7 Segment Clock With Temperature Display [ds18b20 and 5 Digit Display]

5 digit seven  segment clock with temperature display.

PIC16F877A based  clock
 
1, High-precision  temperature sensor   ds18b20
2, ds1307 RTC
3, 4 switches, easy time adjust option
4, alternating temperature and time display method
5, pic16f877a micro-controller
6, half hour notification  - single beep
7, hour notification   - double beep
8, buzzer notification for key press

components

1, BC 558 -5
2, resistors 330 Ohm  - 10
3, common anode seven segment LED display - 5
4, acrylic sheet

ds18b20 sensor
http://datasheets.maximintegrated.com/en/ds/DS18B20.pdf

ds1307 RTC
http://datasheets.maximintegrated.com/en/ds/DS1307.pdf


Overview of 1-Wire Technology and Its Use
By:   Bernhard Linke, Principal Member Technical Staff
Jun 19, 2008

Abstract: This article provides a general overview of the 1-Wire® technology, its communication concept and, as a benefit of the low pin count, unusual package options. The main section discusses 1-Wire devices by their feature set and explains the typical applications. The article ends with practical information on how to evaluate 1-Wire devices, explains device customization options, and references resources that assist customers in integrating 1-Wire technology in their systems.


What Is 1-Wire Technology?

The basis of 1-Wire® technology is a serial protocol using a single data line plus ground reference for communication. A 1-Wire master initiates and controls the communication with one or more 1-Wire slave devices on the 1-Wire bus (Figure 1). Each 1-Wire slave device has a unique, unalterable, factory-programmed, 64-bit ID (identification number), which serves as device address on the 1-Wire bus. The 8-bit family code, a subset of the 64-bit ID, identifies the device type and functionality. Typically, 1-Wire slave devices operate over the voltage range of 2.8V (min) to 5.25V (max). Most 1-Wire devices have no pin for power supply; they take their energy from the 1-Wire bus (parasitic supply).

What Is Special About 1-Wire?

1-Wire is the only voltage-based digital system that works with two contacts, data and ground, for half-duplex bidirectional communication. In contrast to other serial communication systems such as I²C or SPI, 1-Wire devices are designed for use in a contact environment. Either disconnecting from the 1-Wire bus or a loss of contact puts the 1-Wire slaves into a defined reset state. When the voltage returns, the slaves wake up and signal their presence. With only one contact to protect, the built-in ESD protection of 1-Wire devices is extremely high. With two contacts, 1-Wire devices are the most economical way to add electronic functionality to nonelectronic objects for identification, authentication, and delivery of calibration data or manufacturing information.


for more details:






ds1307 Key Features

    Real-Time Clock (RTC) Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the week, and Year with Leap-Year Compensation Valid Up to 2100
    56-Byte, Battery-Backed, General-Purpose RAM with Unlimited Writes
    I²C Serial Interface
    Programmable Square-Wave Output Signal
    Automatic Power-Fail Detect and Switch Circuitry
    Consumes Less than 500nA in Battery-Backup Mode with Oscillator Running
    Optional Industrial Temperature Range: -40°C to +85°C
    Available in 8-Pin Plastic DIP or SO
    Underwriters Laboratories (UL) Recognized

there are 4 micro switch

SEL/EXIT    [selection or Exit ]  
Up                [increment ]
Down          [Decrement]
Set              [Update the last change]


step 1:   wait for the time display  [ switches function disabled  at time display mode  ]

step 2:  
                step 2.a
                              Press  the SEL/EXIT switch
                              hour option selected    [Up and Down button for hour ]
               step 2.b
                              Press again the SEL/EXIT switch
                             minute option selected    [Up and Down button for minute ]
               step 2.c
                            Press again the SEL/EXIT switch
                            AM/PM option selected    [Up and Down button for AM/PM selection ]

               step 2.d
                            Press again the SEL/EXIT switch
                            it cancel the change  and exit from updating mode
                            if you want to save the change don't press  the  SEL/EXIT  button 

step 3:      SET Button     
                   update the last change  

hex file  rtc_temp_clock.hex

 crystal 20 MHz | watch dog timer off | code protection off