A feature complete driver for the ISL1208 real time clock from Intersil.
Dependents: ISL1208_HelloWorld
Diff: ISL1208.h
- Revision:
- 0:697ca602e934
- Child:
- 1:c951ff6da740
diff -r 000000000000 -r 697ca602e934 ISL1208.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ISL1208.h Mon Sep 09 19:32:41 2013 +0000 @@ -0,0 +1,341 @@ +/* ISL1208 Driver Library + * Copyright (c) 2013 Neil Thiessen + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef ISL1208_H +#define ISL1208_H + +#include "mbed.h" + +/** ISL1208 class. + * Used for controlling an ISL1208 real time clock connected via I2C. + * + * Example: + * @code + * #include "mbed.h" + * #include "ISL1208.h" + * + * ISL1208 rtc(p28, p27); + * + * int main() + * { + * //Try to open the ISL1208 + * if (rtc.open(ISL1208::OSCILLATOR_CRYSTAL)) { + * printf("Device detected!\n"); + * + * //Check if we need to reset the time + * if (rtc.powerFailed()) { + * //The time has been lost due to a power complete power failure + * printf("Device has lost power! Resetting time...\n"); + * + * //Set RTC time to Wed, 28 Oct 2009 11:35:37 + * rtc.time(1256729737); + * } + * + * while(1) { + * //Get the current time + * time_t seconds = rtc.time(); + * + * //Print the time in various formats + * printf("\nTime as seconds since January 1, 1970 = %d\n", seconds); + * printf("Time as a basic string = %s", ctime(&seconds)); + * char buffer[32]; + * strftime(buffer, 32, "%I:%M %p\n", localtime(&seconds)); + * printf("Time as a custom formatted string = %s", buffer); + * + * //Delay for 1.0 seconds + * wait(1.0); + * } + * } else { + * printf("Device not detected!\n"); + * } + * } + * @endcode + */ +class ISL1208 +{ +public: + /** Represents the different oscillator modes for the ISL1208 + */ + enum OscillatorMode { + OSCILLATOR_CRYSTAL, /**< The internal crystal oscillator is enabled */ + OSCILLATOR_EXTERNAL /**< The internal crystal oscillator is disabled, an external 32kHz oscillator is connected to X1 */ + }; + + /** Represents the different output frequencies for the IRQ/fOUT pin on the ISL1208 + */ + enum OutputFrequency { + FOUT_DISABLED = 0, /**< Disable frequency generation on the IRQ/fOUT pin */ + FOUT_32768_HZ, /**< Generate 32.768kHz on the IRQ/fOUT pin */ + FOUT_4096_HZ, /**< Generate 4.096kHz on the IRQ/fOUT pin */ + FOUT_1024_HZ, /**< Generate 1.024kHz on the IRQ/fOUT pin */ + FOUT_64_HZ, /**< Generate 64Hz on the IRQ/fOUT pin */ + FOUT_32_HZ, /**< Generate 32Hz on the IRQ/fOUT pin */ + FOUT_16_HZ, /**< Generate 16Hz on the IRQ/fOUT pin */ + FOUT_8_HZ, /**< Generate 8Hz on the IRQ/fOUT pin */ + FOUT_4_HZ, /**< Generate 4Hz on the IRQ/fOUT pin */ + FOUT_2_HZ, /**< Generate 2Hz on the IRQ/fOUT pin */ + FOUT_1_HZ, /**< Generate 1Hz on the IRQ/fOUT pin */ + FOUT_1_2_HZ, /**< Generate 1/2Hz on the IRQ/fOUT pin */ + FOUT_1_4_HZ, /**< Generate 1/4Hz on the IRQ/fOUT pin */ + FOUT_1_8_HZ, /**< Generate 1/8Hz on the IRQ/fOUT pin */ + FOUT_1_16_HZ, /**< Generate 1/16Hz on the IRQ/fOUT pin */ + FOUT_1_32_HZ /**< Generate 1/32Hz on the IRQ/fOUT pin */ + }; + + /** Represents the power mode of the ISL1208 + */ + enum PowerMode { + POWER_NORMAL, /**< VBAT supply will be used when VDD < VBAT - VBATHYS and VDD < VTRIP */ + POWER_LPMODE /**< VBAT supply will be used when VDD < VBAT - VBATHYS */ + }; + + /** Represents