Merge pull request #70 from ccoenen/patch-1

Readme converted to markdown

Readme.md

@@ -1,4 +1,4 @@
-Readme file for Arduino Time Library
+# Arduino Time Library
 
 Time is a library that provides timekeeping functionality for Arduino.
 
@@ -12,8 +12,11 @@ Example sketches illustrate how similar sketch code can be used with: a Real Tim
 internet NTP time service, GPS time data, and Serial time messages from a computer
 for time synchronization.
 
-The functions available in the library include:
+## Functionality
 
+The functions available in the library include
+
+```c
 hour();            // the hour now  (0-23)
 minute();          // the minute now (0-59)
 second();          // the second now (0-59)
@@ -21,115 +24,132 @@ day();             // the day now (1-31)
 weekday();         // day of the week (1-7), Sunday is day 1
 month();           // the month now (1-12)
 year();            // the full four digit year: (2009, 2010 etc)
+```
 
 there are also functions to return the hour in 12 hour format
+
+```c
 hourFormat12();    // the hour now in 12 hour format
 isAM();            // returns true if time now is AM
 isPM();            // returns true if time now is PM
 
 now();             // returns the current time as seconds since Jan 1 1970
+```
 
 The time and date functions can take an optional parameter for the time. This prevents
 errors if the time rolls over between elements. For example, if a new minute begins
 between getting the minute and second, the values will be inconsistent. Using the
 following functions eliminates this probglem
-  time_t t = now(); // store the current time in time variable t
-  hour(t);          // returns the hour for the given time t
-  minute(t);        // returns the minute for the given time t
-  second(t);        // returns the second for the given time t
-  day(t);           // the day for the given time t
-  weekday(t);       // day of the week for the given time t
-  month(t);         // the month for the given time t
-  year(t);          // the year for the given time t
 
+```c
+time_t t = now(); // store the current time in time variable t
+hour(t);          // returns the hour for the given time t
+minute(t);        // returns the minute for the given time t
+second(t);        // returns the second for the given time t
+day(t);           // the day for the given time t
+weekday(t);       // day of the week for the given time t
+month(t);         // the month for the given time t
+year(t);          // the year for the given time t
+```
 
 Functions for managing the timer services are:
 
-  setTime(t);                      // set the system time to the give time t
+```c
-  setTime(hr,min,sec,day,mnth,yr); // alternative to above, yr is 2 or 4 digit yr
+setTime(t);                      // set the system time to the give time t
-                                   // (2010 or 10 sets year to 2010)
+setTime(hr,min,sec,day,mnth,yr); // alternative to above, yr is 2 or 4 digit yr
-  adjustTime(adjustment);          // adjust system time by adding the adjustment value
+                                 // (2010 or 10 sets year to 2010)
-  timeStatus();                    // indicates if time has been set and recently synchronized
+adjustTime(adjustment);          // adjust system time by adding the adjustment value
-                                   // returns one of the following enumerations:
+timeStatus();                    // indicates if time has been set and recently synchronized
-  timeNotSet                       // the time has never been set, the clock started at Jan 1 1970
+                                 // returns one of the following enumerations:
-  timeNeedsSync                    // the time had been set but a sync attempt did not succeed
+timeNotSet                       // the time has never been set, the clock started at Jan 1 1970
-  timeSet                          // the time is set and is synced
+timeNeedsSync                    // the time had been set but a sync attempt did not succeed
+timeSet                          // the time is set and is synced
+```
 
 Time and Date values are not valid if the status is timeNotSet. Otherwise values can be used but
 the returned time may have drifted if the status is timeNeedsSync. 	
 
-  setSyncProvider(getTimeFunction);  // set the external time provider
+```c
-  setSyncInterval(interval);         // set the number of seconds between re-sync
+setSyncProvider(getTimeFunction);  // set the external time provider
+setSyncInterval(interval);         // set the number of seconds between re-sync
+```
 
-
+There are many convenience macros in the `time.h` file for time constants and conversion
-There are many convenience macros in the time.h file for time constants and conversion
 of time units.
 
 To use the library, copy the download to the Library directory.
 
