removed garbage, added readme

Makefile

@@ -24,7 +24,6 @@ OBJS += utils/nvic.o
 OBJS += utils/str_utils.o
 OBJS += init.o
 OBJS += blink.o
-OBJS += capture.o
 OBJS += lib/common.o
 
 ################################################################

README.md

@@ -0,0 +1,3 @@
+This is a bootstrap project for programming STM32L100 without any external libs (with just libc).
+
+It uses `arm-none-eabi-gcc` and is written for STM32L100C-DISCOVERY.

capture.c

@@ -1,77 +0,0 @@
-#include "capture.h"
-#include "utils/timebase.h"
-#include <math.h>
-
-uint16_t adc_measure(uint8_t channel)
-{
-	ADC1_SQR5 = channel; // select n-th channel
-	ADC1_SQR1 = 0; // sets length to 1 (0000)
-
-	ADC1_CR2 |= ADC_CR2_SWSTART; // start conversion
-
-	// wait for end of conversion
-	while (!(ADC1_SR & ADC_SR_EOC));
-	return ADC1_DR;
-}
-
-
-float measure_angle(void)
-{
-	uint16_t d = adc_measure(18);
-	return -135 + 270 * (d / 4095.0f);
-}
-
-
-float measure_exposure(void)
-{
-	uint16_t d = adc_measure(8);
-	float alpha = d / 4095.0f;
-	return alpha * 100; // %
-}
-
-
-float measure_resistance(void)
-{
-	uint16_t d = adc_measure(9);
-
-	float alpha = d / 4095.0f;
-	float ref_r = 330;
-
-	return (ref_r * alpha) / (1 - alpha);
-}
-
-
-float measure_temp(void)
-{
-	uint16_t ts_data = adc_measure(ADC_CH_TEMP);
-
-	// temperature calibration constants for L100 are undocumented,
-	// probably because the sensor is broken.
-
-	// Temperature sensor is unstable and unreliable.
-
-	uint16_t ts_cal1 = MMIO16(0x1FF800FA);
-	uint16_t ts_cal2 = MMIO16(0x1FF800FE);
-
-	return ((80.0f / (ts_cal2 - ts_cal1)) * (ts_data - ts_cal1) + 30.0f);
-}
-
-
-void pwm2_set_frequency(float hz)
-{
-	float core_clk = 16000000 / 2.0f; // prescaller
-
-	float cnt = core_clk / hz;
-
-	uint32_t div = (uint32_t)cnt;
-
-	if (hz < 150) {
-		div /= 8;
-		TIM2_PSC = 15;
-	} else {
-		TIM2_PSC = 1;
-	}
-
-	TIM2_ARR = div; // sets frequency
-	TIM2_CCR2 = TIM2_ARR/2; // duty cycle
-}

capture.h

@@ -1,10 +0,0 @@
-#pragma once
-#include <common.h>
-
-uint16_t adc_measure(uint8_t channel);
-float measure_temp(void);
-float measure_angle(void);
-float measure_resistance(void);
-float measure_exposure(void);
-
-void pwm2_set_frequency(float hz);

doc/controls.txt

@@ -1,3 +0,0 @@
-b,d - změna střídy PWM, krok 50 (rozsah 0-1000)
-m,n - změna hodnoty DAC, krok 117 (rozsah 0-4095)
-g - nulovat počítadlo závory

doc/output.txt

@@ -1 +0,0 @@
-T -179.6°C | An -6.6° | R 589.2 | L 1.8% | G 0, #0 | DA 4095 | PWM 1000

init.c

@@ -4,17 +4,15 @@
 #include "utils/usart.h"
 #include "utils/nvic.h"
 
+// This file contains examples of initializing some peripherals
+
 
 void init_gpios(void)
 {
-	gpio_enable(GPIOA);
-	gpio_enable(GPIOB);
 	gpio_enable(GPIOC);
 
 	// LEDs
 	gpio_set_mode(GPIOC, BIT8 | BIT9, MODER_OUTPUT);
-
-	gpio_set_mode(GPIOC, BIT11, MODER_INPUT);
 }
 
 
@@ -42,7 +40,7 @@ void init_usart(void)
 {
 	gpio_set_af(GPIOA, BIT2 | BIT3, AF7);
 
-	// USART at A2 (tx), A3 (rx)
+	// USART2 at A2 (tx), A3 (rx)
 	RCC_APB1ENR |= RCC_APB1ENR_USART2EN;
 
 	// RATE 9600Bd 104.1875 (see datasheet for reference)
@@ -61,24 +59,18 @@ void init_usart(void)
 
 void init_systick(void)
 {
-	//SysTick_CSR = (SysTick_CSR & ~SysTick_CSR_CLKSOURCE) | (1 << __CTZ(SysTick_CSR_CLKSOURCE));
-
 	patch_register(SysTick_CSR, SysTick_CSR_CLKSOURCE, 1); // 1 - core, 0 - div 8
 
