Started implementing the hardware access modules

Nothing tested yet…

Makefile

@@ -136,7 +136,7 @@ program: program_jlink
 reset: reset_jlink
 
 /tmp/jlink_prog_script: Makefile
-	echo "Device STM32F030C8" > $@
+	echo "Device STM32L010K8" > $@
 	echo "connect" >> $@
 	echo "S" >> $@
 	echo "4000" >> $@
@@ -146,7 +146,7 @@ reset: reset_jlink
 	echo "exit" >> $@
 
 /tmp/jlink_rst_script: Makefile
-	echo "Device STM32F030C8" > $@
+	echo "Device STM32L010K8" > $@
 	echo "connect" >> $@
 	echo "S" >> $@
 	echo "4000" >> $@
@@ -177,4 +177,4 @@ program_debug: $(TARGET_BASE).hex
 		-c "shutdown"
 
 debug: $(TARGET_BASE).hex
-	JLinkGDBServerCLExe -device STM32F030K6 -if SWD
+	JLinkGDBServerCLExe -device STM32L010K8 -if SWD

compile_flags.txt

@@ -0,0 +1,30 @@
+-Wall
+-std=c99
+-pedantic
+-Wextra
+-Wimplicit-function-declaration
+-Wredundant-decls
+-Wmissing-prototypes
+-Wstrict-prototypes
+-Wundef
+-Wshadow
+-fno-common
+-ffunction-sections
+-fdata-sections
+-mcpu=cortex-m0
+-mthumb
+-mfloat-abi=soft
+-MD
+-DSTM32L0
+-I./libopencm3/include
+-Ifxplib/include
+-DPOINTPOS=16
+-DVERSION="5aaef38"
+-O0
+-ggdb
+-DDEBUG
+-Wall
+-std=c99
+-pedantic
+-Iinclude
+-DVERSION="0.0.0-896464e"

fxplib

@@ -1 +1 @@
-Subproject commit 896464ee67bbbae82930c9c972e5267b97c7de6d
+Subproject commit 77a69a9ddad11a9f0e780aaad39eff2361b6eca2

src/fan_ctrl_dc.c

@@ -0,0 +1,73 @@
+#include <libopencm3/stm32/gpio.h>
+
+#include "fan_ctrl_dc.h"
+#include "pinout.h"
+
+
+void fan_ctrl_dc_init(void)
+{
+	// configure the GPIOs: DC/DC disabled by default
+	gpio_clear(DCDC_PORT, DCDC_EN_PIN);
+	gpio_mode_setup(DCDC_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, DCDC_EN_PIN);
+
+	// configure the feedback resistor GPIOs. These are used as open-drain
+	// outputs, so either they are configured as input or as output, but the
+	// only valid output value is 0.
+	gpio_clear(DCDC_PORT, DCDC_CTRL_FB0_PIN | DCDC_CTRL_FB1_PIN | DCDC_CTRL_FB2_PIN | DCDC_CTRL_FB3_PIN);
+	gpio_mode_setup(DCDC_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE,
+			DCDC_CTRL_FB0_PIN | DCDC_CTRL_FB1_PIN | DCDC_CTRL_FB2_PIN | DCDC_CTRL_FB3_PIN);
+}
+
+
+void fan_ctrl_dc_enable(void)
+{
+	// enable the DC/DC converter
+	gpio_set(DCDC_PORT, DCDC_EN_PIN);
+}
+
+
+void fan_ctrl_dc_disable(void)
+{
+	// shut down the DC/DC converter and disable all feedback resistors.
+	gpio_clear(DCDC_PORT, DCDC_EN_PIN);
+	gpio_mode_setup(DCDC_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE,
+			DCDC_CTRL_FB0_PIN | DCDC_CTRL_FB1_PIN | DCDC_CTRL_FB2_PIN | DCDC_CTRL_FB3_PIN);
+}
+
+
+void fan_ctrl_dc_set_duty(uint8_t percent)
+{
+	// note: as we only have 4 switchable feedback resistors, there are only 16
+	// voltage steps available.
+
+	uint8_t step = 15 * (uint16_t)percent / 100;
+
+	// if a resistor is active, the output voltage increases. The smallest
+	// resistor (FB0) has the strongest influence on the output voltage.
+	// Therefore, FB0 corresponds to the MSB of the calculated step.
+
+	if(step & (1 << 3)) {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB0_PIN);
+	} else {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB0_PIN);
+	}
+
+	if(step & (1 << 2)) {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB1_PIN);
+	} else {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB1_PIN);
+	}
+
+	if(step & (1 << 1)) {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB2_PIN);
+	} else {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB2_PIN);
+	}
+
+	if(step & (1 << 0)) {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB3_PIN);
+	} else {
+		gpio_mode_setup(DCDC_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, DCDC_CTRL_FB3_PIN);
+	}
+
+}

