Digital Clock and Temperature Block Diagram and Schematic

Digital Clock and Temperature
This is a digital clock and temperature display which is alernate display between time and temperature.
Feature
- Display time 24-hour format. 00:00 – 23:00
- Use DS1307 RTC with 3V betterry back-up.
- 1 channel temperature sensor(DS1820)
- measures temperatures from -55 to + 125 degree Celsius.
- Temperature accuracy 0.5 ‘C
- software compiled with CCS C compiler V 3.222
Block diagram

The figure 1. is a block diagram for digital clock and digital thermometer.It consists of 1 temperature sensor, RTC ,Microcontroller(PIC), shift register ,7-segment and key board.The shift register use for expand I/O of CPU becuase it has 13 I/O only for PIC16F826.This shift register is a device contains an 8-bit serial-in, parallel-out shift register that feeds an 8-bit D-type storage register.

Schematic


Figure 2. is the schematic for this project.PIC16F628 used to control all task such read temperature,read RTC from DS1307
convert data to 7-segment code .The detail of power supply not show in the circuit.
Note : you must converting 7-segment pin for two right digits or digit for minute by change Segment A to D, B to E, C to F and so on.