added basic hard fault handler, moving shit around; debounce made to work

CMakeLists.txt

@@ -1,7 +1,8 @@
 project(f107-fft C ASM)
 cmake_minimum_required(VERSION 3.5.0)
 
-file(GLOB_RECURSE USER_SOURCES "Src/*.c" "Max2719/*.c")
+file(GLOB_RECURSE USER_SOURCES "User/*.c")
+file(GLOB_RECURSE MX_SOURCES "Src/*.c")
 file(GLOB_RECURSE HAL_SOURCES "Drivers/STM32F1xx_HAL_Driver/Src/*.c")
 file(GLOB_RECURSE CMSIS_SOURCES "Drivers/CMSIS/DSP_Lib/Source/*.c")
 
@@ -14,19 +15,21 @@ include_directories(Inc)
 include_directories(Drivers/STM32F1xx_HAL_Driver/Inc)
 include_directories(Drivers/CMSIS/Include)
 include_directories(Drivers/CMSIS/Device/ST/STM32F1xx/Include)
-include_directories(Max2719)
+include_directories(User)
+
+# stdlib path
 include_directories(/usr/arm-none-eabi/include)
 include_directories(/usr/lib/gcc/arm-none-eabi/6.1.1/include/)
 
-
+# defines for the used libraries
 add_definitions(-DSTM32F107xC)
 add_definitions(-DARM_MATH_CM3)
 add_definitions(-DF_CPU=72000000UL)
-
 add_definitions(-DUSE_FULL_ASSERT)
-add_executable(${PROJECT_NAME}.elf ${USER_SOURCES} ${LINKER_SCRIPT})
 
-target_link_libraries(${PROJECT_NAME}.elf HAL CMSIS )
+add_executable(${PROJECT_NAME}.elf ${MX_SOURCES} ${USER_SOURCES} ${LINKER_SCRIPT})
+
+target_link_libraries(${PROJECT_NAME}.elf HAL CMSIS)
 
 set(HEX_FILE ${PROJECT_SOURCE_DIR}/build/${PROJECT_NAME}.hex)
 set(BIN_FILE ${PROJECT_SOURCE_DIR}/build/${PROJECT_NAME}.bin)

Src/gpio.c

@@ -64,13 +64,14 @@ void MX_GPIO_Init(void)
   __HAL_RCC_GPIOD_CLK_ENABLE();
 
   /*Configure GPIO pin Output Level */
-  HAL_GPIO_WritePin(GPIOE, SPI1_CS_Pin|LED4_Pin|LED3_Pin, GPIO_PIN_RESET);
+  HAL_GPIO_WritePin(GPIOE, SPI1_CS_Pin, GPIO_PIN_RESET);
+  HAL_GPIO_WritePin(GPIOE, LED4_Pin|LED3_Pin, 1); // MX: Changed
 
   /*Configure GPIO pin Output Level */
-  HAL_GPIO_WritePin(AUDIO_NSTBY_GPIO_Port, AUDIO_NSTBY_Pin, GPIO_PIN_RESET);
+  HAL_GPIO_WritePin(AUDIO_NSTBY_GPIO_Port, AUDIO_NSTBY_Pin, 1); // MX: Changed
 
   /*Configure GPIO pin Output Level */
-  HAL_GPIO_WritePin(GPIOD, LED2_Pin|LED1_Pin, GPIO_PIN_RESET);
+  HAL_GPIO_WritePin(GPIOD, LED2_Pin|LED1_Pin, 1); // MX: Changed
 
   /*Configure GPIO pins : PEPin PEPin PEPin */
   GPIO_InitStruct.Pin = SPI1_CS_Pin|LED4_Pin|LED3_Pin;
@@ -89,7 +90,7 @@ void MX_GPIO_Init(void)
   GPIO_InitStruct.Pin = BTN_UP_Pin|BTN_DN_Pin|BTN_L_Pin|BTN_R_Pin 
                           |BTN_CE_Pin;
   GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
-  GPIO_InitStruct.Pull = GPIO_NOPULL;
+  GPIO_InitStruct.Pull = GPIO_PULLUP; // MX: Changed
   HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
 
