Warn about low battery before and after moving

Author: Peque

src/hmi.c

@@ -110,6 +110,17 @@ void blink_collision(void)
 	led_right_off();
 }
 
+/**
+ * @brief Warn low battery using speaker sounds.
+ */
+void warn_low_battery(void)
+{
+	speaker_play('C', 4, 0, 0.05);
+	sleep_ticks(50);
+	speaker_play('C', 3, 0, 0.05);
+	sleep_ticks(50);
+}
+
 /**
  * @brief Function to read button left.
  */

src/hmi.h

@@ -5,6 +5,7 @@
 
 #include "clock.h"
 #include "detection.h"
+#include "speaker.h"
 #include "speed.h"
 
 void led_left_toggle(void);
@@ -18,6 +19,7 @@ void led_right_off(void);
 void led_bluepill_off(void);
 void repeat_blink(uint8_t count, uint16_t time);
 void blink_collision(void);
+void warn_low_battery(void);
 bool button_left_read(void);
 bool button_right_read(void);
 bool button_left_read_consecutive(uint32_t count);

src/main.c

@@ -47,6 +47,24 @@ static void user_configuration(bool run)
 	set_speed_mode(mode, run);
 }
 
+/**
+ * @brief Check battery voltage and warn if the voltage is getting too low.
+ */
+static void check_battery_voltage(void)
+{
+	float voltage;
+
+	voltage = get_battery_voltage();
+	if (voltage < 3.6)
+		warn_low_battery();
+	if (voltage < 3.5)
+		warn_low_battery();
+	if (voltage < 3.4)
+		warn_low_battery();
+	if (voltage < 3.3)
+		speaker_play('C', 3, 0, 2.);
+}
+
 /**
  * @brief Includes the functions to be executed before robot starts to move.
  */
@@ -56,6 +74,7 @@ static void before_moving(void)
 	disable_walls_control();
 	repeat_blink(10, 100);
 	sleep_us(5000000);
+	check_battery_voltage();
 	led_left_on();
 	led_right_on();
 	wait_front_sensor_close_signal(0.12);
@@ -79,6 +98,7 @@ static void after_moving(void)
 		repeat_blink(10, 100);
 	}
 	reset_motion();
+	check_battery_voltage();
 }
 
 /**