src/fan_ctrl_dc.h

@@ -0,0 +1,13 @@
+#ifndef FAN_CTRL_DC_H
+#define FAN_CTRL_DC_H
+
+#include <stdint.h>
+
+void fan_ctrl_dc_init(void);
+
+void fan_ctrl_dc_enable(void);
+void fan_ctrl_dc_disable(void);
+
+void fan_ctrl_dc_set_duty(uint8_t percent);
+
+#endif // FAN_CTRL_DC_H

src/fan_ctrl_pwm.c

@@ -0,0 +1,73 @@
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/timer.h>
+
+#include "fan_ctrl_pwm.h"
+
+#include "pinout.h"
+
+void fan_ctrl_pwm_init(void)
+{
+	// disable the DC/DC bypass until PWM control mode is actually enabled
+	gpio_clear(DCDC_PORT, DCDC_BYPASS_SWITCH_PIN);
+	gpio_mode_setup(DCDC_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, DCDC_BYPASS_SWITCH_PIN);
+
+	// *** TIM21 ***
+	// Configure channel 1 for PWM
+	// Ch1 = charge pump output
+
+	timer_set_mode(TIM21, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
+
+	// set up PWM channel
+	timer_set_oc_mode(TIM21, TIM_OC1, TIM_OCM_PWM1);
+	timer_enable_oc_output(TIM21, TIM_OC1);
+	timer_enable_oc_preload(TIM21, TIM_OC1);
+	timer_set_oc_polarity_high(TIM21, TIM_OC1);
+
+	// prescaler
+	timer_set_prescaler(TIM21, 21 - 1); // Timer runs at 100 kHz
+
+	// auto-reload value
+	timer_set_period(TIM21, 100 - 1); // overflow every 100 cycles = 1 kHz
+
+	// output compare value
+	timer_set_oc_value(TIM21, TIM_OC1, 0); // No PWM output by default
+
+	// only generate interrupt on overflow
+	timer_update_on_overflow(TIM21);
+
+	// enable main output
+	timer_enable_break_main_output(TIM21);
+}
+
+
+void fan_ctrl_pwm_enable(void)
+{
+	// enable the DC/DC bypass (power the fan directly from the supply voltage)
+	gpio_set(DCDC_PORT, DCDC_BYPASS_SWITCH_PIN);
+
+	// Enable PWM output on the PWM GPIO
+	gpio_set_af(FAN_PORT, GPIO_AF0, FAN_PWM_PIN);
+
+	// start the PWM timer
+	timer_enable_counter(TIM21);
+}
+
+
+void fan_ctrl_pwm_disable(void)
+{
+	// disable the DC/DC bypass again
+	gpio_clear(DCDC_PORT, DCDC_BYPASS_SWITCH_PIN);
+
+	// set PWM value to 0 and stop the counter
+	timer_set_oc_value(TIM21, TIM_OC1, 0);
+	timer_disable_counter(TIM21);
+
+	// configure the PWM GPIO as input so the fan runs full speed if powered
+}
+
+
+void fan_ctrl_pwm_set_duty(uint8_t percent)
+{
+	// as the timer has 100 steps per cycle, we can directly use the percentage value
+	timer_set_oc_value(TIM21, TIM_OC1, percent);
+}

src/fan_ctrl_pwm.h

@@ -0,0 +1,13 @@
+#ifndef FAN_CTRL_PWM_H
+#define FAN_CTRL_PWM_H
+
+#include <stdint.h>
+
+void fan_ctrl_pwm_init(void);
+
+void fan_ctrl_pwm_enable(void);
+void fan_ctrl_pwm_disable(void);
+
+void fan_ctrl_pwm_set_duty(uint8_t percent);
+
+#endif // FAN_CTRL_PWM_H

src/main.c

@@ -2,6 +2,20 @@
 #include <libopencm3/cm3/systick.h>
 #include <libopencmsis/core_cm3.h>
 
+#include "uart.h"
+#include "fan_ctrl_pwm.h"
+#include "fan_ctrl_dc.h"
+
+static void clock_setup(void)
+{
+	/* We are running on MSI (2.1 MHz) after boot. */
+	rcc_periph_clock_enable(RCC_GPIOA); // for basically everything
+	rcc_periph_clock_enable(RCC_GPIOC); // for UART only
+
+	/* Enable clocks for USART2. */
+	rcc_periph_clock_enable(RCC_USART2);
+}
+
 /* Set up systick to fire freq times per second */
 static void init_systick(int freq)
 {
@@ -19,9 +33,20 @@ int main(void)
 {
 	uint64_t timebase_ms = 0;
 
