Hi everybody,

I need to use 3 outputs of a 12F629 switching to ground, not to the 5V. It's been impossible to find such information, maybe can not be done. I do not see nothing related to that in the GPIO register. Any idea how to do it within the hex file?
By the way, another question. Without touching anything, the output is=5V when enabled, but when it is disabled, what do I have there? Open circuit?

Many thanks

 

If you look at paragraph 3.1 in the datasheet it shows how to set up the port for I/O.
Clear any bits in TRISIO that you want to use as outputs.
To set the output pins high or low set or clear the matching bits in GPIO.

 

hi Alex,
Welcome to AAC.
Post your program Code.
E

 

Thanks but I'm gonna need more help, I am totally new in this. I've made a code very simple, flashing 3 outputs:

AllDigital
TRISIO = %100000 'GPIO: 0 = salidas
CMCON = %00000111 'deshabilita comparadores

Symbol rojo = GP0
Symbol amarillo = GP1
Symbol verde = GP2
'Symbol entrada = GP5
'Define SIMULATION_WAITMS_VALUE = 1

inicio:

rojo = 1
amarillo = 1
verde = 1
WaitMs 1500
rojo = 0
amarillo = 0
verde = 0
WaitMs 200


Goto inicio

Thank you

 

If you use the internal oscillator you have 6 I/O ports. 5 of them are Read/write. One of them (GPIO3) is read only. If you use an external crystal oscillator you lose 2 of the R/W ports. You can set5 individual bits to zero (0 volts.) with a bit clear instruction. (BCF)

Les.

 

Thanks but not understand, the question was about to change the logical of the 3 outputs.

 

Are you using the GPIO pins to source or sink current. Can you show a schematic of how one LED is connected to a pin?

 

I am using as a source, I want to use them as sink. I need the output set to ground when enabled, not set to 5V.

 

The output is switched to ground whenever you set it to zero.

Bob

 

You need an initial command to set the outputs in question to one,
Clear the port pin when turning on.
Max.

 

Given these two choices:


You have them wired as in "B." Have you re-wired them as in "A?" Is that corret?

 

Also, at power up, the ports default to high impedance inputs, in your set up, set the ports to outputs and set to a 1 right away.
Clear the output to zero turn on LED.
Max.

 

You also need to set the pins to digital: 'ANSEL =0'

 

That might be real tricky for the 12F629. Where do you find that register?

 

Its in bank 1 and also referenced on P19 of the manual.
Max.

 

I am surprised dear friend. Have either of you looked at the datasheet:



As they say, ignore the asterisk and its your asterisk.

 

Yes, but you need to notice that the datasheet covers both '629 and '675!

 

You also need to set the pins to digital: 'ANSEL =0'

Yes, but you need to notice that the datasheet covers both '629 and '675!

And how do you set ANSEL in the 12F629? Did you notice that the datasheet covers both?

The first LED I ever flashed was with a 12F508. The 12F509 was a move up. The 12F683 was almost overwhelming, so I have not gone much further, nor have I needed to.

 

So its no problem, the 12f629 does not have A/D registers!
Hence no ANSEL!
Max.

 

At this point, I think the TS needs to tell us how it is wired. When he/she says "sourced," I think that means "B." I wounder whether the design has been changed to "A" to accommodate "sinking."