Diff: source/drivers/MicroBitPin.cpp

Revision:

35:8ce23bc1af38

Parent:

1:8aa5cdb4ab67

Child:

36:6837feb07da4

--- a/source/drivers/MicroBitPin.cpp	Wed Jul 13 12:18:13 2016 +0100
+++ b/source/drivers/MicroBitPin.cpp	Wed Jul 13 12:18:14 2016 +0100
@@ -31,6 +31,8 @@
 #include "MicroBitConfig.h"
 #include "MicroBitPin.h"
 #include "MicroBitButton.h"
+#include "MicroBitSystemTimer.h"
+#include "TimedInterruptIn.h"
 #include "DynamicPwm.h"
 #include "ErrorNo.h"
 
@@ -92,8 +94,11 @@
     if (status & IO_STATUS_TOUCH_IN)
         delete ((MicroBitButton *)pin);
 
+    if ((status & IO_STATUS_EVENT_ON_EDGE) || (status & IO_STATUS_EVENT_PULSE_ON_EDGE))
+        delete ((TimedInterruptIn *)pin);
+
     this->pin = NULL;
-    this->status = status & IO_STATUS_EVENTBUS_ENABLED; //retain event bus status
+    this->status = 0;
 }
 
 /**
@@ -135,8 +140,9 @@
 /**
   * Configures this IO pin as a digital input (if necessary) and tests its current value.
   *
+  *
   * @return 1 if this input is high, 0 if input is LO, or MICROBIT_NOT_SUPPORTED
-  *         if the given pin does not have analog capability.
+  *         if the given pin does not have digital capability.
   *
   * @code
   * MicroBitPin P0(MICROBIT_ID_IO_P0, MICROBIT_PIN_P0, PIN_CAPABILITY_BOTH);
@@ -150,12 +156,16 @@
         return MICROBIT_NOT_SUPPORTED;
 
     // Move into a Digital input state if necessary.
-    if (!(status & IO_STATUS_DIGITAL_IN)){
+    if (!(status & (IO_STATUS_DIGITAL_IN | IO_STATUS_EVENT_ON_EDGE | IO_STATUS_EVENT_PULSE_ON_EDGE)))
+    {
         disconnect();
         pin = new DigitalIn(name,PullDown);
         status |= IO_STATUS_DIGITAL_IN;
     }
 
+    if(status & (IO_STATUS_EVENT_ON_EDGE | IO_STATUS_EVENT_PULSE_ON_EDGE))
+        return ((TimedInterruptIn *)pin)->read();
+
     return ((DigitalIn *)pin)->read();
 }
 