the alarm mode of the ISL1208 + */ + enum AlarmMode { + ALARM_DISABLED, /**< The alarm function is disabled */ + ALARM_SINGLE, /**< Only a one-time match will be made between the RTC and alarm registers, and the IRQ/fOUT pin will pull low until the alarm flag is cleared */ + ALARM_INTERRUPT /**< Every time an alarm match is made the IRQ/fOUT pin will pull low for 250ms, the alarm flag does not have to be cleared */ + }; + + /** Represents the different battery mode ATR selections of the ISL1208 + */ + enum BatteryModeATR { + BMATR_ZERO = 0, /**< Delta capacitance = 0pF */ + BMATR_MINUS_0_5, /**< Delta capacitance = -0.5pF (≈ +2ppm) */ + BMATR_PLUS_0_5, /**< Delta capacitance = +0.5pF (≈ -2ppm) */ + BMATR_PLUS_1_0 /**< Delta capacitance = +1pF (≈ -4ppm) */ + }; + + /** Represents the different digital trim selections of the ISL1208 + */ + enum DigitalTrim { + DTR_ZERO = 0, /**< Digital trim = 0ppm */ + DTR_PLUS_20, /**< Digital trim = ≈ +20ppm */ + DTR_PLUS_40, /**< Digital trim = ≈ +40ppm */ + DTR_PLUS_60, /**< Digital trim = ≈ +60ppm */ + DTR_MINUS_20 = 5, /**< Digital trim = ≈ -20ppm */ + DTR_MINUS_40, /**< Digital trim = ≈ -40ppm */ + DTR_MINUS_60 /**< Digital trim = ≈ -60ppm */ + }; + + /** Create a ISL1208 object connected to the specified I2C pins + * + * @param sda The I2C data pin. + * @param scl The I2C clock pin. + */ + ISL1208(PinName sda, PinName scl); + + /** Probe for the ISL1208 and configures the oscillator mode if present + * + * @param mode The oscillator mode. + * @returns + * 'true' if the device exists on the bus, + * 'false' if the device doesn't exist on the bus. + */ + bool open(OscillatorMode mode); + + /** Get the current time from the ISL1208 + * + * @returns The current time as a Unix timestamp. + */ + time_t time(void); + + /** Set the current time on the ISL1208 from a Unix timestamp + * + * @param t The current time as a Unix timestamp. + */ + void time(time_t t); + + /** Determine whether the RTC has completely lost power (and hence the time and SRAM) + * + * @returns Whether or not the RTC has completely lost power. + */ + bool powerFailed(void); + + /** Determine whether the RTC has been on battery backup + * + * @returns Whether or not the RTC has been on battery backup. + */ + bool batteryFlag(void); + + /** Clear the battery backup flag + */ + void clearBatteryFlag(void); + + /** Determine whether the alarm has matched the RTC + * + * @returns Whether or not the alarm has matched the RTC. + */ + bool alarmFlag(void); + + /** Clear the alarm flag + */ + void clearAlarmFlag(void); + + /** Get the current output frequency on the IRQ/fOUT pin + * + * @returns The current output frequency. + */ + ISL1208::OutputFrequency foutFrequency(void); + + /** Set the output frequency on the IRQ/fOUT pin + * + * @param freq The new output frequency. + */ + void foutFrequency(OutputFrequency freq); + + /** Determine whether or not the IRQ/fOUT pin will continue to output on battery power + * + * @returns Whether or not the IRQ/fOUT pin will continue to output on battery power. + */ + bool outputOnBattery(void); + + /** Set whether or not the IRQ/fOUT pin should continue to output on battery power + * + * @param output Whether or not the IRQ/fOUT pin should continue to output on battery power. + */ + void