pic16f84 with numeric keypad and three 7 segment display?

Question

I am studying Computer Engineering and want to create a product using pic 16f84 micro controller inter face with a numeric keypad and 3 seven segment display....

I want is, if I type 0-9 the 1st three characters will be displayed on the 7 segment and display. that can be save and recalled when push the / and * respectively. Is there anyway to interface the numeric keypad to the pic?

If you can provide the circuit diagram and the .asm file or any other help it will be greatly appreciated , Thank you

Answer 1

This project shows how to interface a keypad to a PIC16C84, but the notes say it can be interfaced to a 16F84 with only a few minor changes.

http://www.nomad.ee/PIC/keypad.zip



The current version of the chip is 16F84A, not 16F84.



I think there is a problem in that the 16F84A (and 16F84) has only 13 I/O pins. If you use 8 for the keypad, that leaves 5. The 7 segment display will want 4 for data an at least 2 for digit select. You could consider selecting a chip with more I/O pins:

http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1002&mid=10&lang=en&pageId=74

Answer 2

in case you had to be waiting to modify independently 4 cases seven segments you may want to favor 28 wires. to shrink again the type of wires a way referred to as multiplexing is amazingly effortless. in this technique 7 wires are used to modify the seven segments and four wires (A B C D) are used to modify which digit is lively. The kit (frequently a micro-controller) runs precise right here software: a million/ merely the first 7 section educate is activated (wire A is lively B,C,D are inactive) and the 7 wires are used to gentle the needed section for the first digit. 2/ the 2d 7 section educate is activated (wire B) and the segments linked with 2d digit are lit 3/ similar for 0.33 digit 4/ similar for 4 th digit 5/ bypass again to step a million In summary ========= At any time merely digit is lively (the three diverse digit are off) yet this is going so right now that the interest does not see it speedy on/off flash and the man sees the educate as notwithstanding all digits the position good displayed each and each and each and each of the time.

Answer 3

here i attach link you'll find the useful all useful stuff including circuit diagram,Proteus simulation and code written in c language

http://www.projectsguru.net/projects/8051-microcontroller/53-keypad-based-seven-segment-display