program keypad 4x3 for pic16f877a using ldmicro (by Mazlan)
I facing a problem on creating program fpr pic 16f877a, how keypad 4x3 can be program. The project is digital lock.
(no subject) (by Max)
Do you mean (how to scan a 4x3 matrix keypad)
If answer is yes, then the easiest way will be to supply 3 different voltage to the column wire... and read on 4 analog input the voltage of the 4 line wire
column #1 = 1 volt
column #2 = 2.5 volts
column #3 = 5 volts
So if you read between (450 and 560) 2.5V on analog line #1, you know that the key #2 has been pressed
and if you read more than (900) 5V on analog line #1, this is key #3
Hope this help
matrix keypad prog (by SEGAR)
hi, i wanna make programming with matrix keypad use password for operation any output ,but i don't have any idea for it, please if have any one done this programming in ldmicro please help to upload some information.
(no subject) (by SEGAR)
HI, this is not help me really, because in C Language is easily people are can makid,i not use c language to write programming in the MCU. i only use ladder language but i do no how to makid circuits to interface with pic16f887 / AT89C51 MCU with keypad or LCD display. i can see people are using Data connection witout use UART . if any one done before please send circuits and some information on this .
YOU CAN THE CIRCUITS DIAGRAM IN THE ATTACHMENTS