+	// delay startup a bit to allow debugger to connect before debug pins are
+	// reconfigured to UART.
+	for(uint32_t i = 0; i < 1000000; i++) {
+		__asm__("nop");
+	}
+
+	clock_setup();
 	init_systick(1000);
 
-	//rs485_enqueue("LNSC-2420 v" VERSION " initialized.\n");
+	uart_init();
+	fan_ctrl_pwm_init();
+	fan_ctrl_dc_init();
+
+	uart_enqueue("TinyFanControl v" VERSION " initialized.\n");
 
 	// triggered every 1 ms
 	while (1) {

src/pinout.h

@@ -0,0 +1,36 @@
+#ifndef PINOUT_H
+#define PINOUT_H
+
+/* Fan-related pins */
+
+#define FAN_PORT         GPIOA
+
+#define FAN_PWM_PIN      GPIO2
+#define FAN_TACHO_PIN    GPIO3
+
+/* DC/DC control pins */
+
+#define DCDC_PORT        GPIOA
+
+#define DCDC_EN_PIN                 GPIO8
+
+#define DCDC_CTRL_FB0_PIN           GPIO7
+#define DCDC_CTRL_FB1_PIN           GPIO6
+#define DCDC_CTRL_FB2_PIN           GPIO5
+#define DCDC_CTRL_FB3_PIN           GPIO4
+
+#define DCDC_BYPASS_SWITCH_PIN      GPIO9
+
+/* Analog channels */
+
+#define ANALOG_INPUT_U_NTC          0
+
+/* UART */
+
+#define UART_PORT        GPIOA
+
+#define UART_TX_PIN      GPIO14
+#define UART_RX_PIN      GPIO15
+
+
+#endif // PINOUT_H

