car_fmw: implement switching of current car program using push button

car_fmw/src/car_user_btn.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <stdbool.h>
+#include "stm32f4_discovery.h"
+
+typedef void (*user_btn_handler_t)(void);
+static user_btn_handler_t user_btn_handler;
+
+// @handler can be NULL
+inline void user_btn_init(user_btn_handler_t handler)
+{
+    user_btn_handler = handler;
+    STM_EVAL_PBInit(BUTTON_USER, BUTTON_MODE_EXTI);
+}
+
+inline bool user_btn_is_pushed(void)
+{
+    return STM_EVAL_PBGetState(BUTTON_USER) == Bit_SET;
+}
+
+void EXTI0_IRQHandler(void)
+{
+    if (user_btn_handler)
+        user_btn_handler();
+    EXTI_ClearITPendingBit(USER_BUTTON_EXTI_LINE);
+}

car_fmw/src/main.c

@@ -1,5 +1,8 @@
+#include <stddef.h>
+
 #include "car_leds.h"
 #include "car_engine.h"
+#include "car_user_btn.h"
 #include "wait.h"
 
 const uint32_t PROGRAM_DURATION = 0x3FFFFF; 
@@ -58,6 +61,59 @@ static void program_arbitraty_route(void)
     wait(ROUTE_PIECE_DURATION / 2);
 }
 
+typedef void (*car_program_code_t)(void);
+typedef struct car_program_desc {
+    car_program_code_t code;
+    struct {
+        bool green : 1;
+        bool orange : 1;
+        bool red : 1;
+        bool blue : 1;
+    } leds;
+} car_program_desc_t;
+static car_program_desc_t const PROGRAMS[] = {
+    { .code = program_forward, .leds = { .green = 1 } },
+    { .code = program_backward, .leds = { .orange = 1 } },
+    { .code = program_rotation_left, .leds = { .red = 1 } },
+    { .code = program_rotation_right, .leds = { .blue = 1 } },
+    { .code = program_arbitraty_route, .leds = { .green = 1, .orange = 1 } }
+};
+static const size_t PROGRAMS_CNT = sizeof(PROGRAMS) / sizeof(PROGRAMS[0]);
+static size_t cur_program_ix;
+static __IO bool next_program_pending = false;
+
+static void set_cur_program(size_t program_ix)
+{
+    cur_program_ix = program_ix;
+
+    led_set(LED_GREEN, false);
+    led_set(LED_ORANGE, false);
+    led_set(LED_RED, false);
+    led_set(LED_BLUE, false);
+
+    const car_program_desc_t *cpd = &PROGRAMS[cur_program_ix];
+    if (cpd->leds.green)
+        led_set(LED_GREEN, true);
+    if (cpd->leds.orange)
+        led_set(LED_ORANGE, true);
+    if (cpd->leds.red)
+        led_set(LED_RED, true);
+    if (cpd->leds.blue)
+        led_set(LED_BLUE, true);
+}
+
+void proc_next_program_pending(void)
+{
+    if (!next_program_pending)
+        return;
+    next_program_pending = false;
+    set_cur_program((cur_program_ix + 1) % PROGRAMS_CNT);
+}
+
+void set_next_program_pending(void)
+{
+    next_program_pending = true;
+}
 
 int main(void)
 {
@@ -70,8 +126,11 @@ int main(void)
 
     leds_init();
     engine_init();
+    user_btn_init(set_next_program_pending);
+    set_cur_program(0);
 
     while(1) {
-        program_forward();
+        proc_next_program_pending();
+        PROGRAMS[cur_program_ix].code();
     }
 }