/***************************************************************************/ /* rtc.c */ /* Based on code from Dallas Semiconductor. */ /* Hope is to code for dev board using same pins and then move to our */ /* board. */ /* This code contains functions to use the 3-wire connection, set the */ /* time and alarm for the alarm clock, and check the alarm as well. */ /* Check the main function here for examples of how the final code should */ /* ultimately use the written functions. */ /***************************************************************************/ #include #include //the following two things are needed to write to led for testing #define LED_ADDR 0x21 BYTE xdata Digit[] = {0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92, 0x82, 0xf8, 0x80, 0x98, 0x88, 0x83, 0xc6, 0xa1, 0x86, 0x8e }; // need to set pins that will interface with RTC - DOESN'T WORK WITH EZ-USB SETUP // but the bits correspond to our setup, so keep this in mind. //sbit CE = OUTA ^ 0; //sbit SCLK = OUTA ^ 1; //sbit SDI_IO = OUTA ^ 2; //sbit SDO = OUTB ^ 0; //sbit SERMODE = OUTB ^ 5; /* ----------------------------------------------------------------------- */ // function to reset 3-wire connection void Reset_3W() { //when using 3-wire, must first enable chip while clock is low. OUTA = PINSA & 0xFD; // SCLK = 0; OUTA = PINSA & 0xFE; // CE = 0; OUTA = PINSA | 0x01; // CE = 1; } /* ----------------------------------------------------------------------- */ // function to write data onto 3-wire interface void WBYTE_3W(BYTE W_Byte) { BYTE i; // local variable to count through bits for(i=0; i<8; ++i) { OUTA = PINSA & 0xFB; // SDI_IO = 0; if(W_Byte & 0x01) // if next bit to transfer is 1, set io pin to 1 { OUTA = PINSA | 0x04; // SDI_IO = 1; } //perform rising clock so that device registers input OUTA = PINSA & 0xFD; // SCLK = 0; OUTA = PINSA | 0x02; // SCLK = 1; W_Byte >>= 1; // go to next bit in byte } } /* ----------------------------------------------------------------------- */ // function to read data from 3-wire interface BYTE RBYTE_3W() { BYTE i; // counter through bits BYTE R_Byte; // received byte accumulator BYTE TmpByte; // temporary holder of io pin R_Byte = 0x00; // received byte starts cleared OEA=0xFB; // set sdi pin as input OUTA = PINSA | 0x04; // SDI_IO = 1; for(i=0; i<8; ++i) { // falling edge of clock to change value OUTA = PINSA | 0x02; // SCLK = 1; OUTA = PINSA & 0xFD; // SCLK = 0; TmpByte = (BYTE) (PINSA & 0xFB); // read value from data line TmpByte <<= 5; // move bit to msb of temp R_Byte >>= 1; // move received bits down 1 R_Byte |= TmpByte; // write temp msb into received's msb } OEA=0xFF; // return sdi pin to output return R_Byte; } /* ----------------------------------------------------------------------- */ // this function initializes RTC void Initialize_DS1305() { Reset_3W(); // reset interface //according to Dallas, must clear write protection to initialize RTC //access control register for writing (0x8F) WBYTE_3W(0x8F); WBYTE_3W(0x00); // clear all bits in this register Reset_3W(); // do the same thing again WBYTE_3W(0x8F); WBYTE_3W(0x00); Reset_3W(); // and finally reset again } /* ----------------------------------------------------------------------- */ // this function reads the time from the clock // (and for testing, places second onto LED) void getTime(*BYTE Min, Min10, Hour, Hour10, PM) { BYTE ReadSec; // 4MSB=10s place, 4LSB=1s place for value BYTE ReadMin; // ditto BYTE ReadHour; // ditto //we don't need the rest of the available info for this clock :o) Reset_3W(); // reset 3-wire // need to read seconds register (0x00), so put this onto 3-wire WBYTE_3W(0x00); ReadSec = RBYTE_3W(); // debugging code to write 1s place of second value to LED EZUSB_WriteI2C(LED_ADDR, 0x01, &(Digit[(ReadSec & 0x0f)])); EZUSB_WaitForEEPROMWrite(LED_ADDR); //note that we can now read the next value without specifying its location //since it is next in the RTC memory anyway ReadMin = RBYTE_3W(); ReadHour = RBYTE_3W(); *Min10 = (ReadMin & 0xf0) >> 4; *Min = ReadMin & 