Port PIN_E2 as digital output

prayami · Joined: 22 Dec 2004 Posts: 78

Hi..

I am using PIC18F4525 using PCH compiler.

I am using PIN_E0, PIN_E1 and PIN_E2 as digital output.

The PIN_E0 and PIN_E1 are working fine. But PIN_E2 does not
change the output even though I change it programatically.

That means LEDs on PIN_E0 and PIN_E1 are working but on PIN_E2
is not working.

I set TRISE as under:

set_tris_e(0); //All output

What can be problem?

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

prayami · Joined: 22 Dec 2004 Posts: 78

Sorry...

Instead of PIN_E0,PIN_E1 and PIN_E2, I have by mistake written

PIN_E1,PIN_E2 and PIN_E3. I have modified the same in my original
question.

That means I/O on PIN_E2 is not working.

I am not using PIN_E3. The MCLR/PIN_E3 is connected to +5 V using
Pullup register.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

There are several possible reasons:

Hardware:
1. The LED on Pin E2 could be installed with reversed polarity.
2. The LED could be defective.
3. The series resistor used with the LED may have a value that
is too large, so the LED is not very bright. (Try using 330 ohms).
4. One of the connections in the LED circuit may be broken.

Software:
1. Port E may not be properly configured for digital i/o.
The compiler is supposed to configure all analog pins as
digital i/o in its start-up code. But, sometimes CCS does not
do this correctly. So, you may need to do it manually, by
adding this line near the beginning of your program: