Diff: source/drivers/MicroBitButton.cpp

Revision:

1:8aa5cdb4ab67

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/drivers/MicroBitButton.cpp	Thu Apr 07 01:33:22 2016 +0100
@@ -0,0 +1,162 @@
+/*
+The MIT License (MIT)
+
+Copyright (c) 2016 British Broadcasting Corporation.
+This software is provided by Lancaster University by arrangement with the BBC.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+*/
+
+#include "MicroBitConfig.h"
+#include "MicroBitButton.h"
+#include "MicroBitSystemTimer.h"
+
+/**
+  * Constructor.
+  *
+  * Create a software representation of a button.
+  *
+  * @param name the physical pin on the processor that should be used as input.
+  *
+  * @param id the ID of the new MicroBitButton object.
+  *
+  * @param eventConfiguration Configures the events that will be generated by this MicroBitButton instance.
+  *                           Defaults to MICROBIT_BUTTON_ALL_EVENTS.
+  *
+  * @param mode the configuration of internal pullups/pulldowns, as defined in the mbed PinMode class. PullNone by default.
+  *
+  * @code
+  * buttonA(MICROBIT_PIN_BUTTON_A, MICROBIT_ID_BUTTON_A);
+  * @endcode
+  */
+MicroBitButton::MicroBitButton(PinName name, uint16_t id, MicroBitButtonEventConfiguration eventConfiguration, PinMode mode) : pin(name, mode)
+{
+    this->id = id;
+    this->name = name;
+    this->eventConfiguration = eventConfiguration;
+    this->downStartTime = 0;
+    this->sigma = 0;
+    system_timer_add_component(this);
+}
+
+/**
+  * Changes the event configuration used by this button to the given MicroBitButtonEventConfiguration.
+  *
+  * All subsequent events generated by this button will then be informed by this configuraiton.
+  *
+  * @param config The new configuration for this button. Legal values are MICROBIT_BUTTON_ALL_EVENTS or MICROBIT_BUTTON_SIMPLE_EVENTS.
+  *
+  * Example:
+  * @code
+  * // Configure a button to generate all possible events.
+  * buttonA.setEventConfiguration(MICROBIT_BUTTON_ALL_EVENTS);
+  *
+  * // Configure a button to suppress MICROBIT_BUTTON_EVT_CLICK and MICROBIT_BUTTON_EVT_LONG_CLICK events.
+  * buttonA.setEventConfiguration(MICROBIT_BUTTON_SIMPLE_EVENTS);
+  * @endcode
+  */
+void MicroBitButton::setEventConfiguration(MicroBitButtonEventConfiguration config)
+{
+    this->eventConfiguration = config;
+}
+
+/**
+  * periodic callback from MicroBit system timer.
+  *
+  * Check for state change for this button, and fires various events on a state change.
+  */
+void MicroBitButton::systemTick()
+{
+    //
+    // If the pin is pulled low (touched), increment our culumative counter.
+    // otherwise, decrement it. We're essentially building a lazy follower here.
+    // This makes the output debounced for buttons, and desensitizes touch sensors
+    // (particularly in environments where there is mains noise!)
+    //
+    if(!pin)
+    {
+        if (sigma < MICROBIT_BUTTON_SIGMA_MAX)
+            sigma++;
+    }
+    else
+    {
+        if (sigma > MICROBIT_BUTTON_SIGMA_MIN)
+            sigma--;
+    }
+
+    // Check to see if we have off->on state change.
+    if(sigma > MICROBIT_BUTTON_SIGMA_THRESH_HI && !(status & MICROBIT_BUTTON_STATE))
+    {
+        // Record we have a state change, and raise an event.
+        status |= MICROBIT_BUTTON_STATE;
+        MicroBitEvent evt(id,MICROBIT_BUTTON_EVT_DOWN);
+
+        //Record the time the button was pressed.
+        downStartTime = system_timer_current_time();
+    }
+
+    // Check to see if we have on->off state change.
+    if(sigma < MICROBIT_BUTTON_SIGMA_THRESH_LO && (status & MICROBIT_BUTTON_STATE))
+    {
+        status = 0;
+        MicroBitEvent evt(id,MICROBIT_BUTTON_EVT_UP);
+
+       if (eventConfiguration == MICROBIT_BUTTON_ALL_EVENTS)
+       {
+           //determine if this is a long click or a normal click and send event
+           if((system_timer_current_time() - downStartTime) >= MICROBIT_BUTTON_LONG_CLICK_TIME)
+               MicroBitEvent evt(id,MICROBIT_BUTTON_EVT_LONG_CLICK);
+           else
+               MicroBitEvent evt(id,MICROBIT_BUTTON_EVT_CLICK);
+       }
+    }
+
+    //if button is pressed and the hold triggered event state is not triggered AND we are greater than the button debounce value
+    if((status & MICROBIT_BUTTON_STATE) && !(status & MICROBIT_BUTTON_STATE_HOLD_TRIGGERED) && (system_timer_current_time() - downStartTime) >= MICROBIT_BUTTON_HOLD_TIME)
+    {
+        //set the hold triggered event flag
+        status |= MICROBIT_BUTTON_STATE_HOLD_TRIGGERED;
+
+        //fire hold event
+        MicroBitEvent evt(id,MICROBIT_BUTTON_EVT_HOLD);
+    }
+}
+
+/**
+  * Tests if this Button is currently pressed.
+  *
+  * @code
+  * if(buttonA.isPressed())
+  *     display.scroll("Pressed!");
+  * @endcode
+  *
+  * @return 1 if this button is pressed, 0 otherwise.
+  */
+int MicroBitButton::isPressed()
+{
+    return status & MICROBIT_BUTTON_STATE ? 1 : 0;
+}
+
+/**
+  * Destructor for MicroBitButton, where we deregister this instance from the array of fiber components.
+  */
+MicroBitButton::~MicroBitButton()
+{
+    system_timer_remove_component(this);
+}