LCD and 4x4 Keypad on the Same port & DTMF using PWM - Electronic Circuits Projects Diagrams Free

lee_man_tbu · 9th December 2003, 08:43 PM

Hey everyone

Can someone please tell me how too connect a LCD and 4x4 keypad using on 8-bit I/O Port on a PIC MCU?

I konw the data bits that the LCD will see will not affect it's operation becuase the E and RS lines and seperate, but i am unsure if i need too make the LCD Run in 4-bit mode or can i still use the LCD and 8 Bit mode and have the 4x4 keypad work properly.
I want the Rows of the Keypad connected to the Lower 4 Bits(Outputs) and the Cols. of the keypad connected too the the upper 4 Bits(inputs).

Also, has anyone ever used the hardware PWM too generate a DTMF signal, and if so, how ?

Any help on this matter would be great

Thanks

Lee Stoner

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9th December 2003, 08:43 PM	(permalink)
lee_man_tbu	LCD and 4x4 Keypad on the Same port & DTMF using PWM Hey everyone Can someone please tell me how too connect a LCD and 4x4 keypad using on 8-bit I/O Port on a PIC MCU? I konw the data bits that the LCD will see will not affect it's operation becuase the E and RS lines and seperate, but i am unsure if i need too make the LCD Run in 4-bit mode or can i still use the LCD and 8 Bit mode and have the 4x4 keypad work properly. I want the Rows of the Keypad connected to the Lower 4 Bits(Outputs) and the Cols. of the keypad connected too the the upper 4 Bits(inputs). Also, has anyone ever used the hardware PWM too generate a DTMF signal, and if so, how ? Any help on this matter would be great Thanks Lee Stoner