   /*Configure GPIO pins : PDPin PDPin */

Src/stm32f1xx_it.c

@@ -60,13 +60,61 @@ void NMI_Handler(void)
   /* USER CODE END NonMaskableInt_IRQn 1 */
 }
 
+
+/* USER CODE BEGIN prvGetRegistersFromStack */
+/**
+ * Hard Fault diagnosis function (for use with debugger)
+ *
+ * Source:
+ * http://www.freertos.org/Debugging-Hard-Faults-On-Cortex-M-Microcontrollers.html
+ */
+static void __attribute__((noreturn)) __attribute__((used))
+prvGetRegistersFromStack(uint32_t *pulFaultStackAddress)
+{
+	/* These are volatile to try and prevent the compiler/linker optimising them
+	away as the variables never actually get used.  If the debugger won't show the
+	values of the variables, make them global my moving their declaration outside
+	of this function. */
+	volatile __attribute__((unused)) uint32_t r0;
+	volatile __attribute__((unused)) uint32_t r1;
+	volatile __attribute__((unused)) uint32_t r2;
+	volatile __attribute__((unused)) uint32_t r3;
+	volatile __attribute__((unused)) uint32_t r12;
+	volatile __attribute__((unused)) uint32_t lr; /* Link register. */
+	volatile __attribute__((unused)) uint32_t pc; /* Program counter. */
+	volatile __attribute__((unused)) uint32_t psr;/* Program status register. */
+
+	r0 = pulFaultStackAddress[ 0 ];
+	r1 = pulFaultStackAddress[ 1 ];
+	r2 = pulFaultStackAddress[ 2 ];
+	r3 = pulFaultStackAddress[ 3 ];
+
+	r12 = pulFaultStackAddress[ 4 ];
+	lr = pulFaultStackAddress[ 5 ];
+	pc = pulFaultStackAddress[ 6 ];
+	psr = pulFaultStackAddress[ 7 ];
+
+	/* When the following line is hit, the variables contain the register values. */
+	for (;;);
+}
+/* USER CODE END prvGetRegistersFromStack */
+
 /**
 * @brief This function handles Hard fault interrupt.
 */
 void HardFault_Handler(void)
 {
   /* USER CODE BEGIN HardFault_IRQn 0 */
-  uart_print("Hard fault.\n");
+  __asm volatile
+  (
+    " tst lr, #4                                                \n"
+    " ite eq                                                    \n"
+    " mrseq r0, msp                                             \n"
+    " mrsne r0, psp                                             \n"
+    " ldr r1, [r0, #24]                                         \n"
+    " ldr r2, =prvGetRegistersFromStack                         \n"
+    " bx r2                                                     \n"
+  );
 
   /* USER CODE END HardFault_IRQn 0 */
   while (1)
@@ -204,6 +252,5 @@ void DMA1_Channel1_IRQHandler(void)
 }
 
 /* USER CODE BEGIN 1 */
-
 /* USER CODE END 1 */
 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

Src/tim.c

@@ -50,7 +50,7 @@ void MX_TIM3_Init(void)
   htim3.Instance = TIM3;
   htim3.Init.Prescaler = 0;
   htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
-  htim3.Init.Period = 1800*2;
+  htim3.Init.Period = 1800;
   htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
   if (HAL_TIM_OC_Init(&htim3) != HAL_OK)
   {

