sankar.m8
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Hi Friends
I have a problem regarding the 16x2 Dot matrix LCD display with PIC16F877A. I will just explain regarding the project. I need to control two relay (12V) for switching ON & OFF of a 230V supply. ULN ICs are used as a driver for relay interface. And a 2x16 LCD is interfaced in 4 bit mode.
Without providing 230V to the COM point of relay, the LCD interface is working fine. But when i am turning ON the 230V power supply, some random characters are displayed in the LCD panel. But the switching ON & OFF are working fine. I am switching the relay ON & OFF within a time of 250msec.
Is it an interference problem due to the AC supply switching? since the whole project is in a single PCB (15x10cm).
I couldn't figure it out the issue. Help me.
Thanks in advance
I have a problem regarding the 16x2 Dot matrix LCD display with PIC16F877A. I will just explain regarding the project. I need to control two relay (12V) for switching ON & OFF of a 230V supply. ULN ICs are used as a driver for relay interface. And a 2x16 LCD is interfaced in 4 bit mode.
Without providing 230V to the COM point of relay, the LCD interface is working fine. But when i am turning ON the 230V power supply, some random characters are displayed in the LCD panel. But the switching ON & OFF are working fine. I am switching the relay ON & OFF within a time of 250msec.
Is it an interference problem due to the AC supply switching? since the whole project is in a single PCB (15x10cm).
I couldn't figure it out the issue. Help me.
Thanks in advance