src/temp_sensor.c

@@ -0,0 +1,155 @@
+#include <math.h>
+
+#include "temp_sensor.h"
+#include "fxp.h"
+
+#include <libopencm3/cm3/common.h>
+#include <libopencm3/stm32/adc.h>
+#include <libopencm3/stm32/dma.h>
+
+#define ADC_NUM_CHANNELS 2
+static volatile int16_t adc_values[ADC_NUM_CHANNELS];
+
+static fxp_t m_temperature_internal = 0;
+static fxp_t m_temperature_ntc = 0;
+
+/* Temperature sensor calibration value address */
+#define TEMP110_CAL_ADDR ((uint16_t*) ((uint32_t) 0x1FFFF7C2))
+#define TEMP30_CAL_ADDR ((uint16_t*) ((uint32_t) 0x1FFFF7B8))
+#define VDD_CALIB ((int32_t) (330)) /* calibration voltage = 3,30V - DO NOT CHANGE */
+#define VDD_APPLI ((int32_t) (330)) /* actual supply voltage */
+
+/* function for temperature conversion */
+static fxp_t calc_temperature(uint16_t adc_val)
+{
+	int32_t temperature_raw = ((int32_t)adc_val * VDD_APPLI / VDD_CALIB)
+	                          - (int32_t)(*TEMP30_CAL_ADDR);
+
+	fxp_t temperature = FXP_FROM_INT(temperature_raw);
+
+	fxp_t scale_dividend = FXP_FROM_INT(110 - 30);
+	fxp_t scale_divisor = FXP_FROM_INT((int32_t)(*TEMP110_CAL_ADDR - *TEMP30_CAL_ADDR));
+
+	fxp_t scale = fxp_div(scale_dividend, scale_divisor);
+
+	return fxp_add(fxp_mult(temperature, scale), FXP_FROM_INT(30));
+}
+
+
+static fxp_t adc_val_to_pin_voltage(uint16_t adc_val)
+{
+	return fxp_div(
+			fxp_mult(FXP_FROM_INT((int32_t)adc_val), fxp_div(FXP_FROM_INT(33), FXP_FROM_INT(10))),
+			FXP_FROM_INT(4096));
+}
+
+
+static fxp_t calc_temperature_ntc(uint16_t adc_val)
+{
+	static const fxp_t ln_r_ntc_nom = 705030; // ln(47kΩ) converted to fxp_t with 16 fractional bits
+	static const fxp_t r1 = FXP_FROM_INT(10000);
+	static const fxp_t b_constant = FXP_FROM_INT(4125);
+	static const fxp_t ntc_temp_nom = 19539558; // (273.15+25) * 2**16
+	static const fxp_t celsius2kelvin = 17901158; // (273.15) * 2**16
+
+	fxp_t v_r1 = adc_val_to_pin_voltage(adc_val);
+	fxp_t v_ref = fxp_div(FXP_FROM_INT(33), FXP_FROM_INT(10));
+
+	fxp_t r_ntc = fxp_div(fxp_mult(fxp_sub(v_ref, v_r1), r1), v_r1);
+
+	fxp_t ln_r_ntc = fxp_from_float(logf(fxp_to_float(r_ntc)));
+
+	fxp_t temp_k = fxp_div(FXP_FROM_INT(1.0),
+			fxp_div(
+				fxp_add(
+					fxp_div(
+						fxp_sub(
+							ln_r_ntc,
+							ln_r_ntc_nom),
+						b_constant),
+					FXP_FROM_INT(1)),
+				ntc_temp_nom));
+
+	return fxp_sub(temp_k, celsius2kelvin);
+}
+
+
+void temp_sensor_init(void)
+{
+	uint8_t channels[ADC_NUM_CHANNELS] = {
+		0,                    // The NTC is connected to ADC_IN0
+		ADC_CHANNEL_TEMP      // Temperature sensor
+	};
+
+	// Prepare the ADC
+	adc_power_off(ADC1);
+
+	// enable the temperature sensor
+	adc_enable_temperature_sensor();
+
+	// configure ADC
+	//adc_enable_scan_mode(ADC1);
+	//adc_set_clk_source(ADC1, ADC_CLKSOURCE_PCLK_DIV2); // -> 1.05 MHz @ 2.1 MHz ABP
+	ADC_CFGR2(ADC1) = ADC_CFGR2_CKMODE_PCLK_DIV2;
+	adc_set_single_conversion_mode(ADC1);
+	adc_set_resolution(ADC1, ADC_CFGR1_RES_12_BIT);
+	adc_set_sample_time_on_all_channels(ADC1, ADC_SMPR_SMP_12DOT5CYC);
+	//adc_disable_external_trigger_regular(ADC1);
+	adc_set_right_aligned(ADC1);
+	adc_set_regular_sequence(ADC1, ADC_NUM_CHANNELS, channels);
+
+	adc_calibrate(ADC1);
+
+	// configure DMA for ADC
+
+	//nvic_enable_irq(NVIC_DMA1_CHANNEL1_IRQ);
+	//dma_channel_reset(DMA1, DMA_CHANNEL1);
+	dma_set_priority(DMA1, DMA_CHANNEL1, DMA_CCR_PL_LOW);
+	dma_set_memory_size(DMA1, DMA_CHANNEL1, DMA_CCR_MSIZE_16BIT);
+	dma_set_peripheral_size(DMA1, DMA_CHANNEL1, DMA_CCR_PSIZE_16BIT);
+	dma_enable_memory_increment_mode(DMA1, DMA_CHANNEL1);
+	dma_enable_circular_mode(DMA1, DMA_CHANNEL1);
+	dma_set_read_from_peripheral(DMA1, DMA_CHANNEL1);
+	dma_set_peripheral_address(DMA1, DMA_CHANNEL1, (uint32_t) &ADC_DR(ADC1));
+	/* The array adc_values[] is filled with the waveform data to be output */
+	dma_set_memory_address(DMA1, DMA_CHANNEL1, (uint32_t) adc_values);
+	dma_set_number_of_data(DMA1, DMA_CHANNEL1, ADC_NUM_CHANNELS);
+	//dma_enable_transfer_complete_interrupt(DMA1, DMA_CHANNEL1);
+	dma_enable_channel(DMA1, DMA_CHANNEL1);
+
+	adc_enable_dma(ADC1);
+
+	adc_power_on(ADC1);
+}
+
+
+void temp_sensor_trigger_update(void)
+{
+	// start the ADC conversion sequency. The result will be transferred to RAM
+	// by the DMA.
+	adc_start_conversion_regular(ADC1);
+}
+
+
+bool temp_sensor_has_new_values(void)
+{
+	if(dma_get_interrupt_flag(DMA1, DMA_CHANNEL1, DMA_TCIF)) {
+		dma_clear_interrupt_flags(DMA1, DMA_CHANNEL1, DMA_TCIF);
+
+		// TODO: calculate temperature values and cache them here.
+		m_temperature_internal = calc_temperature(adc_values[1]);
+		return true;
+	} else {
+		return false;
+	}
+}
+
+
+fxp_t temp_sensor_get_ntc_temperature(void)
+{
+}
+
+
+fxp_t temp_sensor_get_internal_temperature(void)
+{
+}