outputOnBattery(bool output); + + /** Get the current power mode of the ISL1208 + * + * @returns The current power mode as a PowerMode enum. + */ + ISL1208::PowerMode powerMode(void); + + /** Set the power mode of the ISL1208 + * + * @param mode The new power mode as a PowerMode enum. + */ + void powerMode(PowerMode mode); + + /** Get the current alarm mode of the ISL1208 + * + * @returns The current alarm mode as an AlarmMode enum. + */ + ISL1208::AlarmMode alarmMode(void); + + /** Set the alarm mode of the ISL1208 + * + * @param mode The new alarm mode as an AlarmMode enum. + */ + void alarmMode(AlarmMode mode); + + /** Get the current analog trim of the ISL1208 + * + * @returns The current analog trim in pF. + */ + float analogTrim(void); + + /** Set the analog trim of the ISL1208 + * + * @param trim The new analog trim in pF (valid range 4.5pF to 20.25pF in 0.25pF steps). + */ + void analogTrim(float trim); + + /** Get the current battery mode analog trim of the ISL1208 + * + * @returns The current battery mode analog trim as a BatteryModeATR enum. + */ + ISL1208::BatteryModeATR batteryModeATR(void); + + /** Set the battery mode analog trim of the ISL1208 + * + * @param mode The new battery mode analog trim as a BatteryModeATR enum. + */ + void batteryModeATR(BatteryModeATR atr); + + /** Get the current digital trim of the ISL1208 + * + * @returns The current digital trim as a DigitalTrim enum. + */ + ISL1208::DigitalTrim digitalTrim(void); + + /** Set the digital trim of the ISL1208 + * + * @param mode The new digital trim as a DigitalTrim enum. + */ + void digitalTrim(DigitalTrim dtr); + + /** Get the alarm time from the ISL1208 + * + * @returns The current alarm time as a Unix timestamp (with the current year) + */ + time_t alarmTime(void); + + /** Set the alarm time on the ISL1208 from a Unix timestamp + * + * @param t The alarm time as a Unix timestamp. + * @param sc Enable or disable seconds matching. + * @param mn Enable or disable minutes matching. + * @param hr Enable or disable hours matching. + * @param dt Enable or disable date matching. + * @param mo Enable or disable month matching. + * @param dw Enable or disable day of week matching. + */ + void alarmTime(time_t t, bool sc = true, bool mn = true, bool hr = true, bool dt = true, bool mo = true, bool dw = true); + + /** Read the contents of the battery-backed SRAM + * + * @returns The current contents of the SRAM. + */ + unsigned short sram(void); + + /** Write new data to the battery-backed SRAM + * + * @param data The new data for the SRAM. + */ + void sram(unsigned short data); + +private: + //I2C register addresses + enum Register { + REG_RTC_SC = 0x00, + REG_RTC_MN, + REG_RTC_HR, + REG_RTC_DT, + REG_RTC_MO, + REG_RTC_YR, + REG_RTC_DW, + REG_CTL_SR, + REG_CTL_INT, + REG_CTL_ATR = 0x0A, + REG_CTL_DTR, + REG_ALM_SCA, + REG_ALM_MNA, + REG_ALM_HRA, + REG_ALM_DTA, + REG_ALM_MOA, + REG_ALM_DWA, + REG_USR_USR1, + REG_USR_USR2 + }; + + //Member constants + static const int m_ADDR = (0x6F << 1); + + //Member variables + I2C m_I2C; + + //Internal functions + char read8(char reg); + void write8(char reg, char data); + unsigned short read16(char reg); + void write16(char reg, unsigned short data); + unsigned int bcd2bin(unsigned char val); + char bin2bcd(unsigned int val); +}; + +#endif