User/debounce.c

@@ -0,0 +1,176 @@
+#include <stdbool.h>
+#include "debounce.h"
+#include "timebase.h"
+#include "malloc_safe.h"
+
+// ms debounce time
+
+#define DEF_DEBO_TIME 20
+
+typedef struct {
+	GPIO_TypeDef *GPIOx;         ///< GPIO base
+	uint16_t pin;                ///< bit mask
+	bool state;                  ///< current state
+	bool invert;                 ///< invert pin
+	debo_id_t id;                ///< pin ID
+	uint32_t cb_payload;         ///< payload passed to the callbac
+	ms_time_t debo_time;         ///< debouncing time (ms)
+	ms_time_t counter_0;         ///< counter for falling edge (ms)
+	ms_time_t counter_1;         ///< counter for rising edge (ms)
+	void (*falling_cb)(uint32_t);
+	void (*rising_cb)(uint32_t);
+} debo_slot_t;
+
+
+/** Number of allocated slots */
+static size_t debo_slot_count = 0;
+
+/** Slots array */
+static debo_slot_t *debo_slots;
+
+/** Next free pin ID for make_id() */
+static debo_id_t next_pin_id = 1;
+
+void debo_periodic_task(void *unused);
+
+
+/**
+ * @brief Get a valid free pin ID for a new entry.
+ * @return the ID.
+ */
+static debo_id_t make_id(void)
+{
+	debo_id_t id = next_pin_id++;
+
+	// make sure no task is given PID 0
+	if (next_pin_id == DEBO_PIN_NONE) {
+		next_pin_id++;
+	}
+
+	return id;
+}
+
+
+/** Init the debouncer */
+void debounce_init(size_t slot_count)
+{
+	debo_slots = calloc_s(slot_count, sizeof(debo_slot_t));
+	debo_slot_count = slot_count;
+
+	add_periodic_task(debo_periodic_task, NULL, 1, false);
+}
+
+
+/** Register a pin */
+debo_id_t debo_register_pin(debo_init_t *init)
+{
+	for (size_t i = 0; i < debo_slot_count; i++) {
+		debo_slot_t *slot = &debo_slots[i];
+
+		if (slot->id != DEBO_PIN_NONE) continue; // slot is used
+
+		slot->GPIOx = init->GPIOx;
+		slot->pin = init->pin;
+		slot->falling_cb = init->falling_cb;
+		slot->rising_cb = init->rising_cb;
+		slot->cb_payload = init->cb_payload;
+		slot->invert = init->invert;
+		slot->counter_0 = 0;
+		slot->counter_1 = 0;
+		slot->debo_time = (init->debo_time == 0) ? DEF_DEBO_TIME : init->debo_time;
+
+		bool state = HAL_GPIO_ReadPin(slot->GPIOx, slot->pin);
+		if (slot->invert) state = !state;
+		slot->state = state;
+
+		slot->id = make_id();
+
+		return slot->id;
+	}
+
+	return DEBO_PIN_NONE;
+}
+
+
+/** Callback that must be called every 1 ms */
+void debo_periodic_task(void *unused)
+{
+	UNUSED(unused);
+
+	for (size_t i = 0; i < debo_slot_count; i++) {
+		debo_slot_t *slot = &debo_slots[i];
+		if (slot->id == DEBO_PIN_NONE) continue; // unused
+
+		bool state = HAL_GPIO_ReadPin(slot->GPIOx, slot->pin);
+		if (slot->invert) state = !state;
+
+		if (slot->state != state) {
+			if (state == 0) {
+				// falling
+
+				if (slot->counter_0++ == slot->debo_time) {
+					slot->state = 0;
+
+					if (slot->falling_cb != NULL) {
+						slot->falling_cb(slot->cb_payload);
+					}
+				}
+			} else {
+				// rising
+
+				if (slot->counter_1++ == slot->debo_time) {
+					slot->state = 1;
+
+					if (slot->rising_cb != NULL) {
+						slot->rising_cb(slot->cb_payload);
+					}
+				}
+			}
+		} else {
+			// reset counters
+			slot->counter_0 = 0;
+			slot->counter_1 = 0;
+		}
+	}
+}
+
+
+/**
+ * @brief Check if a pin is high
+ * @param pin_id : Slot ID
+ * @return true if the pin is registered and is HIGH
+ */
+bool debo_pin_state(debo_id_t pin_id)
+{
+	if (pin_id == DEBO_PIN_NONE) return false;
+
+	for (size_t i = 0; i < debo_slot_count; i++) {
+		debo_slot_t *slot = &debo_slots[i];
+		if (slot->id != pin_id) continue;
+
+		return slot->state;
+	}
+
+	return false;
+}
+
+
+/**
+ * @brief Remove a pin entry from the debouncer.
+ * @param pin_id : Slot ID
+ * @return true if task found & removed.
+ */
+bool debo_remove_pin(debo_id_t pin_id)
+{
+	if (pin_id == DEBO_PIN_NONE) return false;
+
+	for (size_t i = 0; i < debo_slot_count; i++) {
+		debo_slot_t *slot = &debo_slots[i];
+		if (slot->id != pin_id) continue;
+
+		slot->id = DEBO_PIN_NONE;
+		return true;
+	}
+
+	return false;
+}

