I had connected the enable of LCD to pin P0.27 of LPC1769 which shares the SDA0 of I2C 0 and pin P0.28 to DB0(of LCD).The same serves as the SCL for I2C 0.Now the LCD is not working fine.What may be the reason?

[archanaravindra]

Can the problem be solved if the PINSEL is wisely configured?

[kerryzhou]

Hi Archana Ravindran,

    P0.27 and P0.28 is the true open-drain pin.

    So, please add external pullup up in these two pins, then try again.

Wish it helps you!

If you still have question about it, please let me know!

Have a great day,
Kerry

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[archanaravindra]

Thanks Kerry Zhou.Afterwards I had pulled up both the pins to 5v.The LCD commands are received correctly.But now also the problem persists.

[kerryzhou]

Hi Archana Ravindran,

   What the problems you are meeting now?

   Check the pin waveform with the oscilloscope, whether the wave in these two pin is correct?

   If the pin wave is correct, you need to check your software code which communicate with your LCD, it should meet the LCD command demand.

Have a great day,
Kerry

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