pbio/battery: Use own process.

This used to be mixed in with the motor process to save a little bit of space, but it is clearer to have the averaging process be inside the battery module.

This will allow us to stop the motor process on shutdown without stopping the battery process.

Author: laurensvalk

lib/pbio/include/pbio/battery.h

@@ -27,8 +27,7 @@
 #if PBIO_CONFIG_BATTERY
 
 /** @cond INTERNAL */
-pbio_error_t pbio_battery_init(void);
-pbio_error_t pbio_battery_update(void);
+void pbio_battery_init(void);
 /** @endcond */
 int32_t pbio_battery_get_average_voltage(void);
 int32_t pbio_battery_get_duty_from_voltage(int32_t voltage);
@@ -37,12 +36,7 @@ int32_t pbio_battery_get_voltage_from_duty_pct(int32_t duty);
 
 #else // PBIO_CONFIG_BATTERY
 
-static inline pbio_error_t pbio_battery_init(void) {
-    return PBIO_ERROR_NOT_SUPPORTED;
-}
-
-static inline pbio_error_t pbio_battery_update(void) {
-    return PBIO_ERROR_NOT_SUPPORTED;
+static inline void pbio_battery_init(void) {
 }
 
 static inline int32_t pbio_battery_get_average_voltage(void) {

lib/pbio/src/battery.c

@@ -13,10 +13,7 @@
 #include <pbdrv/battery.h>
 #include <pbio/battery.h>
 #include <pbio/int_math.h>
-
-#if !PBIO_CONFIG_MOTOR_PROCESS
-#error "PBIO_CONFIG_MOTOR_PROCESS must be enabled to continously update battery voltage."
-#endif
+#include <pbio/os.h>
 
 // Slow moving average battery voltage.
 static int32_t battery_voltage_avg_scaled;
@@ -25,46 +22,6 @@ static int32_t battery_voltage_avg_scaled;
 // to reduce rounding errors in the moving average.
 #define SCALE (1024)
 
-/**
- * Initializes battery voltage state to first measurement.
- *
- * @return                  Error code.
- */
-pbio_error_t pbio_battery_init(void) {
-
-    // Get battery voltage.
-    uint16_t battery_voltage_now_mv;
-    pbio_error_t err = pbdrv_battery_get_voltage_now(&battery_voltage_now_mv);
-    if (err != PBIO_SUCCESS) {
-        return err;
-    }
-
-    // Initialize average voltage.
-    battery_voltage_avg_scaled = (int32_t)battery_voltage_now_mv * SCALE;
-
-    return PBIO_SUCCESS;
-}
-
-/**
- * Updates the average voltage using a new measurement.
- *
- * @return                  Error code.
- */
-pbio_error_t pbio_battery_update(void) {
-
-    // Get battery voltage.
-    uint16_t battery_voltage_now_mv;
-    pbio_error_t err = pbdrv_battery_get_voltage_now(&battery_voltage_now_mv);
-    if (err != PBIO_SUCCESS) {
-        return err;
-    }
-
-    // Update moving average.
-    battery_voltage_avg_scaled = (battery_voltage_avg_scaled * 127 + ((int32_t)battery_voltage_now_mv) * SCALE) / 128;
-
-    return PBIO_SUCCESS;
-}
-
 /**
  * Gets the moving average battery voltage.
  *
@@ -116,4 +73,46 @@ int32_t pbio_battery_get_voltage_from_duty_pct(int32_t duty) {
     return duty * (battery_voltage_avg_scaled / SCALE) / 100;
 }
 
+static pbio_os_process_t pbio_battery_process;
+
+static pbio_error_t pbio_battery_process_thread(pbio_os_state_t *state, void *context) {
+
+    static pbio_os_timer_t timer;
+
+    PBIO_OS_ASYNC_BEGIN(state);
+
+    pbio_os_timer_set(&timer, PBIO_CONFIG_CONTROL_LOOP_TIME_MS);
+
+    for (;;) {
+        uint16_t battery_voltage_now_mv;
+        pbdrv_battery_get_voltage_now(&battery_voltage_now_mv);
+        // Returned error is ignored.
+
+        // Update moving average.
+        battery_voltage_avg_scaled = (battery_voltage_avg_scaled * 127 + ((int32_t)battery_voltage_now_mv) * SCALE) / 128;
+
+        pbio_os_timer_extend(&timer);
+        PBIO_OS_AWAIT_UNTIL(state, pbio_os_timer_is_expired(&timer));
+    }
+
+    // Unreachable.
+    PBIO_OS_ASYNC_END(PBIO_ERROR_FAILED);
+}
+
+/**
+ * Initializes battery voltage state to first measurement.
+ */
+void pbio_battery_init(void) {
+
+    // Get battery voltage.
+    uint16_t battery_voltage_now_mv;
+    pbdrv_battery_get_voltage_now(&battery_voltage_now_mv);
+    // Returned error is ignored.
+
+    // Initialize average upscaled voltage.
+    battery_voltage_avg_scaled = (int32_t)battery_voltage_now_mv * SCALE;
+
+    pbio_os_process_start(&pbio_battery_process, pbio_battery_process_thread, NULL);
+}
+
 #endif // PBIO_CONFIG_BATTERY

lib/pbio/src/main.c

@@ -10,6 +10,7 @@
 
 #include <pbdrv/sound.h>
 
+#include <pbio/battery.h>
 #include <pbio/imu.h>
 #include <pbio/motor_process.h>
 #include <pbio/port_interface.h>
@@ -27,6 +28,7 @@
  */
 void pbio_init(bool start_processes) {
 
+    pbio_battery_init();
     pbio_imu_init();
 
     if (!start_processes) {

lib/pbio/src/motor_process.c

@@ -3,7 +3,6 @@
 
 #include <pbdrv/clock.h>
 
-#include <pbio/battery.h>
 #include <pbio/control.h>
 #include <pbio/drivebase.h>
 #include <pbio/servo.h>
@@ -23,13 +22,7 @@ static pbio_error_t pbio_motor_process_thread(pbio_os_state_t *state, void *cont
     timer.start = pbdrv_clock_get_ms() - PBIO_CONFIG_CONTROL_LOOP_TIME_MS;
     timer.duration = PBIO_CONFIG_CONTROL_LOOP_TIME_MS;
 
-    // Initialize battery voltage.
-    pbio_battery_init();
-
     for (;;) {
-        // Update battery voltage.
-        pbio_battery_update();
-
         // Update drivebase
         pbio_drivebase_update_all();