InetrfaceProducts NXP
PCF2127 and PCF2129 are high accuracy real-time-clock (RTC) module. This library provides simple interface to accessing clock information.
Dependents: PCF2127_Demo PCF2127_Hello
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PCF2127 and PCF2129¶
PCF2127T is in SO16 package
The PCF2127 and the PCF2129 are a CMOS Real Time Clock (RTC) and calendar with an integrated Temperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz crystal optimized for very high accuracy and very low power consumption.
Both of PCF2127 and PCF2129 have a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features.
On addition to this, the PCF2127 has 512 bytes of general-purpose static RAM.
These 4 types of RTC modules are software compatible. So this library "PCF2127" can be used all of those.
This library only supports I2C to communicate with the PCF2127/PCF2129.
Type variations¶
Main feature difference¶
| type | +/-3ppm accuracy range | 512 bytes RAM | package |
|---|---|---|---|
| PCF2127T | -30℃ to +80℃ | yes | SO16 |
| PCF2127AT | -30℃ to +60℃ | yes | SO20 |
| PCF2129T | -30℃ to +80℃ | not available | SO16 |
| PCF2129AT | -15℃ to +60℃ | not available | SO20 |
Pin assign¶
PCF2127T
Connection between MCU and PCF2127/PCF2129¶
These examples show how the RTC module can be connected via I2C bus.
References¶
- Datasheet
- User manual
- Other information PCF2127