User/debounce.h

@@ -0,0 +1,61 @@
+#ifndef MPORK_DEBOUNCE_H
+#define MPORK_DEBOUNCE_H
+
+#include "timebase.h"
+#include "stm32f1xx_hal.h"
+
+// Debouncer requires that you setup SysTick first.
+
+/** Debounced pin ID - used for state readout */
+typedef uint32_t debo_id_t;
+
+/** debo_id_t indicating unused slot */
+#define DEBO_PIN_NONE 0
+
+
+/**
+ * @brief Initialize the debouncer.
+ *
+ * Registers the callback.
+ *
+ * @param pin_count : number of pin slots to allocate
+ */
+void debounce_init(size_t pin_count);
+
+
+typedef struct {
+	GPIO_TypeDef *GPIOx;          ///< GPIO base
+	uint16_t pin;                 ///< pin mask
+	bool invert;                  ///< invert value read from GPIO (button to ground)
+	ms_time_t debo_time;          ///< debounce time in ms, 0 = default (20 ms)
+	uint32_t cb_payload;          ///< Value passed to the callback func
+	void (*rising_cb)(uint32_t);  ///< callback when the pin goes HIGH
+	void (*falling_cb)(uint32_t); ///< callback when the pin goes LOW
+} debo_init_t;
+
+
+/**
+ * @brief Add a pin for debouncing.
+ *
+ * The pin state will be checked with the configured hysteresis
+ * and callbacks will be called when a state change is detected.
+ */
+debo_id_t debo_register_pin(debo_init_t *init_struct);
+
+
+/**
+ * @brief Check if a pin is high
+ * @param pin_id : Slot ID
+ * @return true if the pin is registered and is HIGH
+ */
+bool debo_pin_state(debo_id_t pin_id);
+
+
+/**
+ * @brief Remove a pin entry from the debouncer.
+ * @param pin_id : Slot ID
+ * @return true if task found & removed.
+ */
+bool debo_remove_pin(debo_id_t pin_id);
+
+#endif /* MPORK_DEBOUNCE_H */