 	SysTick_RELOAD = 16000; // 1ms interrupt @ 16MHz core clock
 	SysTick_CSR |= SysTick_CSR_TICKINT | SysTick_CSR_ENABLE;
 }
 
+// ----
+
 
 void init_adc(void)
 {
-	// B1 ... AN9   Vcc o--[330R]--(B1)--[?R]--| GND
+	gpio_set_mode(GPIOB, BIT1 | BIT0 | BIT12, MODER_ANALOG); // configure pins you want to use
-	// B0 ... AN8   fototransistor
-	// B12 .. AN18  "angle" potentiometer
-	// C5 ... AN15
-
-	gpio_set_mode(GPIOB, BIT1 | BIT0 | BIT12, MODER_ANALOG);
-	//gpio_set_mode(GPIOC, BIT5, MODER_ANALOG);
 
 	// enable clock for ADC
 	RCC_APB2ENR |= RCC_APB2ENR_ADC1EN;
@@ -98,6 +90,22 @@ void init_adc(void)
 	while (!(ADC1_SR & ADC_SR_ADONS));
 }
 
+// EXAMPLE to measure an ADC channel
+uint16_t adc_measure(uint8_t channel)
+{
+	ADC1_SQR5 = channel; // select n-th channel
+	ADC1_SQR1 = 0; // sets length to 1 (0000)
+
+	ADC1_CR2 |= ADC_CR2_SWSTART; // start conversion
+
+	// wait for end of conversion
+	while (!(ADC1_SR & ADC_SR_EOC));
+	return ADC1_DR;
+}
+
+
+// ----
+
 
 void init_dac(void)
 {
@@ -117,7 +125,7 @@ void init_pwm1(void)
 	RCC_APB1ENR |= RCC_APB1ENR_TIM3EN;
 
 	// using timer 3, channel 1
-	gpio_set_af(GPIOA, BIT6, AF2);
+	gpio_set_af(GPIOA, BIT6, AF2); // A6 PWM output
 
 	patch_register(TIM3_CCMR1, TIM_CCMR1_OC1M, TIM_OCM_PWM1); // set PWM1 mode
 
@@ -139,51 +147,3 @@ void init_pwm1(void)
 
 	TIM3_CR1 |= TIM_CR1_CEN; // enable timer.
 }
-
-
-// pwm with variable frequency
-void init_pwm2(void)
-{
-	// enable clock for the timer
-	RCC_APB1ENR |= RCC_APB1ENR_TIM2EN;
-
-	// using timer 2, channel 2 - PA1
-	gpio_set_af(GPIOA, BIT1, AF1);
-
-	patch_register(TIM2_CCMR1, TIM_CCMR1_OC2M, TIM_OCM_PWM1); // set PWM1 mode
-
-	TIM2_CCMR1 |= TIM_CCMR1_OC2PE; // preload enable
-	TIM2_CR1 |= TIM_CR1_ARPE; // auto reload is buffered
-	TIM2_CCER |= TIM_CCER_CC2E; // enable output compare (PWM output)
-
-	patch_register(TIM2_CR1, TIM_CR1_CMS, TIM_CMS_EDGE); // centering mode
-	patch_register(TIM2_CR1, TIM_CR1_DIR, 0); // count upwards only
-
-	// frequency set to 16 kHz
-
-	/*
-	TIM2_PSC = 32; // prescaller
-	TIM2_ARR = 1000; // sets frequency
-	TIM2_CCR2 = 500; // duty cycle
-	*/
-
-	TIM2_PSC = 1; // prescaller
-	TIM2_ARR = 1600; // sets frequency
-	TIM2_CCR2 = 500; // duty cycle
-
-	// generate update event to latch the value registers
-	TIM2_EGR |= TIM_EGR_UG;
-
-	TIM2_CR1 |= TIM_CR1_CEN; // enable timer.
-}
-
-
-
-
-
-
-
-
-
-
-

init.h

@@ -8,4 +8,3 @@ void init_systick(void);
 void init_adc(void);
 void init_dac(void);
 void init_pwm1(void);
-void init_pwm2(void);

main.c

@@ -9,16 +9,6 @@
 
 #include "init.h"
 #include "blink.h"
-#include "capture.h"
-
-// Gate state
-static bool gate_closed = false;
-static uint32_t gate_cnt = 0;
-
-static float exposure_out, exposure_accum;
-static uint32_t exposure_cnt;
-
-static uint32_t pwm2_f = 50;
 
