Various types of soccer substitution board are easily available in market but these all are very expensive (cost around $200). So, I decided to design a project called DIY Soccer Substitution Board using AT89C51. The feature of the project DIY soccer substitution board is listed below.
- Low cost and low maintenance.
- Microcontroller based system thus programmed as per our wish
- Simple and easily understandable circuit and code.
- Four individual buttons switch to increase and decrease the score of two team.
Circuit Description of DIY Soccer Substitution Board using AT89C51
The circuit diagram of DIY Soccer Substitution Board using AT89C51 is shown in figure 1. It is designed using AT89C51 (8-bit microcontroller), 7447 (BCD-to-7 segment decoder), 7-segment display and few other electronic components for working flawlessly of circuit. The working of the circuit is quite straight forward, any one with little knowledge about AT89C51 can easily understand.
AT89C51 is used because of their rich features suitable for various application. And main reason for using AT89C51 microcontroller is that it meets all the criteria for microcontroller selection.
External access pin EA (pin 31) is connected with Vcc because it is executed from internal program memory. As there no external memory, pins of port 0 must be connected externally to a 10K pull-up resistors as they are open drain. Reset pin must have the min. duration of 2 machine cycle. When power is turned on, the circuit holds the RST high for an amount of time that depends on the capacitor value and the rate at which it charges. To ensure a valid reset, the RST pin must be held high long enough to allow the oscillator to start up pulse two machine cycle. Thus, we had used 10uf capacitor with a resistor connected in series.
7447 is a BCD-to-7 segment decoder, this type of decoder accepts the BCD information and converts it into seven outputs for connection to a 7-segment display. These numerical displays can be implemented by light-emitting diodes (LEDs), liquid crystal display (LCD), gas discharge display etc. The 7-segment outputs are connected directly connected to 7-segment display as shown in circuit diagram. This ICs are used to display BCD information on 7-segment numerical displays. They are found in multimeter, counter, other test equipment, commercial electronic scales, and wherever a numerical read-out is required.
Software: The software code of DIY Soccer Substitution Board using AT89C51 is written in assembly and compiled using keil u version 5. The simulation of DIY Soccer Substitution Board is done using Proteous 8 professional. You can directly download the software from the link below.
PARTS LIST OF DIY SOCCER SUBSTITUTION BOARD USING AT89C51
|Resistors (all ¼-watt, ± 5% Carbon)|
|R1 – R8 = 10 KΩ
R9 = 1 KΩ
|C1, C2 = 33pF
C3 = 10 µF/16V
|IC1 = AT89C51
IC2 – IC5 = 7447 (BCD to 7 segment decoder)
Four 7 segment displays
|X1 = 12 MHz crystal oscillator
SW1 – SW5 = Push to on switch