User/timebase.c

@@ -0,0 +1,347 @@
+#include "timebase.h"
+#include "malloc_safe.h"
+
+// Time base
+static volatile ms_time_t SystemTime_ms = 0;
+
+
+typedef struct {
+	/** User callback with arg */
+	void (*callback)(void *);
+	/** Arg for the arg callback */
+	void *cb_arg;
+	/** Callback interval */
+	ms_time_t interval_ms;
+	/** Counter, when reaches interval_ms, is cleared and callback is called. */
+	ms_time_t countup;
+	/** Unique task ID (for cancelling / modification) */
+	task_pid_t pid;
+	/** Enable flag - disabled tasks still count, but CB is not run */
+	bool enabled;
+	/** Marks that the task is due to be run */
+	bool enqueue;
+} periodic_task_t;
+
+
+typedef struct {
+	/** User callback with arg */
+	void (*callback)(void *);
+	/** Arg for the arg callback */
+	void *cb_arg;
+	/** Counter, when reaches 0ms, callback is called and the task is removed */
+	ms_time_t countdown_ms;
+	/** Unique task ID (for cancelling / modification) */
+	task_pid_t pid;
+	/** Whether this task is long and needs posting on the queue */
+	bool enqueue;
+} future_task_t;
+
+
+static size_t periodic_slot_count = 0;
+static size_t future_slot_count = 0;
+
+static periodic_task_t *periodic_tasks;
+static future_task_t *future_tasks;
+
+
+/** Init timebase */
+void timebase_init(size_t periodic, size_t future)
+{
+	periodic_slot_count = periodic;
+	future_slot_count = future;
+
+	periodic_tasks = calloc_s(periodic, sizeof(periodic_task_t));
+	future_tasks = calloc_s(future, sizeof(future_task_t));
+}
+
+
+static task_pid_t next_task_pid = 1; // 0 (PID_NONE) is reserved
+
+
+/** Get a valid free PID for a new task. */
+static task_pid_t make_pid(void)
+{
+	task_pid_t pid = next_task_pid++;
+
+	// make sure no task is given PID 0
+	if (next_task_pid == PID_NONE) {
+		next_task_pid++;
+	}
+
+	return pid;
+}
+
+
+/** Take an empty periodic task slot and populate the basics. */
+static periodic_task_t* claim_periodic_task_slot(ms_time_t interval, bool enqueue)
+{
+	for (size_t i = 0; i < periodic_slot_count; i++) {
+		periodic_task_t *task = &periodic_tasks[i];
+		if (task->pid != PID_NONE) continue; // task is used
+
+		task->countup = 0;
+		task->interval_ms = interval - 1;
+		task->enqueue = enqueue;
+		task->pid = make_pid();
+		task->enabled = true;
+		return task;
+	}
+
+	// TODO logging
+	//error("Periodic task table full.");
+
+	return NULL;
+}
+
+
+/** Take an empty future task slot and populate the basics. */
+static future_task_t* claim_future_task_slot(ms_time_t delay, bool enqueue)
+{
+	for (size_t i = 0; i < future_slot_count; i++) {
+		future_task_t *task = &future_tasks[i];
+		if (task->pid != PID_NONE) continue; // task is used
+
+		task->countdown_ms = delay;
+		task->enqueue = enqueue;
+		task->pid = make_pid();
+		return task;
+	}
+
+	//error("Future task table full.");
+
+	return NULL;
+}
+
+/** Add a periodic task with an arg. */
+task_pid_t add_periodic_task(void (*callback)(void*), void* arg, ms_time_t interval, bool enqueue)
+{
+	periodic_task_t *task = claim_periodic_task_slot(interval, enqueue);
+
+	if (task == NULL) return PID_NONE;
+
+	task->callback = callback;
+	task->cb_arg = arg;
+
+	return task->pid;
+}
+
+
+/** Schedule a future task, with uint32_t argument. */
+task_pid_t schedule_task(void (*callback)(void*), void *arg, ms_time_t delay, bool enqueue)
+{
+	future_task_t *task = claim_future_task_slot(delay, enqueue);
+
+	if (task == NULL) return PID_NONE;
+
+	task->callback = callback;
+	task->cb_arg = arg;
+
+	return task->pid;
+}
+
+
+/** Enable or disable a periodic task. */
+bool enable_periodic_task(task_pid_t pid, bool enable)
+{
+	if (pid == PID_NONE) return false;
+
+	for (size_t i = 0; i < periodic_slot_count; i++) {
+		periodic_task_t *task = &periodic_tasks[i];
+		if (task->pid != pid) continue;
+
+		task->enabled = (enable == ENABLE);
+		return true;
+	}
+
+	return false;
+}
+
+
+/** Check if a periodic task is enabled */
+bool is_periodic_task_enabled(task_pid_t pid)
+{
+	if (pid == PID_NONE) return false;
+
+	for (size_t i = 0; i < periodic_slot_count; i++) {
+		periodic_task_t *task = &periodic_tasks[i];
+		if (task->pid != pid) continue;
+
+		return task->enabled;
+	}
+
+	return false;
+}
+
+bool reset_periodic_task(task_pid_t pid)
+{
+	if (pid == PID_NONE) return false;
+
+	for (size_t i = 0; i < periodic_slot_count; i++) {
+		periodic_task_t *task = &periodic_tasks[i];
+		if (task->pid != pid) continue;
+
+		task->countup = 0;
+		return true;
+	}
+
+	return false;
+}
+
+
+bool set_periodic_task_interval(task_pid_t pid, ms_time_t interval)
+{
+	if (pid == PID_NONE) return false;
+
+	for (size_t i = 0; i < periodic_slot_count; i++) {
+		periodic_task_t *task = &periodic_tasks[i];
+		if (task->pid != pid) continue;
+		task->interval_ms = interval;
+		return true;
+	}
+
+	return false;
+}
+
+
+/** Remove a periodic task. */
+bool remove_periodic_task(task_pid_t pid)
+{
+	if (pid == PID_NONE) return false;
+
+	for (size_t i = 0; i < periodic_slot_count; i++) {
+		periodic_task_t *task = &periodic_tasks[i];
+		if (task->pid != pid) continue;
+
+		task->pid = PID_NONE; // mark unused
+		return true;
+	}
+
+	return false;
+}
+
+
+/** Abort a scheduled task. */
+bool abort_scheduled_task(task_pid_t pid)
+{
+	if (pid == PID_NONE) return false;
+
+	for (size_t i = 0; i < future_slot_count; i++) {
+		future_task_t *task = &future_tasks[i];
+		if (task->pid != pid) continue;
+
+		task->pid = PID_NONE; // mark unused
+		return true;
+	}
+
+	return false;
+}
+
+
+/** Run a periodic task */
+static void run_periodic_task(periodic_task_t *task)
+{
+	if (!task->enabled) return;
+
+	if (task->enqueue) {
+		// queued task
+		// FIXME re-implement queue
+		//tq_post(task->callback, task->cb_arg);
+	} else {
+		// immediate task
+		task->callback(task->cb_arg);
+	}
+}
+
+
+/** Run a future task */
+static void run_future_task(future_task_t *task)
+{
+	if (task->enqueue) {
+		// queued task
+		// FIXME re-implement queue
+		//tq_post(task->callback, task->cb_arg);
+	} else {
+		// immediate task
+		task->callback(task->cb_arg);
+	}
+}
+
+
+/**
+ * @brief Millisecond callback, should be run in the SysTick handler.
+ */
+void timebase_ms_cb(void)
+{
+	// increment global time
+	SystemTime_ms++;
+
+	// run periodic tasks
+	for (size_t i = 0; i < periodic_slot_count; i++) {
+		periodic_task_t *task = &periodic_tasks[i];
+		if (task->pid == PID_NONE) continue; // unused
+
+		if (task->countup++ >= task->interval_ms) {
+			// run if enabled
+			run_periodic_task(task);
+			// restart counter
+			task->countup = 0;
+		}
+	}
+
+	// run planned future tasks
+	for (size_t i = 0; i < future_slot_count; i++) {
+		future_task_t *task = &future_tasks[i];
+		if (task->pid == PID_NONE) continue; // unused
+
+		if (task->countdown_ms-- == 0) {
+			// run
+			run_future_task(task);
+			// release the slot
+			task->pid = PID_NONE;
+		}
+	}
+}
+
+
+
+/** Seconds delay */
+void delay_s(uint32_t s)
+{
+	while (s-- != 0) {
+		delay_ms(1000);
+	}
+}
+
+
+/** Delay N ms */
+void delay_ms(ms_time_t ms)
+{
+	ms_time_t start = SystemTime_ms;
+	while ((SystemTime_ms - start) < ms); // overrun solved by unsigned arithmetic
+}
+
+
+/** Get milliseconds elapsed since start timestamp */
+ms_time_t ms_elapsed(ms_time_t start)
+{
+	return SystemTime_ms - start;
+}
+
+
+/** Get current timestamp. */
+ms_time_t ms_now(void)
+{
+	return SystemTime_ms;
+}
+
+
+/** Helper for looping with periodic branches */
+bool ms_loop_elapsed(ms_time_t *start, ms_time_t duration)
+{
+	if (SystemTime_ms - *start >= duration) {
+		*start = SystemTime_ms;
+		return true;
+	}
+
+	return false;
+}

