ALL CATEGORIESPerpetual calendar production based on PCF8563 clock chip
Solution Introduction
There are many perpetual calendar clock chips, but compared to DSl302, Philips PCF8563 clock chip and LCM1602 are used for display, which can achieve better results. The circuit diagram is shown in the figure.
PCF8563 is a low-power CMOS real-time clock / calendar chip. It provides a programmable clock output, an interrupt output, and a power-down detector. All addresses and data are transferred serially through the I2C bus interface. The maximum bus speed is 400kbit / s. As long as the I2C bus mode is operated during data exchange, the timing requirements are not too high. PCF8563 internal register address and data format description are shown in the attached table.
|
Unit classification |
address |
Data Format |
|
|
|
Second unit |
02H |
Exact |
BCDdata, 1011001 59 seconds |
|
|
Minute unit |
03H |
invalid |
BCDdata 00-59 |
|
|
Hour unit |
04H |
invalid |
BCDdata, 00-23 |
|
|
Day unit |
05H |
invalid |
BCDdata, 01-30 BCD data, 01-31, February is 29 |
|
|
Week Unit |
06H |
invalid |
0-6 |
|
|
Monthly unit |
07H | century, invalid |
BCDdata, 01-12 |
|
|
Annual unit |
08H |
|
BCDdata, 00-99 |
|
|
Minute Alarm unit |
09H |
Alarm is active |
Alarm value 0-59 |
|
| Hour Alarm unit | 0AH |
Alarm is active |
Alarm value 0-23 |
|
| Annual alarm unit | 0BH | Alarm is active | Alarm value 0-30 |
|
| Week alarm unit | 0CH | Alarm is active | Alarm value 0-6 |
|
| CLKOUT | 0DH | Forbid/valid | invalid frequency 11.1 HZ output |
|
| Countdown unit | 0EH | TE | invalid |
|
This circuit uses 89S51 as the main control MCU, PCF8563 generates clock information, and LCM1602 liquid crystal module is used for display. Y1 is a 32.768kHz crystal and Y2 is a 12MHz crystal. BT1 is used as a backup power source to keep the clock data from being lost for 10,000 years; RP1 and RP2 are 9-pin 10kΩ resistors; S1 ~ S4 are used to adjust the time. S2 is used to enter the adjustment mode; and each time you press to change the adjustment item; S1 is used to exit the adjustment state, S3, S4 is used to add 1 minus 1 operation.
Key Components
| No. | Part Number | Manufacturer |
|---|
