MicroBit as BLE gamepad
Dependencies: BLE_API mbed-dev-bin nRF51822
Fork of microbit-dal by
Diff: source/core/MicroBitSystemTimer.cpp
- Revision:
- 35:8ce23bc1af38
- Parent:
- 32:ece16b5987dd
- Child:
- 37:b624ae5e94a5
--- a/source/core/MicroBitSystemTimer.cpp Wed Jul 13 12:18:13 2016 +0100 +++ b/source/core/MicroBitSystemTimer.cpp Wed Jul 13 12:18:14 2016 +0100 @@ -42,18 +42,21 @@ * Time since power on. Measured in milliseconds. * When stored as an unsigned long, this gives us approx 50 days between rollover, which is ample. :-) */ -static unsigned long ticks = 0; +static uint64_t time_us = 0; static unsigned int tick_period = 0; // Array of components which are iterated during a system tick static MicroBitComponent* systemTickComponents[MICROBIT_SYSTEM_COMPONENTS]; // Periodic callback interrupt -static Ticker *timer = NULL; +static Ticker *ticker = NULL; + +// System timer. +static Timer *timer = NULL; /** - * Initialises the system wide timer. + * Initialises a system wide timer, used to drive the various components used in the runtime. * * This must be called before any components register to receive periodic periodic callbacks. * @@ -63,8 +66,14 @@ */ int system_timer_init(int period) { + if (ticker == NULL) + ticker = new Ticker(); + if (timer == NULL) - timer = new Ticker(); + { + timer = new Timer(); + timer->start(); + } return system_timer_set_period(period); } @@ -83,11 +92,11 @@ // If a timer is already running, ensure it is disabled before reconfiguring. if (tick_period) - timer->detach(); + ticker->detach(); // register a period callback to drive the scheduler and any other registered components. tick_period = period; - timer->attach_us(system_timer_tick, period * 1000); + ticker->attach_us(system_timer_tick, period * 1000); return MICROBIT_OK; } @@ -103,13 +112,40 @@ } /** + * Updates the current time in microseconds, since power on. + * + * If the mbed Timer hasn't been initialised, it will be initialised + * on the first call to this function. + */ +void update_time() +{ + // If we haven't been initialized, bring up the timer with the default period. + if (timer == NULL || ticker == NULL) + system_timer_init(SYSTEM_TICK_PERIOD_MS); + + time_us += timer->read_us(); + timer->reset(); +} + +/** * Determines the time since the device was powered on. * * @return the current time since power on in milliseconds */ -unsigned long system_timer_current_time() +uint64_t system_timer_current_time() { - return ticks; + return system_timer_current_time_us() / 1000; +} + +/** + * Determines the time since the device was powered on. + * + * @return the current time since power on in microseconds + */ +uint64_t system_timer_current_time_us() +{ + update_time(); + return time_us; } /** @@ -120,8 +156,7 @@ */ void system_timer_tick() { - // increment our real-time counter. - ticks += system_timer_get_period(); + update_time(); // Update any components registered for a callback for(int i = 0; i < MICROBIT_SYSTEM_COMPONENTS; i++) @@ -144,7 +179,7 @@ int i = 0; // If we haven't been initialized, bring up the timer with the default period. - if (timer == NULL) + if (timer == NULL || ticker == NULL) system_timer_init(SYSTEM_TICK_PERIOD_MS); while(systemTickComponents[i] != NULL && i < MICROBIT_SYSTEM_COMPONENTS)