lpc1768 EXTINT interface

[Sukumar_M]

Hi,

I Try to config ir sensor in lpc1768 but it produce unwanted ripples so if i check the output connection should be active how to deactivated the output pin.

[xiangjun_rong · Accepted solution]

Hi,

As you know that the uart can transmit irDa signal from it's Uartx_TX pin, which is a bit stream modulated by the 38KHz signal, the 38khz fixed duty cycle signal can be generated by uart module itself. If you want LPC uart_rx pin to receive the irDa signal, I suppose that you have to create an analog low-pass filter circuit to remove the 38K modulated signal, then use uart_RX pin to receive the filtered data stream.

For the EXTINT pin, it is an input pin, which can accept external signal to fire interrupt.

If I misunderstand you, I am sorry.

BR

XiangJun Rong

[Sukumar_M]

But EXTINT also use For an Counting purpose

[xiangjun_rong]

Hi,

If you want to count external clock number, you can connect the external clock signal to the Timer Capx pin, by proper configuration, the Timer will count the number of external clock signal.

Hope it can help you

BR

XiangJun Rong