performing logical NOT based on configurable data

Question

I would like to configure my switch input type as either active high or active low. I wrote below code and I know it will not work because I when I multiply by 0, nothing works. One way is to write code to check ACTIVE LOW using if statement and handle. But I am sure there could be a simple method to perform logical NOT operation based on configurable bits. How to make the readSwitch() function configurable depending on switch input types?

#define ACTIVE_LOW 0
#define ACTIVE_HIGH 1
#define SWITCH_TYPE ACTIVE_LOW

uint8_t readSwitch(uint8_t pinNum)
{
    uint8_t state=0;
    if(SWITCH_TYPE*(PINC&(1<<pinNum)))
    {
        _delay_ms(20);
        if(SWITCH_TYPE*(PINC&(1<<pinNum)))
        {
           state=1;
        }
    }
    return(state);
}

Why not to use "exclusive or"? `if (((PINC & (1 << pinNum)) != 0) ^ (ACTIVE_HIGH == 0)) .... ` if PINC bit is zero, and active high is not zero, or bit is not zero and ACTIVE_HIGH is zero then result would be true, and false otherwise — AterLux, Feb 19 '18 at 12:10

score 0 · Answer 1 · answered Feb 22 '18 at 01:31

0

Based on @AterLux comment and further analysis, below code could take care.

if(!(PINC&(1<<pinNum))^SWITCH_TYPE)

answered Feb 22 '18 at 01:31

Rajesh

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performing logical NOT based on configurable data

1 Answers1