Merge pull request #231 from ubidefeo/master

Added option to initialise lib with custom TwoWire interface

examples/customWire_DS3231onSAMD21/customWire_DS3231onSAMD21.ino

@@ -0,0 +1,120 @@
+/* Using DS3231 (or other supported RTC) with a custom TwoWire instance
+ *
+ * If using a microcontroller which supports additional i2c ports,
+ * such as the SAMD21's SERCOMX, a user can define a custom i2c bus
+ * to use with an RTC.
+ * This example builds the custom i2c bus using SERCOM0 and leverages the "wiring_private.h" APIs
+ * 
+ * Connecting the device:
+ * VCC and GND of RTC should be connected to some power source
+ * SDA, SCL of RTC should be connected to the custom SDA and SCL pins.
+ * In this particular example we are using a Nano 33 IoT and routing 
+ * the custom Wire instance over pins 6 (SDA) and 5 (SCL)
+ *
+ * This example will work with Arduino Zero, any Arduino MKR board based on SAMD21, Nano 33 IoT
+ * and any board by Adafruit, Sparkfun, Seeed Studio based on the same microcontroller
+ * 
+ */
+#include <Wire.h>
+#include "wiring_private.h"
+#include <RTClib.h>
+
+/* Defining the custom TwoWire instance for SAMD21 */
+TwoWire myWire(&sercom0, 6, 5); // Create the new wire instance assigning it to pin 0 and 1
+extern "C"{
+ void SERCOM0_Handler(void);
+
+ void SERCOM0_Handler(void) {
+
+ myWire.onService();
+
+ }
+}
+
+/* Creating a new DS3231 object */
+RTC_DS3231 myRTC;
+
+String daysNames[] = {
+ "Sunday",
+ "Monday",
+ "Tuesday",
+ "Wednesday",
+ "Thursday",
+ "Friday",
+ "Saturday"
+};
+String monthsNames[] = {
+ "-",
+ "January",
+ "February",
+ "March",
+ "April",
+ "May",
+ "June",
+ "July",
+ "August",
+ "September",
+ "October",
+ "November",
+ "December"
+};
+
+void setup() {
+ Serial.begin(57600);
+ Serial.println("start");
+
+ unsigned long setupStartTime = millis();
+ /*** Waiting for Serial to be ready or timeout ***/
+ while(!Serial && millis() - setupStartTime < 3000);
+
+ /* 
+ * Initialising pins 6 and 5 to be routed to the SERCOM0 pads 0 and 1 in order
+ * to be used as SDA and SCL. Without this step the periphearl won't be patched through
+ */ 
+ pinPeripheral(6, PIO_SERCOM_ALT); // PAD[0] //Assign SDA function to pin 0
+ pinPeripheral(5, PIO_SERCOM_ALT); // PAD[1] //Assign SCL function to pin 1
+
+ /* We now pass our custom TwoWire object to the RTC instance */
+ myRTC.begin(&myWire);
+
+ /* 
+ * From this moment on every operation on the RTC will work as expected
+ * But the i2c bus being used will be the one we manually created using SERCOM0
+ */
+
+ /* 
+ * Creating a Date object with 
+ * YEAR, MONTH, DAY (2021, January, 1) 
+ * HOUR, MINUTE, SECONDS (0, 0, 0)
+ * Midnight of January 1st, 2021
+ */
+ DateTime newDT = DateTime(2021, 1, 1, 0, 0, 0);
+
+ /* Pushing that date/time to the RTC */
+ myRTC.adjust(newDT);
+ Serial.println("setup done");
+}
+
+void loop() {
+ /* creating a temporary date/time object to store the data coming from the RTC */
+ DateTime dt = myRTC.now();
+
+ /* printing that data to the Serial port in a meaningful format */ 
+ Serial.println("************");
+ Serial.print(daysNames[dt.dayOfTheWeek()]);
+ Serial.print(" ");
+ Serial.print(monthsNames[dt.month()]);
+ Serial.print(" ");
+ Serial.print(dt.day());
+ Serial.print(", ");
+ Serial.println(dt.year());
+ Serial.print(dt.hour());
+ Serial.print(":");
+ Serial.print(dt.minute());
+ Serial.print(":");
+ Serial.println(dt.second());
+ /* Delays are bad, but let's not flood the Serial for this silly example */
+ delay(500);
+}
+
+

library.properties

@@ -3,7 +3,7 @@ version=1.13.0
 author=Adafruit
 maintainer=Adafruit <[email protected]>
 sentence=A fork of Jeelab's fantastic RTC library
-paragraph=A fork of Jeelab's fantastic RTC library
+paragraph=Works with DS1307, DS3231, PCF8523, PCF8563 on multiple architectures
 category=Timing
 url=https://github.com/adafruit/RTClib
 architectures=*