'------------------------------------------------------------------ ' DS1307 Library for PIC18 Basic ' BY COS, 2026/03/21, 2024/10, Pic18 Oshonsoft v5.68 ' Description: This library handles communication with the ' DS1307 Real-Time Clock (RTC) module using PIC18. ' It contains functions for writing, reading, and ' configuring the clock. '------------------------------------------------------------------- ' Pin definition for I2C communication with the DS1307 'DS1307_SDA = TRISC.4 'DS1307_SCL = TRISC.3 ' I2C protocol constants 'Const ACK = 0 ' Acknowledge (confirmation) 'Const NACK = 1 ' No Acknowledge (no confirmation) ' I2C address of the DS1307 (0xD0 is the base address). Const DS1307_ADDRESS = 0xD0 '--------------------------------------------------------------- ' Proc: DS1307_Init ' Description: Inicializa el módulo DS1307, verifica y reinicia el oscilador. ' Arguments: Ninguno. ' Returns: Ninguno. '--------------------------------------------------------------- Proc DS1307_Init() ' Verifica si el oscilador está detenido. Dim seconds As Byte seconds = DS1307_Read(0x00) ' Lee el registro de segundos. If seconds & 0x80 Then ' Si el bit 7 está en 1, el oscilador está detenido. Call DS1307_Write(0x00, seconds & 0x7f) ' Reinicia el oscilador si está detenido. Endif WaitMs 10 End Proc '--------------------------------------------------------------- ' Proc: DS1307_Set_24h ' Descripción: Configura el DS1307 en modo de 24 horas. ' Argumentos: Ninguno. ' Retorna: Ninguno. '--------------------------------------------------------------- Proc DS1307_Set_24h() Dim hour_register As Byte Dim hour As Byte hour_register = DS1307_Read(0x02) ' Lee el registro de hora actual. hour = hour_register 'Variable temporal para la hora. 'Borra los bits de control. En el DS1307, el bit 6 es el indicador de modo 12/24 horas. hour.6 = 0 'Modo 24 horas. hour = Get_BcdToDEC(hour) 'Convierte la hora de BCD a decimal. If hour_register.6 = 1 Then 'Si está en modo 12 horas If hour_register.5 = 1 Then 'Si es PM If hour < 12 Then hour = hour + 12 'Convierte la hora de 12h a 24h. Else If hour = 12 Then hour = 0 '0h (24h). Endif Call DS1307_Write(0x02, Get_DecToBCD(hour)) 'Convierte la hora de decimal a BCD y actualiza el DS1307. Endif End Proc '--------------------------------------------------------------- ' Proc: DS1307_Set_12h ' Descripción: Configura el DS1307 en modo de 12 horas. ' Argumentos: Ninguno. ' Retorna: Ninguno. '--------------------------------------------------------------- Proc DS1307_Set_12h() Dim hour_register As Byte Dim hour As Byte hour_register = DS1307_Read(0x02) ' Lee el registro de hora actual. hour = hour_register hour = Get_BcdToDEC(hour_register) 'Convierte el registro de hora de BCD a decimal. hour.6 = 0 'Modo de 24 horas (bit 6 del DS1307). hour.5 = 0 'Borra el bit de AM/PM en modo de 12h o el bit más significativo en 24h. 'De 24h a 12h, si ya está en modo de 12h no hace nada. If hour_register.6 = 0 Then 'Modo de 24 horas If hour >= 12 Then 'Si la hora está entre 12h (PM) y 23h. 'Convertir a modo de 12h PM. 'Si la hora = 12, no se modifica. If hour > 12 Then hour = hour - 12 'A 12h hour = Get_DecToBCD(hour) 'Convierte la hora de decimal a BCD. hour.6 = 1 'Inserta el bit que indica el modo de 12 horas (bit 6). hour.5 = 1 'Asigna el modo PM. Call DS1307_Write(0x02, hour) 'Escribe el registro de hora. Else If hour = 0 Then hour = 12 '00h a 12h AM hour = Get_DecToBCD(hour) 'Convierte la hora de decimal a BCD. hour.6 = 1 'Inserta el bit que indica el modo de 12 horas (bit 6). hour.5 = 0 'Modo AM. Call DS1307_Write(0x02, hour) 'Actualiza el registro de hora. Endif Endif End Proc '--------------------------------------------------------------- ' Proc: DS1307_Set_AM_PM ' Description: Configures the DS1307 in AM/PM mode. ' Arguments: mode (short) - 0 for AM, 1 for PM. ' Returns: None '--------------------------------------------------------------- Const AM_ON = 0 'AM Const AM_OFF = 1 'PM Const PM_ON = 1 'PM Const PM_OFF = 0 'AM Proc DS1307_Set_AM_PM(mode As Short) Dim hour_register As Byte Call DS1307_Set_12h() ' Switch to 12-hour mode hour_register = DS1307_Read(0x02) ' Read the current hour register hour_register.5 = mode.0 ' Set the AM/PM bit Call DS1307_Write(0x02, hour_register) ' Write the updated hour register End Proc '--------------------------------------------------------------- ' Function: DS1307_Get_AM_PM_24h ' Description: Retrieves the AM/PM/24-hour mode from the DS1307. ' Arguments: None ' Returns: A Short integer (-1 for 24-hour mode, 0 for AM, 1 for PM) '--------------------------------------------------------------- Function DS1307_Get_AM_PM_24h() As Short Dim hour_register As Byte Dim AmPm24h As Short AmPm24h = -1 ' Default to 24-hour mode hour_register = DS1307_Read(0x02) ' Read the current hour register If hour_register.6 = 1 Then ' Check if the DS1307 is in 12-hour mode If hour_register.5 = 0 Then ' If bit 5 is 0, it's AM AmPm24h = 0 ' Return AM Else AmPm24h = 1 ' Return PM Endif Endif ReturnValue AmPm24h ' Return the current mode (AM/PM/24h) End Function '--------------------------------------------------------------- ' Proc: DS1307_Write ' Description: Sends a command and a data byte to the DS1307. ' Arguments: address (Byte) - The address of the register. ' data (Byte) - The data to be written. ' Returns: None '--------------------------------------------------------------- Proc DS1307_Write(address As Byte, data As Byte) Start_I2C() ' Start I2C communication Write_I2C(DS1307_ADDRESS) ' DS1307 I2C write address Write_I2C(address) ' Write register address Write_I2C(data) ' Write the data to the register Stop_I2C() ' End I2C communication End Proc '--------------------------------------------------------------- ' Function: DS1307_Read ' Description: Reads a byte from the DS1307. ' Arguments: address (Byte) - The address of the register to read from. ' Returns: A Byte of data read from the DS1307. '--------------------------------------------------------------- Function DS1307_Read(address As Byte) As Byte Dim data As Byte Start_I2C() ' Start I2C communication Write_I2C(DS1307_ADDRESS) ' DS1307 I2C write address Write_I2C(address) ' Send the register address to read from Start_I2C() ' Repeated start for reading Write_I2C(DS1307_ADDRESS +1) ' DS1307 I2C Read address data = Read_I2C(NACK) ' Read the data from the DS1307 Stop_I2C() ' End I2C communication ReturnValue data ' Return the read data End Function '--------------------------------------------------------------- ' Proc: RTC_Set_DateTime ' Description: Sets the date and time in the DS1307. ' Arguments: day, mth, year, dow, hr, min (all of type Byte) ' Returns: None '--------------------------------------------------------------- 'Before using, check first if we are in 12h or 24h mode. 'If we store the hour in 12h format while in 24h mode, the AM/PM may not be correct. Proc DS1307_Set_DateTime(day As Byte, mth As Byte, year As Byte, dow As Byte, hr As Byte, min As Byte) Dim hour_register As Byte 'Read the hour register to insert the previous configuration. hour_register = DS1307_Read(0x02) 'Read the hour register (configuration + BCD hour). hr = Get_DecToBCD(hr) 'Convert the hour to BCD. 