How to check the input with ATMEGA32?

[ahmed_mahmoud]

I use gcc compiler WinAVR and I want to check the input

if(PINB0==1)
{
//do something
}

However, when I set the B0 nothing happens, but when I use

if((PINB&0x01)==0x01)
{
//do something
}

it works perfectly; nevertheless, its not practical to write like that each time i use if condition.

Regards,
Ahmed

 

[alexan_e]

I'm not even sure what is the definition of PINB0 but you can use any of the solution I have posted in the following post
https://www.edaboard.com/threads/166246/#post894717

Alex

 

[georgz]

if(PINB0==1)
{
//do something
}

PINB0 is not 1, the code will never execute.

However, when I set the B0 nothing happens, but when I use

if((PINB&0x01)==0x01)
{
//do something
}

This one works because 0x01 is equal to 0x01 AND probably one or more pins of the PINB are equal to 1.

Some of the pins have two or three different functions, you have to check the datasheet and figure out at what function is set the pin on start up. Then you need to enable the function that you want by setting
certain bits to zero or one. Again check the datasheet.

 

[Tahmid]

If you check the header file "iom.h", you'll see that PINB0 is defined as the constant 0. So, your condition is never true. So, you cannot use the 1st method. I've attached the header file but I changed the extension to .txt so that you can see for yourself.

Hope this helps.
Tahmid.

 

[ahmed_mahmoud]

Dear all,
your replies are highly appreciated.can I use "PINB.0" I saw some codes use this command; however, read that it compiler dependent.

regards,
Ahmed

 

[georgz]

Does it work?? Probably not if it's constantly 0. You could try a different input.

 

[alexan_e]

Read the link of post #2, this can only be used in codevision but you can do something similar with avrgcc

Alex

 

[Tahmid]

Dear all,
your replies are highly appreciated.can I use "PINB.0" I saw some codes use this command; however, read that it compiler dependent.

regards,
Ahmed

You can't use PINB.0 in AVR-GCC. That works in Codevision and mikroC. In AVR-GCC you cannot refer to a bit like that.

 

[alexan_e]

You can have bit access if you use the following

---

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// structure to allow bit field operations, name conversions: PORTA.0 -> PORT_A.b0  PORTB.7 -> PORT_B.b7
typedef struct{ uint8_t b0:1;
                uint8_t b1:1;
                uint8_t b2:1;
                uint8_t b3:1;
                uint8_t b4:1;
                uint8_t b5:1;
                uint8_t b6:1;
                uint8_t b7:1; } bits;
 
// define all the ports of your microcontroller
#define PORT_A (* (volatile bits *) &PORTA)
#define PIN_A (* (volatile bits *) &PINA)
#define DDR_A (* (volatile bits *) &DDRA)
 
#define PORT_B (* (volatile bits *) &PORTB)
#define PIN_B (* (volatile bits *) &PINB)
#define DDR_B (* (volatile bits *) &DDRB)
 
// ...define any other available ports
 
// then you can use like this to write or read specific bits
PORT_A.b0=1;   // write value to PORTA bit 0
PIN_B.b4=0;   // write value to PINB bit 4

---

The names used (PORT_A, PIN_A etc) can be changed but you have to use a name that is not defined.
You can also change b0, b1 etc to any other name

Alex