problem in configuring pins as inputs in 16F628A

[hemnath]

Hi,
I worked lots of projects using PIC18 microcontroller.
Now I am in need of using PIC16F628A for a project. Crystal used 6.144Mhz.
I have configured the B4-B7 pins as inputs using TRIS register.

TRISB = 0b11110000;

But when i measure the voltage at B7 pin, it shows +5V. I have left the pin open.

What could be the problem.

Thanks in advance

 

[mathespbe]

Check your board connection...

 

[deeplearns]

try pulling them down through 10 k resistor to ground if you want them to be initialized to be zero always .Also when a port is generally set as input it has a floating value so it is generally in the range of 3 to 5 v So this might be the case here . Also check POR values of the PORTB ,and OPTION_REG for RBPU . Also first thing to check would be board connections as mentioned above .

 

[hemnath]

Please check the file. I have connected like this in my hardware.
when the switch is open, Voltage across R2-R3 is around 4V.

 

[Venkadesh_M]

put a 10k instead of 76k..

 

[hemnath]

yeah ok ..
But i don't think that those resistor value could cause the problem. They are used to limit the current.

Let me check it and get back to you soon.

Thank you

 

[Venkadesh_M]

both resistors in series shd have 10k... if u didnt got output, post project file.....