Revision 4:42dc07f9ffb3, committed 2013-11-12

Comitter:

neilt6

Date:

Tue Nov 12 17:15:20 2013 +0000

Parent:

3:115e4dacfe07

Child:

5:d67ac8351c76

Commit message:

open() no longer configures the oscillator

Changed in this revision

--- a/ISL1208.cpp	Thu Nov 07 18:21:19 2013 +0000
+++ b/ISL1208.cpp	Tue Nov 12 17:15:20 2013 +0000
@@ -22,19 +22,13 @@
     m_I2C.frequency(400000);
 }
 
-bool ISL1208::open(OscillatorMode mode)
+bool ISL1208::open()
 {
     //Probe for the ISL1208 using a Zero Length Transfer
     if (!m_I2C.write(m_ADDR, NULL, 0)) {
         //Read the current status register
         char sr = read8(REG_CTL_SR);
 
-        //Configure the oscillator mode
-        if (mode == OSCILLATOR_CRYSTAL)
-            sr &= ~(1 << 6);
-        else
-            sr |= (1 << 6);
-
         //Disable auto reset for BAT and ALM bits
         sr &= ~(1 << 7);
 
@@ -171,6 +165,33 @@
     write8(REG_CTL_SR, value);
 }
 
+ISL1208::OscillatorMode ISL1208::oscillatorMode()
+{
+    //Read the 8-bit register value
+    char value = read8(REG_CTL_SR);
+
+    //Return the status of the XTOSCB bit
+    if (value & (1 << 6))
+        return OSCILLATOR_EXTERNAL;
+    else
+        return OSCILLATOR_CRYSTAL;
+}
+
+void ISL1208::oscillatorMode(OscillatorMode mode)
+{
+    //Read the current 8-bit register value
+    char value = read8(REG_CTL_SR);
+
+    //Set or clear the XTOSCB bit
+    if (mode == OSCILLATOR_EXTERNAL)
+        value |= (1 << 6);
+    else
+        value &= ~(1 << 6);
+
+    //Write the value back out
+    write8(REG_CTL_SR, value);
+}
+
 ISL1208::OutputFrequency ISL1208::foutFrequency()
 {
     //Read the 8-bit register value

--- a/ISL1208.h	Thu Nov 07 18:21:19 2013 +0000
+++ b/ISL1208.h	Tue Nov 12 17:15:20 2013 +0000
@@ -32,9 +32,12 @@
  * int main()
  * {
  *     //Try to open the ISL1208
- *     if (rtc.open(ISL1208::OSCILLATOR_CRYSTAL)) {
+ *     if (rtc.open()) {
  *         printf("Device detected!\n");
  *
+ *         //Configure the oscillator for a 32.768kHz crystal
+ *         rtc.oscillatorMode(ISL1208::OSCILLATOR_CRYSTAL);
+ *
  *         //Check if we need to reset the time
  *         if (rtc.powerFailed()) {
  *             //The time has been lost due to a power complete power failure
@@ -138,14 +141,13 @@
      */
     ISL1208(PinName sda, PinName scl);
 
-    /** Probe for the ISL1208 and configures the oscillator mode if present
+    /** Probe for the ISL1208 and configure auto reset if present
      *
-     * @param mode The oscillator mode.
      * @returns
      *   'true' if the device exists on the bus,
      *   'false' if the device doesn't exist on the bus.
      */
-    bool open(OscillatorMode mode);
+    bool open();
 
     /** Get the current time from the ISL1208
      *
@@ -185,6 +187,18 @@
      */
     void clearAlarmFlag();
 
+    /** Get the current oscillator mode of the ISL1208
+     *
+     * @returns The current oscillator mode as a OscillatorMode enum.
+     */
+    ISL1208::OscillatorMode oscillatorMode();
+
+    /** Set the oscillator mode of the ISL1208
+     *
+     * @param mode The new oscillator mode as a OscillatorMode enum.
+     */
+    void oscillatorMode(OscillatorMode mode);
+
     /** Get the current output frequency on the IRQ/fOUT pin
      *
      * @returns The current output frequency.