@@ -430,3 +440,148 @@
 {
     return getAnalogPeriodUs()/1000;
 }
+
+/**
+  * This member function manages the calculation of the timestamp of a pulse detected
+  * on a pin whilst in IO_STATUS_EVENT_PULSE_ON_EDGE or IO_STATUS_EVENT_ON_EDGE modes.
+  *
+  * @param eventValue the event value to distribute onto the message bus.
+  */
+void MicroBitPin::pulseWidthEvent(int eventValue)
+{
+    MicroBitEvent evt(id, eventValue, CREATE_ONLY);
+    uint64_t now = evt.timestamp;
+    uint64_t previous = ((TimedInterruptIn *)pin)->getTimestamp();
+
+    if (previous != 0)
+    {
+        evt.timestamp -= previous;
+        evt.fire();
+    }
+
+    ((TimedInterruptIn *)pin)->setTimestamp(now);
+}
+
+/**
+  * Interrupt handler for when an rise interrupt is triggered.
+  */
+void MicroBitPin::onRise()
+{
+    if(status & IO_STATUS_EVENT_PULSE_ON_EDGE)
+        pulseWidthEvent(MICROBIT_PIN_EVT_PULSE_LO);
+
+    if(status & IO_STATUS_EVENT_ON_EDGE)
+        MicroBitEvent(id, MICROBIT_PIN_EVT_RISE);
+}
+
+/**
+  * Interrupt handler for when an fall interrupt is triggered.
+  */
+void MicroBitPin::onFall()
+{
+    if(status & IO_STATUS_EVENT_PULSE_ON_EDGE)
+        pulseWidthEvent(MICROBIT_PIN_EVT_PULSE_HI);
+
+    if(status & IO_STATUS_EVENT_ON_EDGE)
+        MicroBitEvent(id, MICROBIT_PIN_EVT_FALL);
+}
+
+/**
+  * This member function will construct an TimedInterruptIn instance, and configure
+  * interrupts for rise and fall.
+  *
+  * @param eventType the specific mode used in interrupt context to determine how an
+  *                  edge/rise is processed.
+  *
+  * @return MICROBIT_OK on success
+  */
+int MicroBitPin::enableRiseFallEvents(int eventType)
+{
+    // if we are in neither of the two modes, configure pin as a TimedInterruptIn.
+    if (!(status & (IO_STATUS_EVENT_ON_EDGE | IO_STATUS_EVENT_PULSE_ON_EDGE)))
+    {
+        disconnect();
+        pin = new TimedInterruptIn(name);
+
+        ((TimedInterruptIn *)pin)->mode(PullDown);
+        ((TimedInterruptIn *)pin)->rise(this, &MicroBitPin::onRise);
+        ((TimedInterruptIn *)pin)->fall(this, &MicroBitPin::onFall);
+    }
+
+    status &= ~(IO_STATUS_EVENT_ON_EDGE | IO_STATUS_EVENT_PULSE_ON_EDGE);
+
+    // set our status bits accordingly.
+    if(eventType == MICROBIT_PIN_EVENT_ON_EDGE)
+        status |= IO_STATUS_EVENT_ON_EDGE;
+    else if(eventType == MICROBIT_PIN_EVENT_ON_PULSE)
+        status |= IO_STATUS_EVENT_PULSE_ON_EDGE;
+
+    return MICROBIT_OK;
+}
+
+/**
+  * If this pin is in a mode where the pin is generating events, it will destruct
+  * the current instance attached to this MicroBitPin instance.
+  *
+  * @return MICROBIT_OK on success.
+  */
+int MicroBitPin::disableEvents()
+{
+    if (status & (IO_STATUS_EVENT_ON_EDGE | IO_STATUS_EVENT_PULSE_ON_EDGE | IO_STATUS_TOUCH_IN))
+        disconnect();
+
+    return MICROBIT_OK;
+}
+
+/**
+  * Configures the events generated by this MicroBitPin instance.
+  *
+  * MICROBIT_PIN_EVENT_ON_EDGE - Configures this pin to a digital input, and generates events whenever a rise/fall is detected on this pin. (MICROBIT_PIN_EVT_RISE, MICROBIT_PIN_EVT_FALL)
+  * MICROBIT_PIN_EVENT_ON_PULSE - Configures this pin to a digital input, and generates events where the timestamp is the duration that this pin was either HI or LO. (MICROBIT_PIN_EVT_PULSE_HI, MICROBIT_PIN_EVT_PULSE_LO)
+  * MICROBIT_PIN_EVENT_ON_TOUCH - Configures this pin as a makey makey style touch sensor, in the form of a MicroBitButton. Normal button events will be generated using the ID of this pin.
+  * MICROBIT_PIN_EVENT_NONE - Disables events for this pin.
+  *
+  * @param eventType One of: MICROBIT_PIN_EVENT_ON_EDGE, MICROBIT_PIN_EVENT_ON_PULSE, MICROBIT_PIN_EVENT_ON_TOUCH, MICROBIT_PIN_EVENT_NONE
+  *
+  * @code
+  * MicroBitMessageBus bus;
+  *
+  * MicroBitPin P0(MICROBIT_ID_IO_P0, MICROBIT_PIN_P0, PIN_CAPABILITY_BOTH);
+  * P0.eventOn(MICROBIT_PIN_EVENT_ON_PULSE);
+  *
+  * void onPulse(MicroBitEvent evt)
+  * {
+  *     int duration = evt.timestamp;
+  * }
+  *
+  * bus.listen(MICROBIT_ID_IO_P0, MICROBIT_PIN_EVT_PULSE_HI, onPulse, MESSAGE_BUS_LISTENER_IMMEDIATE)
+  * @endcode
+  *
+  * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER if the given eventype does not match
+  *
+  * @note In the MICROBIT_PIN_EVENT_ON_PULSE mode, the smallest pulse that was reliably detected was 85us, around 5khz. If more precision is required,
+  *       please use the InterruptIn class supplied by ARM mbed.
+  */
+int MicroBitPin::eventOn(int eventType)
+{
+    switch(eventType)
+    {
+        case MICROBIT_PIN_EVENT_ON_EDGE:
+        case MICROBIT_PIN_EVENT_ON_PULSE:
+            enableRiseFallEvents(eventType);
+            break;
+
+        case MICROBIT_PIN_EVENT_ON_TOUCH:
+            isTouched();
+            break;
+
+        case MICROBIT_PIN_EVENT_NONE:
+            disableEvents();
+            break;
+
+        default:
+            return MICROBIT_INVALID_PARAMETER;
+    }
+
+    return MICROBIT_OK;
+}
\ No newline at end of file