78 lines
2.1 KiB
Plaintext
78 lines
2.1 KiB
Plaintext
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// demo of DS1307 SQW pin output
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#include <I2cMaster.h>
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#include <SoftRTClib.h>
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// constants for SQW test
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uint8_t const SQW_DELAY = 10;
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uint8_t const SQW_INTERRUPT = 0;
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uint8_t const SQW_PIN = 2;
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#if defined(__AVR_ATmega1280__)\
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|| defined(__AVR_ATmega2560__)
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// Mega analog pins 4 and 5
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// pins for DS1307 with software i2c on Mega
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#define SDA_PIN 58
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#define SCL_PIN 59
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#elif defined(__AVR_ATmega168__)\
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||defined(__AVR_ATmega168P__)\
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||defined(__AVR_ATmega328P__)
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// 168 and 328 Arduinos analog pin 4 and 5
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#define SDA_PIN 18
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#define SCL_PIN 19
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#else // CPU type
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#error unknown CPU
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#endif // CPU type
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// An instance of class for software master
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SoftI2cMaster i2c(SDA_PIN, SCL_PIN);
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RTC_DS1307 rtc(&i2c);
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uint32_t sqwCount;
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//------------------------------------------------------------------------------
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void sqwInterrupt(void) {
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sqwCount++;
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}
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//------------------------------------------------------------------------------
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void sqwTest(void) {
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pinMode(SQW_PIN, INPUT);
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// enable pullup
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digitalWrite(SQW_PIN, HIGH);
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Serial.print("Please wait ");
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Serial.print(SQW_DELAY, DEC);
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Serial.println(" seconds.");
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attachInterrupt(SQW_INTERRUPT, sqwInterrupt, FALLING);
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sqwCount = 0;
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delay(SQW_DELAY * 1000UL);
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detachInterrupt(SQW_INTERRUPT);
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Serial.print(sqwCount);
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Serial.print(" interrupts in ");
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Serial.print(SQW_DELAY, DEC);
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Serial.println(" seconds.");
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if (sqwCount == 0) {
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Serial.println("Is SQWE set in the control register?");
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Serial.print("Is SQW connected to pin ");
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Serial.print(SQW_PIN, DEC);
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Serial.println('?');
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}
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}
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//------------------------------------------------------------------------------
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void setup () {
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Serial.begin(9600);
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Serial.print("Connect the DS1307 SQW pin to Arduino pin ");
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Serial.println(SQW_PIN, DEC);
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Serial.println("Type any character to count SQW interrupts");
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while (!Serial.available()) {}
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if (!rtc.setSQW(DS1307_SQW_32768_HZ)) {
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Serial.println("setSqw failed");
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return;
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}
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sqwTest();
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// disable SQW
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rtc.setSQW(DS1307_SQW_LOW);
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}
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//------------------------------------------------------------------------------
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void loop() {}
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