PIC12F683 pin GP3 as output

[louislouis]

Hello,
finally success. I grab one of my PICAXE 08M2, read it with pickit programmer (destroy the bootloader) and yes, it is a PIC12F1840 not a 12F683 which is a previous version of PICAXE 08M (Richard has good suggestion).

OK, back to my question if it is possible to use the GP3 (MCLR) pin as digital output on this 12F1840 yes, it is!
This method is suitable to switch simple devices like relays, LEDs, etc. The state is only 1 or 0 (on/off).
All done with enabling or disabling the GP3 pin internal pull-up resistor. The circuit is the same as in my previous post, and the example code for PIC12F1840 LED blinking on GP3 is like:

;PIC 12F1840
#CONFIG
  __config _CONFIG1, _FOSC_INTOSC & _WDTE_OFF & _PWRTE_ON & _MCLRE_OFF & _CP_OFF & _CPD_OFF & _BOREN_ON & _CLKOUTEN_OFF & _IESO_ON & _FCMEN_ON
  __config _CONFIG2, _WRT_OFF & _PLLEN_ON & _STVREN_ON & _BORV_19 & _LVP_OFF
#ENDCONFIG

DEFINE OSC 32    ; Use internal clock 
OSCCON = %01110000
CLKRCON = 0

TRISA = %000000
ANSELA = 0  
OPTION_REG.7=0  ; Enable internal pull-ups

strt:
wpua=%001000
PAUSE 500
wpua=%000000
PAUSE 500
goto strt

The LED is on when pull-up is set ON, and the LED is OFF when the pull-up is set to OFF, that simple it is.

I think, this method is usable for all PIC devices which allows to individual pull-up switching on MCLR pin.

[Dave]

As a point of reference:


PICAXE Chip Type Label on Chip (DIP) Label on Chip (SM) Advanced Technical Details
PICAXE-08M2 PICAXE-08M2+ 12F1840 Microchip Datasheet
PICAXE-14M2 PICAXE-14M2 PIC16F1825 Microchip Datasheet
PICAXE-18M2 PICAXE-18M2+ PIC16F1847 Microchip Datasheet
PICAXE-20M2 PICAXE-20M2 PIC16F1829 Microchip Datasheet
PICAXE-20X2 PIC18F14K22 PIC18F14K22 Microchip Datasheet
PICAXE-28X2 PIC18F25K22 PIC18F25K22 Microchip Datasheet
PICAXE-40X2 PIC18F45K22 PIC18F45K22 Microchip Datasheet

[mpgmike]

Louislouis, that was some impressive "thinking outside the box". Well done!