How to read pin 7 of port C on LM4F232H5QD

john krishna yaragorla

Dear all,
we are trying to read pin 7 of port C of LM4F232H5QD tiva micro controller ,the snippet of code for reading pin7 and configurations are attached.we are giving high signal from power supply but not able to read 1 from the pin 7 of port C...but when we are reading our variable that is value from the code for reading we are getting 128 or some junk value.Please let me know where is the issue.

over 10 years ago

0 Amit Ashara over 10 years ago

TI__Guru**** 244400 points

Hello John,

The return value of GPIOPinRead for a specific pin is either 0 or GPIO_PIN_x and not 0 and 1. You would need to change the value check.

Regards
Amit

0 john krishna yaragorla over 10 years ago in reply to Amit Ashara

Prodigy 200 points

thank you.it is returning GPIO_PIN_7.

0 Amit Ashara over 10 years ago in reply to john krishna yaragorla

TI__Guru**** 244400 points

Hello John,

As highlighted in another post the correct method is to use logical operator to ensure the correct pin match occurs in a multi input pin read on the same port.

Regards
Amit

0 cb1 over 10 years ago in reply to Amit Ashara

Guru 47900 points

Amit Ashara said:
GPIOPinRead for a specific pin is either 0 or GPIO_PIN_x and not 0 and 1.

While true for 7 of an 8 bit port's bits - GPIO_PIN_0 indeed will yield "1" - when the input signal rises above the (high) threshold level.

0 Amit Ashara over 10 years ago in reply to cb1

TI__Guru**** 244400 points

Hello cb1

True, but always well qualified to have it as GPIO_PIN_x

Regards
Amit

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How to read pin 7 of port C on LM4F232H5QD