wayne roberts
Timeout driver for event at absolute time
Dependents: demo_TimeoutAbs i2c_lora_slave
Timeout driver for generating event at absolute time, i.e. alarm at 12:00PM instead of alarm in 5 minutes.
This is the same concept as TIMER_ABSTIME in clock_nanosleep().
The purpose is to remove dependency on when attach() is called, so the event occurs at correct time regardless of any latency in calling attach().
This driver doesnt add any functionality over mbed-os library; it only skips the call to ticker_read_us() in Ticker::setup(), which just changes a relative time to absolute time.
example use here.
Diff: TimeoutAbs.h
- Revision:
- 0:900163d530ae
- Child:
- 1:ae6b29794806
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/TimeoutAbs.h Mon Nov 26 14:22:55 2018 -0800
@@ -0,0 +1,57 @@
+#include "drivers/TimerEvent.h"
+#include "platform/Callback.h"
+#include "platform/mbed_toolchain.h"
+#include "platform/NonCopyable.h"
+#include "platform/mbed_power_mgmt.h"
+#include "hal/lp_ticker_api.h"
+#include "platform/mbed_critical.h"
+
+namespace mbed {
+
+class TimeoutAbs : public TimerEvent, private NonCopyable<TimeoutAbs> {
+ public:
+ TimeoutAbs() : TimerEvent(), _function(0), _lock_deepsleep(true)
+ {
+ }
+
+ TimeoutAbs(const ticker_data_t* data) : TimerEvent(data), _function(0), _lock_deepsleep(true)
+ {
+#if DEVICE_LPTICKER
+ _lock_deepsleep = (data != get_lp_ticker_data());
+#endif
+ }
+
+ virtual ~TimeoutAbs()
+ {
+ detach();
+ }
+
+ /** Detach the function
+ */
+ void detach();
+
+ void attach_us(Callback<void()> func, us_timestamp_t t)
+ {
+ core_util_critical_section_enter();
+ // lock only for the initial callback setup and this is not low power ticker
+ if (!_function && _lock_deepsleep) {
+ sleep_manager_lock_deep_sleep();
+ }
+ _function = func;
+ abs_setup(t);
+ core_util_critical_section_exit();
+ }
+
+ us_timestamp_t read_us(void)
+ {
+ return ticker_read_us(_ticker_data);
+ }
+
+ protected:
+ void abs_setup(us_timestamp_t);
+ virtual void handler();
+ Callback<void()> _function; /**< Callback. */
+ bool _lock_deepsleep; /**< Flag which indicates if deep sleep should be disabled. */
+};
+
+} // namespace mbed