+## Examples
+
 The Time directory contains the Time library and some example sketches
 illustrating how the library can be used with various time sources:
 
-- TimeSerial.pde shows Arduino as a clock without external hardware.
+- `TimeSerial.pde` shows Arduino as a clock without external hardware.
   It is synchronized by time messages sent over the serial port.
   A companion Processing sketch will automatically provide these messages
   if it is running and connected to the Arduino serial port.
 
-- TimeSerialDateStrings.pde adds day and month name strings to the sketch above
+- `TimeSerialDateStrings.pde` adds day and month name strings to the sketch above
   Short (3 character) and long strings are available to print the days of
   the week and names of the months.
 
-- TimeRTC uses a DS1307 real time clock to provide time synchronization.
+- `TimeRTC` uses a DS1307 real time clock to provide time synchronization.
   A basic RTC library named DS1307RTC is included in the download.
   To run this sketch the DS1307RTC library must be installed.
 
-- TimeRTCSet is similar to the above and adds the ability to set the Real Time Clock
+- `TimeRTCSet` is similar to the above and adds the ability to set the Real Time Clock
 
-- TimeRTCLog demonstrates how to calculate the difference between times.
+- `TimeRTCLog` demonstrates how to calculate the difference between times.
   It is a vary simple logger application that monitors events on digtial pins
   and prints (to the serial port) the time of an event and the time period since
   the previous event.
 
-- TimeNTP uses the Arduino Ethernet shield to access time using the internet NTP time service.
+- `TimeNTP` uses the Arduino Ethernet shield to access time using the internet NTP time service.
   The NTP protocol uses UDP and the UdpBytewise library is required, see:
   http://bitbucket.org/bjoern/arduino_osc/src/14667490521f/libraries/Ethernet/
 
-- TimeGPS gets time from a GPS
+- `TimeGPS` gets time from a GPS
   This requires the TinyGPS library from Mikal Hart:
   http://arduiniana.org/libraries/TinyGPS
 
+## Differences
+
 Differences between this code and the playground DateTime library
 although the Time library is based on the DateTime codebase, the API has changed.
 Changes in the Time library API:
-- time elements are functions returning int (they are variables in DateTime)
+
+- time elements are functions returning `int` (they are variables in DateTime)
 - Years start from 1970
 - days of the week and months start from 1 (they start from 0 in DateTime)
 - DateStrings do not require a seperate library
 - time elements can be accessed non-atomically (in DateTime they are always atomic)
 - function added to automatically sync time with extrnal source
-- localTime and maketime parameters changed, localTime renamed to breakTime
+- `localTime` and `maketime` parameters changed, `localTime` renamed to `breakTime`
 
-Technical notes:
+## Technical notes:
 
-Internal system time is based on the standard Unix time_t.
+Internal system time is based on the standard Unix `time_t`.
 The value is the number of seconds since Jan 1 1970.
 System time begins at zero when the sketch starts.
 
 The internal time can be automatically synchronized at regular intervals to an external time source.
-This is enabled by calling the setSyncProvider(provider) function - the provider argument is
+This is enabled by calling the `setSyncProvider(provider)` function - the provider argument is
-the address of a function that returns the current time as a time_t.
+the address of a function that returns the current time as a `time_t`.
 See the sketches in the examples directory for usage.
 
 The default interval for re-syncing the time is 5 minutes but can be changed by calling the
-setSyncInterval( interval) method to set the number of seconds between re-sync attempts.
+`setSyncInterval(interval)` method to set the number of seconds between re-sync attempts.
 
 The Time library defines a structure for holding time elements that is a compact version of the  C tm structure.
 All the members of the Arduino tm structure are bytes and the year is offset from 1970.
 Convenience macros provide conversion to and from the Arduino format.
 
 Low level functions to convert between system time and individual time elements are provided:
-  breakTime(time, &tm);  // break time_t into elements stored in tm struct
+
-  makeTime(&tm);         // return time_t  from elements stored in tm struct
+```c
+breakTime(time, &tm);  // break time_t into elements stored in tm struct
+makeTime(&tm);         // return time_t  from elements stored in tm struct
+```
 
 The DS1307RTC library included in the download provides an example of how a time provider
 can use the low level functions to interface with the Time library.