'Insert the previous configuration bits into the hour. If hour_register.6 = 1 Then 'If we are in 12h format. hr.5 = hour_register.5 'Preserve the previous AM/PM mode. hr.6 = 1 '12h mode. Endif 'Write the input data to the DS1307 in BCD format. Call DS1307_Write(0x04, Get_DecToBCD(day)) Call DS1307_Write(0x05, Get_DecToBCD(mth)) Call DS1307_Write(0x06, Get_DecToBCD(year)) Call DS1307_Write(0x03, Get_DecToBCD(dow)) Call DS1307_Write(0x02, hr) 'We already converted the hour to BCD earlier. Call DS1307_Write(0x01, Get_DecToBCD(min)) Call DS1307_Write(0x00, Get_DecToBCD(0)) ' Seconds set to zero. End Proc '--------------------------------------------------------------- ' Proc: RTC_Get_Date ' Description: Reads the date from the DS1307. ' Arguments: day, mth, year, dow (all of type Byte by reference (ByRef)) ' Returns: None '--------------------------------------------------------------- Proc DS1307_Get_Date(ByRef day As Byte, ByRef mth As Byte, ByRef year As Byte, ByRef dow As Byte) day = Get_BcdToDEC(DS1307_Read(0x04)) ' Read and convert the day to decimal mth = Get_BcdToDEC(DS1307_Read(0x05)) ' Read and convert the month to decimal year = Get_BcdToDEC(DS1307_Read(0x06)) ' Read and convert the year to decimal dow = Get_BcdToDEC(DS1307_Read(0x03)) ' Read and convert the day of the week to decimal End Proc '--------------------------------------------------------------- ' Proc: RTC_Get_Time ' Description: Lee la hora actual desde el DS1307. ' Arguments: hr, min, sec (todos de tipo Byte por ByRef) ' Returns: Ninguno '--------------------------------------------------------------- Proc DS1307_Get_Time(ByRef hr As Byte, ByRef min As Byte, ByRef sec As Byte) 'Lee el registro de la hora y borra los bit de configuración. hr = DS1307_Read(0x02) 'Leer registro de horas (configuración + hora en formato BCD). If hr.6 = 1 Then hr.5 = 0 'Si formato 12h borra bit AM/PM hr.6 = 0 'Borra formato 12h (en modo 24h no es necesario). hr = Get_BcdToDEC(hr) 'Pasa de BCD a decimal min = Get_BcdToDEC(DS1307_Read(0x01)) ' Lee y convierte los minutos. sec = Get_BcdToDEC(DS1307_Read(0x00)) ' Lee y convierte los segundos. End Proc '--------------------------------------------------------------- ' Proc: RTC_Set_Hour ' Description: Sets the time in the ds1307. ' Arguments: hout (Byte) ' Returns: None '--------------------------------------------------------------- 'Before using, check first if we are in 12h or 24h mode. 'If we store the hour in 12h format while in 24h mode, the AM/PM may not be correct. Proc DS1307_Set_Hour(hr As Byte) Dim hour_register As Byte 'Read the hour register to insert the previous configuration. hour_register = DS1307_Read(0x02) 'Read the hour register (configuration + BCD hour). hr = Get_DecToBCD(hr) 'Convert the hour to BCD. 'Insert the previous configuration bits into the hour. If hour_register.6 = 1 Then 'If we are in 12h format. hr.5 = hour_register.5 'Preserve the previous AM/PM mode. hr.6 = 1 '12h mode. Endif 'Write the input data to the DS1307 in BCD format. Call DS1307_Write(0x02, hr) 'We already converted the hour to BCD earlier. End Proc '--------------------------------------------------------------- ' Proc: RTC_Set_Minutes ' Description: Sets the Minutes in the DS1307. ' Arguments: minutes (type Byte) ' Returns: None '--------------------------------------------------------------- Proc DS1307_Set_Minutes(min As Byte) 'Write the input data to the DS1307 in BCD format. Call DS1307_Write(0x01, Get_DecToBCD(min)) End Proc'--------------------------------------------------------------- ' Proc: RTC_Set_Seconds ' Description: Sets the seconds in the DS1307. ' Arguments: seconds (type Byte) ' Returns: None '--------------------------------------------------------------- Proc DS1307_Set_Seconds(sec As Byte) 'Write the input data to the DS1307 in BCD format. Call DS1307_Write(0x00, Get_DecToBCD(sec)) End Proc ' Proc: DS1307_Set_DayOfWeek ' Description: Sets the day