Incorrect high value for PIC16F84

[alexeygu]

I am using a PIC16F84A and just starting out. I had it output a high (1), and expected to receive 5V, however I only received 0.5V. When I tell it to output low (0), I receive 0.2-0.3V. Any ideas why this is happening?

 

[GraveYard_Killer]

it shouldn't be like that. did you program it correctly? is the mclr connected to vcc?

 

[Nigel Goodwin]

Make sure you are setting the pin as an output, also use a pin on PortB, not PortA - PortA has one pin which is opencollector (so can't go high).

Failing that, post your code here.

 

[alexeygu]

I didn't have anything hooked up to MCLR. I hooked it up with a 6.8k resistor and now the high is 5V and the low is 4.5V. Below is my code from SourceBoost that sets port B to low.

#include <system.h>

const char led[6] = { 1, 2, 4, 8, 16, 32 };

void delay( void )
{
    char i = 0, j;
    while( i++ < 5 )
    {
        j = 0;
        while( j++ < 2 )
        {
            nop();
        }
    }
}

main()
{
    disable_interrupt( GIE );
    trisb = 0;

    set_tris_b(0x00);

    char i = 0;
    while( 1 )
    {
		output_port_b( 0x00 );
		portb = 0x00;    
    }
}

 

[Nigel Goodwin]

What type of oscillator are you using?, and are the config fuses set correctly?.

 

[StupidDum]

First of all, probe the power and ground pins on your pic.