Add Ticker lib (Hardware Timer)

libraries/Ticker/src/Ticker.cpp

@@ -0,0 +1,38 @@
+#include "Ticker.h"
+#include "sysctl.h"
+
+Ticker::Ticker(timer_id_t id)
+:timer_id(id)
+{
+    timer_init(timer_device_number_t(timer_id));
+}
+
+Ticker::~Ticker()
+{
+    detach();
+}
+
+void
+Ticker::_attach_ms(uint32_t milliseconds, bool repeat, callback_with_arg_t callback, size_t arg)
+{
+    user_callback = callback;
+    _arg = arg;
+    timer_set_interval(timer_device_number_t(timer_id), TIMER_CHANNEL_0, milliseconds * 1000000);
+    timer_irq_register(timer_device_number_t(timer_id), TIMER_CHANNEL_0, !repeat, 4, timer_callback, this);
+    timer_set_enable(timer_device_number_t(timer_id), TIMER_CHANNEL_0, 1);
+    sysctl_enable_irq();
+}
+
+void 
+Ticker::detach()
+{
+    timer_irq_unregister(timer_device_number_t(timer_id), TIMER_CHANNEL_0);
+    timer_set_enable(timer_device_number_t(timer_id), TIMER_CHANNEL_0, 0);
+}
+
+static int timer_callback(void* ctx)
+{
+    auto &driver = *reinterpret_cast<Ticker *>(ctx);
+    driver.user_callback((void *)driver._arg);
+    return 0;
+}