feat exmaples: update beep

Signed-off-by: John Sanpe <[email protected]>

Author: pixclk

examples/beep/CMakeLists.txt

@@ -5,7 +5,6 @@
 
 add_executable(beep main.c beep.c)
 target_link_libraries(beep ${CMAKE_PROJECT_NAME})
-target_link_libraries(beep bfdev)
 
 add_custom_command(
     TARGET beep

examples/beep/beep.c

@@ -5,52 +5,69 @@
 #define BEEP_TIMER TIM1
 #define BEEP_CHANNEL TIM_CHANNEL_2
 
+static TIM_HandleTypeDef htim1;
+
 static int
 buzzer_play(unsigned int freq, unsigned int length)
 {
-    TIM_HandleTypeDef TimHandle;
-    TIM_OC_InitTypeDef sConfig;
-    uint32_t period_cycles;
-    uint16_t prescaler, overflow;
-
-    period_cycles = 24000000 / freq;
-    prescaler = period_cycles / 0xffff + 1;
-    overflow = BFDEV_DIV_ROUND_CLOSEST(period_cycles, prescaler);
-
-    TimHandle.Instance = BEEP_TIMER;
-    TimHandle.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
-    TimHandle.Init.CounterMode = TIM_COUNTERMODE_UP;
-    TimHandle.Init.RepetitionCounter = 0;
-    TimHandle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
-    TimHandle.Init.Prescaler = prescaler;
-    TimHandle.Init.Period = overflow;
+    uint32_t prescaler, overflow;
+    uint32_t cycles;
 
-    sConfig.OCMode = TIM_OCMODE_PWM1;
-    sConfig.OCPolarity = TIM_OCPOLARITY_HIGH;
-    sConfig.OCFastMode = TIM_OCFAST_DISABLE;
-    sConfig.OCNPolarity = TIM_OCNPOLARITY_HIGH;
-    sConfig.OCNIdleState = TIM_OCNIDLESTATE_RESET;
-    sConfig.OCIdleState = TIM_OCIDLESTATE_RESET;
-    sConfig.Pulse = overflow >> 1;
+    cycles = 48000000 / freq;
+    overflow = cycles;
+    prescaler = 0;
 
-    if (HAL_TIM_PWM_Init(&TimHandle) != HAL_OK)
-        return -1;
+	while (overflow > UINT16_MAX) {
+        prescaler++;
+		overflow = cycles / (prescaler + 1);
+    }
 
-    if (HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, BEEP_CHANNEL) != HAL_OK)
+    if (prescaler > UINT16_MAX)
         return -1;
 
-    if (HAL_TIM_PWM_Start(&TimHandle, BEEP_CHANNEL) != HAL_OK)
+    __HAL_TIM_SET_PRESCALER(&htim1, prescaler);
+    __HAL_TIM_SET_AUTORELOAD(&htim1, overflow - 1);
+    __HAL_TIM_SET_COMPARE(&htim1, BEEP_CHANNEL, overflow >> 1);
+
+    if (HAL_TIM_PWM_Start(&htim1, BEEP_CHANNEL) != HAL_OK)
         return -1;
 
     HAL_Delay(length);
-    if (HAL_TIM_PWM_Stop(&TimHandle, BEEP_CHANNEL) != HAL_OK)
+    if (HAL_TIM_PWM_Stop(&htim1, BEEP_CHANNEL) != HAL_OK)
+        return -1;
+
+    return 0;
+}
+
+int
+buzzer_init(void)
+{
+    TIM_OC_InitTypeDef sConfig = {};
+
+    htim1.Instance = BEEP_TIMER;
+    htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
+    htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
+    htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
+    htim1.Init.RepetitionCounter = 0;
+
+    sConfig.OCMode = TIM_OCMODE_PWM1;
+    sConfig.OCFastMode = TIM_OCFAST_DISABLE;
+    sConfig.OCPolarity = TIM_OCPOLARITY_HIGH;
+    sConfig.OCIdleState = TIM_OCIDLESTATE_RESET;
+    sConfig.OCNPolarity = TIM_OCNPOLARITY_HIGH;
+    sConfig.OCNIdleState = TIM_OCNIDLESTATE_RESET;
+
+    if (HAL_TIM_PWM_Init(&htim1) != HAL_OK)
+        return -1;
+
+    if (HAL_TIM_PWM_ConfigChannel(&htim1, &sConfig, BEEP_CHANNEL) != HAL_OK)
         return -1;
 
     return 0;
 }
 
 int
-beep(const struct beep_table *table)
+buzzer_beep(const struct beep_table *table)
 {
     unsigned int freq, length;
     int retval;

examples/beep/beep.h

@@ -14,6 +14,9 @@ struct beep_table {
 };
 
 extern int
-beep(const struct beep_table *table);
+buzzer_init(void);
+
+extern int
+buzzer_beep(const struct beep_table *table);
 
 #endif /* _BEEP_H_ */

examples/beep/main.c

@@ -34,7 +34,8 @@ int main(void)
     GPIOInitType.Alternate = GPIO_AF1_TIM1;
     HAL_GPIO_Init(GPIOB, &GPIOInitType);
 
-    beep(mario);
+    buzzer_init();
+    buzzer_beep(mario);
     for (;;);
 
     return 0;