// PWM Mode configuration
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 150; // units of 10us
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM2, &TIM_OCInitStructure); // channel 1
TIM_OC2Init(TIM2, &TIM_OCInitStructure); // channel 2
TIM_OC3Init(TIM2, &TIM_OCInitStructure); // channel 3
TIM_OC4Init(TIM2, &TIM_OCInitStructure); // channel 4
// ?
TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable); // channel 1
TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable); // channel 2
TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Enable); // channel 3
TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Enable); // channel 4
// ?
TIM_ARRPreloadConfig(TIM2, ENABLE);
// TIM2 enable counter
TIM_Cmd(TIM2, ENABLE);
}
/******************************************************************************/
/* Micro Python bindings */
mp_obj_t pyb_servo_set(mp_obj_t port, mp_obj_t value) {
int p = mp_obj_get_int(port);
int v = mp_obj_get_int(value);
if (v < 50) { v = 50; }
if (v > 250) { v = 250; }
switch (p) {
case 1: TIM2->CCR1 = v; break;
case 2: TIM2->CCR2 = v; break;
case 3: TIM2->CCR3 = v; break;
case 4: TIM2->CCR4 = v; break;
}
return mp_const_none;
}
mp_obj_t pyb_pwm_set(mp_obj_t period, mp_obj_t pulse) {
int pe = mp_obj_get_int(period);
int pu = mp_obj_get_int(pulse);
TIM2->ARR = pe;
TIM2->CCR3 = pu;
return mp_const_none;
}
typedef struct _pyb_servo_obj_t {
mp_obj_base_t base;
uint servo_id;
} pyb_servo_obj_t;
static void servo_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in) {
pyb_servo_obj_t *self = self_in;
print(env, "<Servo %lu>", self->servo_id);
}
static mp_obj_t servo_obj_angle(mp_obj_t self_in, mp_obj_t angle) {
pyb_servo_obj_t *self = self_in;
machine_int_t v = 152 + 85.0 * mp_obj_get_float(angle) / 90.0;
if (v < 65) { v = 65; }
if (v > 210) { v = 210; }
switch (self->servo_id) {
case 1: TIM2->CCR1 = v; break;
case 2: TIM2->CCR2 = v; break;
case 3: TIM2->CCR3 = v; break;
case 4: TIM2->CCR4 = v; break;
}
return mp_const_none;
}
static MP_DEFINE_CONST_FUN_OBJ_2(servo_obj_angle_obj, servo_obj_angle);
static const mp_obj_type_t servo_obj_type = {
{ &mp_const_type },
"Servo",
.print = servo_obj_print,
.methods = {
{ "angle", &servo_obj_angle_obj },
{ NULL, NULL },
}
};
mp_obj_t pyb_Servo(mp_obj_t servo_id) {
pyb_servo_obj_t *o = m_new_obj(pyb_servo_obj_t);
o->base.type = &servo_obj_type;
o->servo_id = mp_obj_get_int(servo_id);
return o;
}