MicroBitButton.h

00001 /*
00002 The MIT License (MIT)
00003 
00004 Copyright (c) 2016 British Broadcasting Corporation.
00005 This software is provided by Lancaster University by arrangement with the BBC.
00006 
00007 Permission is hereby granted, free of charge, to any person obtaining a
00008 copy of this software and associated documentation files (the "Software"),
00009 to deal in the Software without restriction, including without limitation
00010 the rights to use, copy, modify, merge, publish, distribute, sublicense,
00011 and/or sell copies of the Software, and to permit persons to whom the
00012 Software is furnished to do so, subject to the following conditions:
00013 
00014 The above copyright notice and this permission notice shall be included in
00015 all copies or substantial portions of the Software.
00016 
00017 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00018 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00019 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
00020 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00021 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
00022 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
00023 DEALINGS IN THE SOFTWARE.
00024 */
00025 
00026 #ifndef MICROBIT_BUTTON_H
00027 #define MICROBIT_BUTTON_H
00028 
00029 #include "mbed.h"
00030 #include "MicroBitConfig.h"
00031 #include "MicroBitComponent.h"
00032 #include "MicroBitEvent.h"
00033 
00034 #define MICROBIT_PIN_BUTTON_A                   P0_17
00035 #define MICROBIT_PIN_BUTTON_B                   P0_26
00036 #define MICROBIT_PIN_BUTTON_RESET               P0_19
00037 
00038 #define MICROBIT_BUTTON_EVT_DOWN                1
00039 #define MICROBIT_BUTTON_EVT_UP                  2
00040 #define MICROBIT_BUTTON_EVT_CLICK               3
00041 #define MICROBIT_BUTTON_EVT_LONG_CLICK          4
00042 #define MICROBIT_BUTTON_EVT_HOLD                5
00043 #define MICROBIT_BUTTON_EVT_DOUBLE_CLICK        6
00044 
00045 #define MICROBIT_BUTTON_LONG_CLICK_TIME         1000
00046 #define MICROBIT_BUTTON_HOLD_TIME               1500
00047 
00048 #define MICROBIT_BUTTON_STATE                   1
00049 #define MICROBIT_BUTTON_STATE_HOLD_TRIGGERED    2
00050 #define MICROBIT_BUTTON_STATE_CLICK             4
00051 #define MICROBIT_BUTTON_STATE_LONG_CLICK        8
00052 
00053 #define MICROBIT_BUTTON_SIGMA_MIN               0
00054 #define MICROBIT_BUTTON_SIGMA_MAX               12
00055 #define MICROBIT_BUTTON_SIGMA_THRESH_HI         8
00056 #define MICROBIT_BUTTON_SIGMA_THRESH_LO         2
00057 #define MICROBIT_BUTTON_DOUBLE_CLICK_THRESH     50
00058 
00059 enum MicroBitButtonEventConfiguration
00060 {
00061     MICROBIT_BUTTON_SIMPLE_EVENTS,
00062     MICROBIT_BUTTON_ALL_EVENTS
00063 };
00064 
00065 
00066 /**
00067   * Class definition for MicroBit Button.
00068   *
00069   * Represents a single, generic button on the device.
00070   */
00071 class MicroBitButton : public MicroBitComponent
00072 {
00073     PinName name;                                           // mbed pin name for this button.
00074     DigitalIn pin;                                          // The mbed object looking after this pin at any point in time (may change!).
00075 
00076     unsigned long downStartTime;                            // used to store the current system clock when a button down event occurs
00077     uint8_t sigma;                                          // integration of samples over time. We use this for debouncing, and noise tolerance for touch sensing
00078     MicroBitButtonEventConfiguration eventConfiguration;    // Do we want to generate high level event (clicks), or defer this to another service.
00079 
00080     public:
00081 
00082     /**
00083       * Constructor.
00084       *
00085       * Create a software representation of a button.
00086       *
00087       * @param name the physical pin on the processor that should be used as input.
00088       *
00089       * @param id the ID of the new MicroBitButton object.
00090       *
00091       * @param eventConfiguration Configures the events that will be generated by this MicroBitButton instance.
00092       *                           Defaults to MICROBIT_BUTTON_ALL_EVENTS.
00093       *
00094       * @param mode the configuration of internal pullups/pulldowns, as defined in the mbed PinMode class. PullNone by default.
00095       *
00096       * @code
00097       * buttonA(MICROBIT_PIN_BUTTON_A, MICROBIT_ID_BUTTON_A);
00098       * @endcode
00099       */
00100     MicroBitButton(PinName name, uint16_t id, MicroBitButtonEventConfiguration eventConfiguration = MICROBIT_BUTTON_ALL_EVENTS, PinMode mode = PullNone);
00101 
00102     /**
00103       * Tests if this Button is currently pressed.
00104       *
00105       * @code
00106       * if(buttonA.isPressed())
00107       *     display.scroll("Pressed!");
00108       * @endcode
00109       *
00110       * @return 1 if this button is pressed, 0 otherwise.
00111       */
00112     int isPressed();
00113 
00114     /**
00115       * Changes the event configuration used by this button to the given MicroBitButtonEventConfiguration.
00116       *
00117       * All subsequent events generated by this button will then be informed by this configuraiton.
00118       *
00119       * @param config The new configuration for this button. Legal values are MICROBIT_BUTTON_ALL_EVENTS or MICROBIT_BUTTON_SIMPLE_EVENTS.
00120       *
00121       * Example:
00122       * @code
00123       * // Configure a button to generate all possible events.
00124       * buttonA.setEventConfiguration(MICROBIT_BUTTON_ALL_EVENTS);
00125       *
00126       * // Configure a button to suppress MICROBIT_BUTTON_EVT_CLICK and MICROBIT_BUTTON_EVT_LONG_CLICK events.
00127       * buttonA.setEventConfiguration(MICROBIT_BUTTON_SIMPLE_EVENTS);
00128       * @endcode
00129       */
00130     void setEventConfiguration(MicroBitButtonEventConfiguration config);
00131 
00132     /**
00133       * periodic callback from MicroBit system timer.
00134       *
00135       * Check for state change for this button, and fires various events on a state change.
00136       */
00137     virtual void systemTick();
00138 
00139     /**
00140       * Destructor for MicroBitButton, where we deregister this instance from the array of fiber components.
00141       */
00142     ~MicroBitButton();
00143 };
00144 
00145 #endif