restructuring

deprecated/F1/distance_meters/ultrasonic.c

@@ -0,0 +1,165 @@
+/*
+ * ultrasonic.c
+ *
+ * Copyright 2015 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <libopencm3/stm32/timer.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/cm3/nvic.h>
+
+#include "ultrasonic.h"
+#include "user_proto.h"
+
+static usmode US_mode = US_MODE_OFF;
+static int overcapture = 0;
+
+#ifndef TIM_CCMR2_CC3S_IN_TI4
+#define TIM_CCMR2_CC3S_IN_TI4		(2)
+#endif
+#ifndef TIM_CCMR2_CC4S_IN_TI4
+#define TIM_CCMR2_CC4S_IN_TI4		(1 << 8)
+#endif
+/**
+ * Init timer 2 (&remap channels 3&4 to five-tolerant ports)
+ */
+void tim2_init(){
+	// Turn off JTAG & SWD, remap TIM2_CH3/TIM2_CH4 to PB10/PB11 (five tolerant)
+	// don't forget about AFIO clock & PB clock!
+	rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN | RCC_APB2ENR_IOPBEN);
+	gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_OFF, AFIO_MAPR_TIM2_REMAP_PARTIAL_REMAP2);
+	// setup PB10 & PB11
+	// PB10 - Trig output - push/pull
+	gpio_set_mode(GPIO_BANK_TIM2_PR2_CH3, GPIO_MODE_OUTPUT_10_MHZ,
+		GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_TIM2_PR2_CH3);
+//	gpio_set_mode(GPIO_BANK_TIM2_CH3, GPIO_MODE_OUTPUT_10_MHZ,
+//		GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_TIM2_CH3);
+	// PB11 - Echo input - floating
+//	gpio_set_mode(GPIO_BANK_TIM2_PR2_CH4, GPIO_MODE_INPUT,
+//		GPIO_CNF_INPUT_FLOAT, GPIO_TIM2_PR2_CH4);
+	rcc_periph_clock_enable(RCC_TIM2);
+	timer_reset(TIM2);
+	// timers have frequency of 1MHz -- 1us for one step
+	// 36MHz of APB1
+	timer_set_mode(TIM2, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
+	// 72MHz div 72 = 1MHz
+	TIM2_PSC = 71;  // prescaler is (div - 1)
+	TIM2_ARR = TRIG_T;
+	TIM2_CCR3 = TRIG_L;
+//	DBG("Timer configured\n");
+}
+
+/**
+ * Send Trig signal
+ * return 0 if another measurement still in process
+ */
+int start_ultrasonic(){
+	if(US_mode != US_MODE_OFF && US_mode != US_MODE_READY) return 0;
+	overcapture = 0;
+	TIM2_CR1 = 0;
+	//TIM2_CR1 = TIM_CR1_URS; // Turn off timer to reconfigure, dusable UEV by UG set
+	TIM2_CCER = 0;
+	TIM2_CCMR2 = 0;
+	TIM2_DIER = 0;
+	TIM2_SR = 0; // clear all flags
+	TIM2_ARR = TRIG_T;
+	TIM2_CCR3 = TRIG_L;
+	// PWM_OUT for TIM2_CH3
+	TIM2_CCMR2 = TIM_CCMR2_CC3S_OUT | TIM_CCMR2_OC3M_PWM1;
+	// start measurement, active is high
+	TIM2_CCER = TIM_CCER_CC3E;
+	// enable CC3 IRQ
+	TIM2_DIER = TIM_DIER_CC3IE;
+	nvic_enable_irq(NVIC_TIM2_IRQ);
+	US_mode = US_MODE_TRIG;
+	// start timer in one-pulse mode without update event
+	TIM2_CR1 = TIM_CR1_OPM | TIM_CR1_CEN | TIM_CR1_UDIS;
+	return 1;
+}
+
+/**
+ * Start measurement:
+ * TIM2_CH3 will capture high level & TIM2_CH4 will capture low
+ * The timer configured to 65536us to detect signal lost
+ */
+inline void run_measrmnt(){
+	US_mode = US_MODE_WAIT;
+	TIM2_CR1 = 0; // Turn off timer to reconfigure
+	TIM2_DIER = 0;
+	TIM2_CCER = 0;
+	TIM2_CCMR2 = 0;
+	//DBG("triggered\n");
+	TIM2_SR = 0; // clear all flags
+	TIM2_ARR = MAX_MSRMNT_LEN;
+	// TIM2_CH3 & TIM2_CH4 configured as inputs, TIM2_CH3 connected to CH4
+	TIM2_CCMR2 = TIM_CCMR2_CC3S_IN_TI4 | TIM_CCMR2_CC4S_IN_TI4;
+	// start
+	TIM2_CCER = TIM_CCER_CC4P | TIM_CCER_CC4E | TIM_CCER_CC3E;
+	// enable interrupts CH3, CH4 & update
+	TIM2_DIER = TIM_DIER_CC3IE | TIM_DIER_CC4IE | TIM_DIER_UIE;
+	// start timer in one-pulse mode
+	TIM2_CR1 = TIM_CR1_OPM | TIM_CR1_CEN;
+}
+
+void tim2_isr(){
+	// No signal
+	if(TIM2_SR & TIM_SR_UIF){ // update interrupt
+		TIM2_SR = 0;
+		overcapture = 1;
+		nvic_disable_irq(NVIC_TIM2_IRQ);
+		TIM2_DIER = 0;
+		US_mode = US_MODE_READY;
+		DBG("overcaptured\n");
+	}
+	// end of Trig pulse or start of measurements
+	if(TIM2_SR & TIM_SR_CC3IF){ // CCR ch3 interrupt
+		if(US_mode == US_MODE_TRIG){ // triggered - run measurement
+			run_measrmnt();
+		}else if(US_mode == US_MODE_WAIT){
+			US_mode = US_MODE_MEASUREMENT;
+		}
+		TIM2_SR &= ~TIM_SR_CC3IF;
+	}
+	if(TIM2_SR & TIM_SR_CC4IF){
+		if(US_mode == US_MODE_MEASUREMENT){
+			US_mode = US_MODE_READY;
+			nvic_disable_irq(NVIC_TIM2_IRQ);
+			TIM2_DIER = 0;
+			TIM2_CR1 = 0; // turn off timer - we don't need it more
+		}
+		TIM2_SR &= ~TIM_SR_CC3IF;
+	}
+}
+
+/**
+ * Measure distance
+ * return 1 if measurements done
+ * set L to distance (in mm) or 0 in case of overcapture (no signal)
+ */
+int ultrasonic_get(uint32_t *L){
+	uint32_t D;
+	if(US_mode != US_MODE_READY)
+		return 0;
+	US_mode = US_MODE_OFF;
+	if(!overcapture){
+		D = ((uint32_t)(TIM2_CCR4 - TIM2_CCR3)) * 170;
+		*L = D / 1000;
+	}else *L = 0;
+	return 1;
+}