Revision 5:556829f081f6, committed 2015-05-05

Comitter:

Kojto

Date:

Tue May 05 07:23:40 2015 +0000

Parent:

4:36a163511e34

Commit message:

Support I2C Asynch API

Changed in this revision

diff -r 36a163511e34 -r 556829f081f6 MMA7660.cpp
--- a/MMA7660.cpp	Tue May 13 18:14:34 2014 +0000
+++ b/MMA7660.cpp	Tue May 05 07:23:40 2015 +0000
@@ -1,18 +1,38 @@
 #include "MMA7660.h"
 
-MMA7660::MMA7660(PinName sda, PinName scl, bool active) : _i2c(sda, scl)
+MMA7660::MMA7660(PinName sda, PinName scl, bool active, bool asynch) : _i2c(sda, scl), callback_done(false), asynch(asynch)
 {
+    event.attach(this, &MMA7660::callback);
     setActive(active);
     samplerate = 64;
 }
 
+void MMA7660::callback(int event)
+{
+    if (event == I2C_EVENT_TRANSFER_COMPLETE) {
+        callback_done = true;
+    } else {
+        // handling errors
+    }
+}
+
 //Since the MMA lacks a WHO_AM_I register, we can only check if there is a device that answers to the I2C address
 bool MMA7660::testConnection( void )
 {
-    if (_i2c.write(MMA7660_ADDRESS, NULL, 0) == 0 )
-        return true;
-    else
-        return false;
+    if (!asynch) {
+        if (_i2c.write(MMA7660_ADDRESS, NULL, 0) == 0 )
+            return true;
+        else
+            return false;
+    } else {
+        callback_done = false;
+        char received = 0;
+        _i2c.transfer(MMA7660_ADDRESS, NULL, 0, &received, 1, event, I2C_EVENT_ALL, false);
+        while (!callback_done) {
+            sleep();
+        }
+        return received == 0 ? true : false;
+    }
 }
 
 void MMA7660::setActive(bool state)
@@ -150,21 +170,49 @@
     temp[0]=address;
     temp[1]=data;
 
-    _i2c.write(MMA7660_ADDRESS, temp, 2);
+    if (!asynch) {
+        _i2c.write(MMA7660_ADDRESS, temp, 2);
+    } else {
+        callback_done = false;
+        _i2c.transfer(MMA7660_ADDRESS, &temp[0], 2, NULL, 0, event, I2C_EVENT_ALL);
+        while (!callback_done) {
+            sleep();
+        }
+    }
 }
 
 char MMA7660::read(char address)
 {
-    char retval;
-    _i2c.write(MMA7660_ADDRESS, &address, 1, true);
-    _i2c.read(MMA7660_ADDRESS, &retval, 1);
-    return retval;
+    if (!asynch) {
+        char retval;
+
+        _i2c.write(MMA7660_ADDRESS, &address, 1, true);
+        _i2c.read(MMA7660_ADDRESS, &retval, 1);
+        return retval;
+    } else {
+        callback_done = false;
+        char received = 0;
+        char addr = address;
+        _i2c.transfer(MMA7660_ADDRESS, &addr, 1, &received, 1, event, I2C_EVENT_ALL);
+        while (!callback_done) {
+            sleep();
+        }
+        return received;
+    }
 }
 
 void MMA7660::read(char address, char *data, int length)
 {
-    _i2c.write(MMA7660_ADDRESS, &address, 1, true);
-    _i2c.read(MMA7660_ADDRESS, data, length);
+    if (!asynch) {
+        _i2c.write(MMA7660_ADDRESS, &address, 1, true);
+        _i2c.read(MMA7660_ADDRESS, data, length);
+    } else {
+        callback_done = false;
+        _i2c.transfer(MMA7660_ADDRESS, &address, 1, data, length, event, I2C_EVENT_ALL);
+        while (!callback_done) {
+            sleep();
+        }
+    }
 }
 
 float MMA7660::getSingle( int number )
@@ -191,4 +239,4 @@
         setActive(false);
 
     return temp / MMA7660_SENSITIVITY;
-}
\ No newline at end of file
+}

diff -r 36a163511e34 -r 556829f081f6 MMA7660.h
--- a/MMA7660.h	Tue May 13 18:14:34 2014 +0000
+++ b/MMA7660.h	Tue May 05 07:23:40 2015 +0000
@@ -83,8 +83,9 @@
     * @param sda - I2C data pin
     * @param scl - I2C clock pin
     * @param active - true (default) to enable the device, false to keep it standby
+    * @param asynch - use asynch i2c - the API is blocking which does not break the current app
     */
-    MMA7660(PinName sda, PinName scl, bool active = true);
+    MMA7660(PinName sda, PinName scl, bool active = true, bool asynch = false);
 
     /**
     * Tests if communication is possible with the MMA7660
@@ -168,6 +169,8 @@
 
 private:
 
+    void callback(int event);
+
     /**
     * Writes data to the device
     *
@@ -201,6 +204,9 @@
     I2C _i2c;
     bool active;
     float samplerate;
+    volatile bool callback_done;
+    event_callback_t event;
+    const bool asynch;
 };