User/timebase.h

@@ -0,0 +1,167 @@
+#ifndef MPORK_TIMEBASE_H
+#define MPORK_TIMEBASE_H
+
+/**
+ * To use the Timebase functionality,
+ * set up SysTick to 1 kHz and call
+ * timebase_ms_cb() in the IRQ.
+ *
+ * If you plan to use pendable future tasks,
+ * also make sure you call run_pending_tasks()
+ * in your main loop.
+ *
+ * This is not needed for non-pendable tasks.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+
+/** Task PID. */
+typedef uint32_t task_pid_t;
+
+/** Time value in ms */
+typedef uint32_t ms_time_t;
+
+// PID value that can be used to indicate no task
+#define PID_NONE 0
+
+/** Loop until timeout - use in place of while() or for(). break and continue work too! */
+#define until_timeout(to_ms) for(uint32_t _utmeo = ms_now(); ms_elapsed(_utmeo) < (to_ms);)
+
+/** Retry a call until a timeout. Variable 'suc' is set to the return value. Must be defined. */
+#define retry_TO(to_ms, call)  \
+	until_timeout(to_ms) { \
+		suc = call; \
+		if (suc) break; \
+	}
+
+/** Init timebase, allocate slots for tasks. */
+void timebase_init(size_t periodic_count, size_t future_count);
+
+/** Must be called every 1 ms */
+void timebase_ms_cb(void);
+
+
+// --- Periodic -----------------------------------------------
+
+
+/**
+ * @brief Add a periodic task with an arg.
+ * @param callback : task callback
+ * @param arg      : callback argument
+ * @param interval : task interval (ms)
+ * @param enqueue  : put on the task queue when due
+ * @return task PID
+ */
+task_pid_t add_periodic_task(void (*callback)(void *), void *arg, ms_time_t interval, bool enqueue);
+
+
+/** Destroy a periodic task. */
+bool remove_periodic_task(task_pid_t pid);
+
+/** Enable or disable a periodic task. Returns true on success. */
+bool enable_periodic_task(task_pid_t pid, bool cmd);
+
+/** Check if a periodic task exists and is enabled. */
+bool is_periodic_task_enabled(task_pid_t pid);
+
+/** Reset timer for a task */
+bool reset_periodic_task(task_pid_t pid);
+
+/** Set inteval */
+bool set_periodic_task_interval(task_pid_t pid, ms_time_t interval);
+
+
+// --- Future -------------------------------------------------
+
+
+/**
+ * @brief Schedule a future task, with uint32_t argument.
+ * @param callback : task callback
+ * @param arg      : callback argument
+ * @param delay    : task delay (ms)
+ * @param enqueue  : put on the task queue when due
+ * @return task PID
+ */
+task_pid_t schedule_task(void (*callback_arg)(void *), void *arg, ms_time_t delay, bool enqueue);
+
+
+/** Abort a scheduled task. */
+bool abort_scheduled_task(task_pid_t pid);
+
+
+// --- Waiting functions --------------------------------------
+
+/** Get milliseconds elapsed since start timestamp */
+ms_time_t ms_elapsed(ms_time_t start);
+
+
+/** Get current timestamp. */
+ms_time_t ms_now(void);
+
+
+/** Delay using SysTick */
+void delay_ms(ms_time_t ms);
+
+
+/** Delay N seconds */
+void delay_s(uint32_t s);
+
+
+inline __attribute__((always_inline))
+void delay_cycles(uint32_t n)
+{
+	uint32_t l = n >> 2;
+
+	__asm volatile(
+		"0: mov r0,r0;"
+		"subs %[count], #1;"
+		"bne 0b;"
+		: [count] "+r"(l)
+	);
+}
+
+
+inline __attribute__((always_inline))
+void delay_ns(uint32_t ns)
+{
+	delay_cycles(ns / 24);
+}
+
+
+/**
+ * @brief Microsecond delay.
+ * @param us
+ */
+inline __attribute__((always_inline))
+void delay_us(uint32_t us)
+{
+	delay_ns(us * 1150);
+}
+
+
+/**
+ * @brief Check if time since `start` elapsed.
+ *
+ * If so, sets the *start variable to the current time.
+ *
+ * Example:
+ *
+ *   ms_time_t s = ms_now();
+ *
+ *   while(1) {
+ *     if (ms_loop_elapsed(&s, 100)) {
+ *       // this is called every 100 ms
+ *     }
+ *     // ... rest of the loop ...
+ *   }
+ *
+ * @param start     start time variable
+ * @param duration  delay length
+ * @return delay elapsed; start was updated.
+ */
+bool ms_loop_elapsed(ms_time_t *start, ms_time_t duration);
+
+#endif /* MPORK_TIMEBASE_H */

User/user_main.c

@@ -3,16 +3,17 @@
 //
 
 #include <inttypes.h>
-#include <stm32f1xx_hal_gpio.h>
-#include <dotmatrix.h>
-#include <arm_math.h>
 #include <arm_const_structs.h>
+#include <arm_math.h>
+#include <stm32f1xx_hal_gpio.h>
+#include "dotmatrix.h"
 #include "mxconstants.h"
 #include "stm32f1xx_hal.h"
 #include "utils.h"
 #include "adc.h"
 #include "tim.h"
 #include "user_main.h"
+#include "debounce.h"
 
 #define SAMPLE_COUNT 256
 #define BIN_COUNT (SAMPLE_COUNT/2)
@@ -20,6 +21,13 @@
 #define SCREEN_W 32
 #define SCREEN_H 16
 