0x0f; *Hour10 = (ReadHour & 0x10) >> 4; *Hour = ReadHour & 0x0f; *PM = ReadHour & 0x20; } /* ----------------------------------------------------------------------- */ // this function writes time to the clock given the Sec, Min, and Hour, AM/PM // to input. If setTime=1, time is set. Otherwise, alarm is set. // (Example, if the time setting is for 10:57p, set the values to: // setTime=1, Min=7, Min10=5, Hour=0, Hour10=1, PM=1 void setValue(BYTE setTime, Min, Min10, Hour, Hour10, PM) { BYTE temp = 0; Reset_3W(); // reset 3-wire // what was being set? Time or Alarm? if (setTime) WBYTE_3W(0x80); else WBYTE_3W(0x87); // need to write seconds register, so put this onto 3-wire temp = Min10 << 4; // shift 10s place of minute to 4MSB temp = temp | Min; // and get 1s place of minute, too WBYTE_3W(temp); // because of fast transfer capabilities of RTC, just place hour info onto 3-wire. // remember, bit 8 = type of alarm, bit 7(MSB)=0, bit 6 = 1 for 12-hour time, // bit 5 = 1 if PM, bit 4 = 10s place. For, now I assume we want a daily alarm, // so bit 8 = 0 for all except the final written byte, which gives the "day alarm". temp = 0; temp = 0x40; // set bit 6 for 12-hour if (PM) temp = temp | 0x20; // set bit 5 if time is PM if (Hour10) temp = temp | 0x10; // set bit 4 if time has 10s place temp = temp | Hour; WBYTE_3W(temp); WBYTE_3W(0x80); // day alarm byte } /* ----------------------------------------------------------------------- */ // this function compares the time in RTC to alarm value and returns 1 if // the alarm and current time match. // Keep in mind that we may want to change the system so that an alarm comes // to the microcontroller every minute to update the display. If that is the case, // then we should set Alarm so that the alarm is every minute. // This requires rewriting this code so that the MSB of the seconds byte is 0, // and the other MSB for minutes, seconds, and days is 1. This also means that // comparing the time to an alarm value must be done on the USB. BYTE checkAlarm(BYTE alarmMin, alarmMin10, alarmHour, alarmHour10, alarmPM) { BYTE timeMin; BYTE timeMin10; BYTE timeHour; BYTE timeHour10; BYTE alarmPM; getTime(&timeMin, &timeMin10, &timeHour, &timeHour10, &alarmPM); if ((timeMin == alarmMin) && (timeMin10 == alarmMin10) && (timeHour == alarmHour) && (timeHour10 == alarmHour10) && (timePM == alarmPM)) return 1; else return 0; } /* ----------------------------------------------------------------------- */ void main() { BYTE Min; BYTE Min10; BYTE Hour; BYTE Hour10; BYTE PM; BYTE alarmMin; BYTE alarmMin10; BYTE alarmHour; BYTE alarmHour10; BYTE alarmPM; PORTACFG=0x00; // first set PORTA to i/o //then set PORTA to output.. note that we have to change //pin 2 (i.e., OEA=0xfb) whenever we want to read in a value. OEA=0xff; EZUSB_InitI2C(); // initialize i2c Initialize_DS1305(); // initialize RTC EZUSB_WriteI2C(LED_ADDR, 0x01, &(Digit[1])); // (Sec & 0x0f) EZUSB_WaitForEEPROMWrite(LED_ADDR); while(1) { // if this code is actually working, you should try to make getTime // occur every minute. This can be done by either using an alarm every // minute or doing some type of sleep command. getTime(Min, Min10, Hour, Hour10, PM); // The alarm vs. time match should be done every minute, too. if (checkAlarm(alarmMin, alarmMin10, alarmHour, alarmHour10, alarmPM)) { // check type of alarm // if no alarm, exit // if buzz, play buzz // if mp3, make call to mp3 playing function } // At this point, we should call the LCD function to write the time // to the display. This, too, should be done every minute. // This means you should write Value if you want 1s place // and Value10 if you want 10s place. // If a button is pushed, though, we need to use the I/O Expander's interrupt // and USB's external interrupt capabilities to do the requested function, // like set the time or alarm. // And if a button is pushed to set the time, main code should store // the incoming time value and whether we're setting time or alarm. // Then, call setTime() using the received values. } }