of week in the DS1307. ' Arguments: dow (day of week) (type Byte, value 1 to 7) ' Returns: None '--------------------------------------------------------------- Proc DS1307_Set_DayOfWeek(dow As Byte) 'Write the input data to the DS1302 in BCD format. Call DS1307_Write(0x03, Get_DecToBCD(dow)) End Proc ' Proc: DS1307_Get_DayOfWeek ' Description: Reads the day of week in the DS1302. ' Arguments: none ' Returns: day of week (type byte, value 1 to 7) '--------------------------------------------------------------- Function DS1307_Get_DayOfWeek() As Byte 'Read the data to the DS1302 in BCD format. ReturnValue Get_BcdToDEC(DS1307_Read(0x03)) ' Read and convert the day of the week to decimal. End Function '--------------------------------------------------------------- ' Proc: DS1307_SquareWave ' Description: Enables the square wave output on the DS1307. ' This function configures the control register to ' activate the square wave signal on the SQW/OUT pin. ' Arguments: freq (Byte) - The frequency of the square wave: ' 0: 1Hz ' 1: 4.096kHz ' 2: 8.192kHz ' 3: 32.768kHz ' Returns: None '--------------------------------------------------------------- Const DS1307_1hz = %00010000 Const DS1307_4096hz = %00010001 Const DS1307_8192hz = %00010010 Const DS1307_32768hz = %00010011 Const DS1307_DISABLE = %00000000 Proc DS1307_SquareWave(freq As Byte) ' Write the updated control register to the DS1307 Call DS1307_Write(0x07, freq) End Proc '--------------------------------------------------------------- ' Proc: DS1307_Write_RAM ' Descripción: Escribe un byte en la memoria RAM volatil del DS1307. ' Argumentos: address (Byte) - Dirección donde escribir (0 a 55). ' data (Byte) - Dato a escribir. ' Retorna: Ninguno. '--------------------------------------------------------------- Proc DS1307_Write_RAM(address As Byte, data As Byte) If address > 55 Then address = 55 'Rango 0 a 55, porque la RAM volatil del DS1307 es de 56 bytes. address = address + 0x08 ' Las direcciones de RAM comienzan en 0x08. Call DS1307_Write(address, data) ' Escribe el dato en la RAM. End Proc '--------------------------------------------------------------- ' Function: DS1307_Read_RAM ' Descripción: Lee un byte de la memoria RAM del DS1307. ' Argumentos: address (Byte) - Dirección de donde leer (0 a 55). ' Retorna: El valor leído de la RAM. '--------------------------------------------------------------- Function DS1307_Read_RAM(address As Byte) As Byte If address > 55 Then address = 55 'Rango 0 a 55, límite de la RAM del DS1307. address = address + 0x08 ' Las direcciones de RAM comienzan en 0x08. ReturnValue DS1307_Read(address) ' Lee el valor desde la RAM. End Function '--------------------------------------------------------------- ' Function: Get_DecToBCD ' Description: Converts a decimal value to its BCD format. ' Arguments: data (Byte) - Decimal value to convert. ' Returns: The value converted to BCD. '--------------------------------------------------------------- Function Get_DecToBCD(data As Byte) As Byte Dim nibh, nibl As Byte nibh = data / 10 ' Calculate the tens nibl = data - (nibh * 10) ' Calculate the units ReturnValue (nibh << 4) | nibl ' Return the value in BCD format End Function '--------------------------------------------------------------- ' Function: Get_BcdToDEC ' Description: Converts a BCD value to decimal. ' Arguments: data (Byte) - BCD value to convert. ' Returns: The value converted to decimal. '--------------------------------------------------------------- Function Get_BcdToDEC(data As Byte) As Byte Dim i As Byte i = data data = (i >> 4) * 10 ' Extract the tens data = data + (i & 0x0F) ' Extract the units ReturnValue data ' Return the decimal value End Function