+// Pins
+#define BTN_CENTER 0
+#define BTN_LEFT 1
+#define BTN_RIGHT 2
+#define BTN_UP 3
+#define BTN_DOWN 4
+
 static uint32_t audio_samples[SAMPLE_COUNT * 2]; // 2x size needed for complex FFT
 static float *audio_samples_f = (float *) audio_samples;
 
@@ -30,6 +38,8 @@ static volatile bool capture_pending = false;
 static void display_wave();
 static void display_fft();
 
+// region Audio capture & display
+
 void capture_start()
 {
 	if (capture_pending) return;
@@ -140,20 +150,29 @@ static void display_fft()
 	dmtx_show(dmtx);
 }
 
+// endregion
 
-void user_main()
+// Increment timebase counter each ms
+void HAL_SYSTICK_Callback(void)
 {
-	uart_print("== USER CODE STARTING ==\n");
+	timebase_ms_cb();
+}
 
-	// Leds OFF
+static void gamepad_button_press(uint32_t btn)
-	HAL_GPIO_WritePin(LED1_GPIO_Port, LED1_Pin, 1);
+{
-	HAL_GPIO_WritePin(LED2_GPIO_Port, LED2_Pin, 1);
+	uart_print("Button press ");
-	HAL_GPIO_WritePin(LED3_GPIO_Port, LED3_Pin, 1);
+	char x[2];
-	HAL_GPIO_WritePin(LED4_GPIO_Port, LED4_Pin, 1);
+	x[0] = '0' + btn;
+	x[1] = 0;
+	uart_print(x);
+	uart_print("\n");
+}
 
+void user_init() {
 	// Enable audio input
 	HAL_GPIO_WritePin(AUDIO_NSTBY_GPIO_Port, AUDIO_NSTBY_Pin, 1);
 
+	// Init display
 	DotMatrix_Init disp_init;
 	disp_init.cols = 4;
 	disp_init.rows = 2;
@@ -167,23 +186,60 @@ void user_main()
 	dmtx_clear(disp);
 	dmtx_show(disp);
 
-	uint32_t counter1 = 0;
+	timebase_init(5, 5);
+	debounce_init(5);
+
+	// Gamepad
+	debo_init_t debo;
+	debo.debo_time = 50;
+	debo.invert = true;
+	debo.falling_cb = NULL;
+	debo.rising_cb = gamepad_button_press;
+	// Central button
+	debo.cb_payload = BTN_CENTER;
+	debo.GPIOx = BTN_CE_GPIO_Port;
+	debo.pin = BTN_CE_Pin;
+	debo_register_pin(&debo);
+	// Left
+	debo.cb_payload = BTN_LEFT;
+	debo.GPIOx = BTN_L_GPIO_Port;
+	debo.pin = BTN_L_Pin;
+	debo_register_pin(&debo);
+	// Right
+	debo.cb_payload = BTN_RIGHT;
+	debo.GPIOx = BTN_R_GPIO_Port;
+	debo.pin = BTN_R_Pin;
+	debo_register_pin(&debo);
+	// Up
+	debo.cb_payload = BTN_UP;
+	debo.GPIOx = BTN_UP_GPIO_Port;
+	debo.pin = BTN_UP_Pin;
+	debo_register_pin(&debo);
+	// Down
+	debo.cb_payload = BTN_DOWN;
+	debo.GPIOx = BTN_DN_GPIO_Port;
+	debo.pin = BTN_DN_Pin;
+	debo_register_pin(&debo);
+}
+
+
+void user_main()
+{
+	uart_print("== USER CODE STARTING ==\n");
+
+	user_init();
+
+	ms_time_t counter1 = 0;
 	uint32_t counter2 = 0;
 	while (1) {
-		if (counter1++ == 500) {
+		if (ms_loop_elapsed(&counter1, 500)) {
-			counter2 = 0;
 			// Blink
 			HAL_GPIO_TogglePin(LED1_GPIO_Port, LED1_Pin);
 		}
 
-		if (counter2++ >= 5) {
+		if (!capture_pending) {
-			if (!capture_pending) {
+			capture_start();
-				counter2 = 0;
-				capture_start();
-			}
 		}
-
-		HAL_Delay(1);
 	}
 }