src/temp_sensor.h

@@ -0,0 +1,17 @@
+#ifndef TEMP_SENSOR_H
+#define TEMP_SENSOR_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <fxp.h>
+
+void temp_sensor_init(void);
+
+void temp_sensor_trigger_update(void);
+bool temp_sensor_has_new_values(void);
+
+fxp_t temp_sensor_get_ntc_temperature(void);
+fxp_t temp_sensor_get_internal_temperature(void);
+
+#endif // TEMP_SENSOR_H

src/uart.c

@@ -0,0 +1,130 @@
+#include <libopencm3/stm32/usart.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/cm3/nvic.h>
+
+#include "pinout.h"
+
+#include "uart.h"
+
+#define UART_BUFFER_SIZE 128
+static volatile char debugBuffer[UART_BUFFER_SIZE];
+
+static volatile uint16_t readPos, writePos;
+static volatile uint8_t bufferFull, bufferEmpty, usartActive;
+
+void uart_init(void)
+{
+	// initialize the ring buffer
+	readPos = 0;
+	writePos = 0;
+	bufferFull = 0;
+	bufferEmpty = 1;
+	usartActive = 0;
+
+	/* Initialize GPIOs */
+
+	// RX and TX pins
+	gpio_mode_setup(UART_PORT, GPIO_MODE_AF, GPIO_PUPD_NONE, UART_TX_PIN | UART_RX_PIN);
+	gpio_set_af(UART_PORT, GPIO_AF0, UART_TX_PIN | UART_RX_PIN);
+
+	// enable interrupt
+	nvic_enable_irq(NVIC_USART2_IRQ);
+
+	/* Setup USART2 parameters. */
+	usart_set_baudrate(USART2, 115200);
+	usart_set_databits(USART2, 8);
+	usart_set_stopbits(USART2, USART_CR2_STOPBITS_1);
+	usart_set_mode(USART2, USART_MODE_TX);
+	usart_set_parity(USART2, USART_PARITY_NONE);
+	usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
+
+	/* Enable the USART. */
+	usart_enable(USART2);
+
+	/* Enable the USART2 TX Interrupt */
+	usart_enable_tx_interrupt(USART2);
+	usart_enable_tx_complete_interrupt(USART2);
+}
+
+
+static void uart_transfer(void)
+{
+	if(bufferEmpty) {
+		usart_disable_tx_interrupt(USART2);
+		usartActive = 0;
+		return;
+	}
+
+	usart_send(USART2, debugBuffer[readPos]);
+
+	readPos++;
+	if(readPos == UART_BUFFER_SIZE) {
+		readPos = 0;
+	}
+
+	if(readPos == writePos) {
+		bufferEmpty = 1;
+	}
+
+	bufferFull = 0;
+	usart_enable_tx_interrupt(USART2);
+}
+
+
+void usart2_isr(void)
+{
+	if(USART2_ISR & USART_ISR_TXE) {
+		uart_transfer();
+	}
+
+	if(USART2_ISR & USART_ISR_TC) {
+		USART2_ICR |= USART_ICR_TCCF;
+	}
+}
+
+
+void uart_enqueue(const char *str)
+{
+	while(*str) {
+		if(bufferFull) {
+			break;
+		}
+
+		debugBuffer[writePos] = *str;
+
+		writePos++;
+		if(writePos == UART_BUFFER_SIZE) {
+			writePos = 0;
+		}
+
+		if(writePos == readPos) {
+			bufferFull = 1;
+		}
+
+		bufferEmpty = 0;
+
+		str++;
+	}
+
+	if(!usartActive) {
+		usartActive = 1;
+		//gpio_set(UART_PORT, UART_DE_PIN);
+		uart_transfer();
+	}
+}
+
+
+void uart_deepsleep_prepare(void)
+{
+	// force the transceiver to RX mode
+	//gpio_clear(UART_PORT, UART_DE_PIN);
+}
+
+
+void uart_deepsleep_resume(void)
+{
+	// if a transmission is still in progress, switch to TX mode again
+	if(usartActive) {
+		//gpio_set(UART_PORT, UART_DE_PIN);
+	}
+}

src/uart.h

@@ -0,0 +1,11 @@
+#ifndef UART_H
+#define UART_H
+
+void uart_init(void);
+
+void uart_enqueue(const char *str);
+
+void uart_deepsleep_prepare(void);
+void uart_deepsleep_resume(void);
+
+#endif // UART_H