 /** IRQ */
 void USART2_IRQHandler(void)
@@ -34,80 +24,14 @@ void USART2_IRQHandler(void)
 		// handle incoming char.
 		char c = usart_rx_char(USART2);
 		
-		uint32_t pwm2_f_old = pwm2_f;
+		// echo
-
+		usart_tx_char(USART2, c);
-		switch (c) {
-			case 'g': // nulovat pocitadlo preruseni
-				gate_cnt = 0;
-				break;
-
-			case 'm': // zvysit DAC hodnotu
-				if (DAC_DHR12R1 < 4095) DAC_DHR12R1 += 117;
-				break;
-
-			case 'n': // snizit DAC hodnotu
-				if (DAC_DHR12R1 > 0) DAC_DHR12R1 -= 117;
-				break;
-
-			case 'b': // zvysit PWM stridu
-				if (TIM3_CCR1 < 1000) TIM3_CCR1 += 50;
-				break;
-
-			case 'd': // snizit PWM stridu
-				if (TIM3_CCR1 > 0) TIM3_CCR1 -= 50;
-				break;
-
-			case 'f': // zvysit PWM stridu
-				if (pwm2_f < 20000) pwm2_f += 10;
-				break;
-
-			case 's': // snizit PWM stridu
-				if (pwm2_f > 20) pwm2_f -= 10;
-				break;
-
-			case 'F': // zvysit PWM stridu
-				if (pwm2_f < 20000-100) pwm2_f += 100;
-				break;
-
-			case 'S': // snizit PWM stridu
-				if (pwm2_f > 100) {
-					pwm2_f -= 100;
-				} else {
-					pwm2_f = 20;
-				}
-
-				if (pwm2_f < 20) pwm2_f = 20;
-
-				break;
-
-			default:
-				break;
-		}
-
-		if (pwm2_f_old != pwm2_f) {
-			pwm2_set_frequency(pwm2_f);
-		}
 
 		USART2_SR ^= USART_SR_RXNE;
 	}
 }
 
 
-
-// Gate close handler
-void gate_close(void)
-{
-	gate_closed = 1;
-	gate_cnt++;
-}
-
-// Gate open handler
-void gate_open(void)
-{
-	gate_closed = 0;
-}
-
-
 /** Init peripherals; Called by startup script, before main() */
 void SystemInit(void)
 {
@@ -118,82 +42,15 @@ void SystemInit(void)
 	init_adc();
 	init_dac();
 	init_pwm1();
-	init_pwm2();
-
-	pwm2_set_frequency(50);
-
-	register_periodic_task(green_toggle, 1000); // indicate running state
-
-	register_debounced_pin(GPIOB, 11, gate_close, gate_open); // gate handler
 }
 
 
-
 int main(void)
 {
-	char buf[200];
+	usart_tx_string(USART2, "Hello.\n");
-
-	usart_tx_string(USART2, "DAQ system started.\n");
-	delay_ms(100);
 
-	bool first = true;
 	while (1) {
-		float cels = measure_temp();
+		delay_ms(500);
-		float angle = measure_angle();
+		green_toggle();
-		float resis = measure_resistance();
-		float expos = measure_exposure();
-
-		// --- exposure averaging
-		exposure_accum += expos;
-		exposure_cnt++;
-
-		if (exposure_cnt >= 5) {
-			exposure_out = exposure_accum / exposure_cnt;
-			exposure_accum = 0;
-			exposure_cnt = 0;
-		}
-
-		if (first) {
-			exposure_out = expos; // pretend it's averaged
-		}
-		// ---
-
-
-		buf_reset(buf);
-		buf_append_str(buf, "T ");
-		buf_append_flt(buf, cels, 1);
-		buf_append_str(buf, "°C | ");
-
-		buf_append_str(buf, "An ");
-		buf_append_flt(buf, angle, 1);
-		buf_append_str(buf, "° | ");
-
-		buf_append_str(buf, "R ");
-		buf_append_flt(buf, resis, 1);
-		buf_append_str(buf, " | ");
-
-		buf_append_str(buf, "L ");
-		buf_append_flt(buf, exposure_out, 1);
-		buf_append_str(buf, "% | ");
-
-		buf_append_str(buf, "G ");
-		buf_append_str(buf, gate_closed ? "1" : "0");
-		buf_append_str(buf, ", #");
-		buf_append_int(buf, gate_cnt);
-		buf_append_str(buf, " | ");
-
-		buf_append_str(buf, "DA ");
-		buf_append_int(buf, DAC_DHR12R1);
-		buf_append_str(buf, " | ");
-
-		buf_append_str(buf, "PWM ");
-		buf_append_int(buf, TIM3_CCR1);
-
-		buf_append_str(buf, "\n");
-
-		usart_tx_string(USART2, buf);
-
-		delay_ms(100);
-		first = false;
 	}
 }