Comments on: Tutorial 2 – “Hello World” Program in Assembly Language

By: krlosjcc

krlosjcc — Wed, 15 Sep 2010 19:00:55 +0000

thanks to István Cserny and Valentin I got the code to work, otherwise I just got a LED turned on, here’s the complete code I’m using to get a blinkin’ led

#include P18F4550.INC

CONFIG WDT=OFF; disable watchdog timer
CONFIG MCLRE = ON; MCLEAR Pin on
CONFIG DEBUG = ON; Enable Debug Mode
CONFIG LVP = OFF; Low-Voltage programming disabled (necessary for debugging)
CONFIG FOSC = INTOSCIO_EC;Internal oscillator, port function on RA6

org 0; start code at 0

CBLOCK 0
Delay1:1
Delay2:1
ENDC

ORG 0

;Delay1 res 1 ;reserve 1 byte for the variable Delay1
;Delay2 res 1 ;reserve 1 byte for the variable Delay2

Start:
CLRF PORTD
CLRF TRISD
CLRF Delay1
CLRF Delay2

MainLoop:
BTG PORTD,RD1 ;Toggle PORT D PIN 1 (20)
Delay:
DECFSZ Delay1,1 ;Decrement Delay1 by 1, skip next instruction if Delay1 is 0
GOTO Delay
DECFSZ Delay2,1
GOTO Delay
GOTO MainLoop
end

By: Valentin

Valentin — Wed, 18 Aug 2010 18:52:52 +0000

Hey,

This is a very good tutorial but there were a couple of things that I needed to change before it compiled

change
#include 18f4550
to
#include P18F4550.INC

change

GOTO Delay DECFSZ Delay2,1

GOTO Delay
DECFSZ Delay2,1 ; yes the return made a difference

and don’t forget to mention that the build should be in relocatable code

By: Nephilyn Lee

Nephilyn Lee — Tue, 27 Jul 2010 10:40:26 +0000

Hi, very good tut I am new to pic micocontrollers but do program in Vb6/.Vb.net/C#(beginner level) as I find this stuff interesting. Once I get up to scratch with
the pic stuff I would like to interface a .net app to the picf4550 through usb, I have read that the picf4550 is a usb client device.

By: Shawn

Shawn — Wed, 24 Feb 2010 07:18:23 +0000

Thanks for the great tutorial, Andrey!
I’m just getting started with PIC controllers and I don’t think I would have been able to find a better “Getting-started” tutorial. This has really helped my frustration level go WAYYYY down.

By: Demolishun

Demolishun — Wed, 09 Dec 2009 03:30:40 +0000

This is such an awesome tutorial. I have programmed PIC16s and am now learning the PIC18. I needed a quick start for testing my setup to see how things are working. The ability to toggle an LED allows me to gauge how the oscillator is working by the output switching and giving me a value my freq counter can read.

Thanks for doing such a nice job!

By: Tutorial 4 - “Hello World” Program in C » PIC18F.COM - Tutorials and Sample Code

Mon, 16 Nov 2009 07:05:39 +0000

[...] the basics of PIC18F C programming and provide simple sample code for a blinking LED, similar to tutorial 2. If I receive positive feedback, more tutorials will follow. This tutorial assumes minimal [...]

By: István Cserny

István Cserny — Mon, 12 Oct 2009 06:16:57 +0000

Hi!

I would like to note that the data space reservation at the beginning of your program test2.asm is wrong. The MPASM compiler says: “No memory has been reserved by this instruction”. This will result in an infinite loop (instead of a finite delay) and the LED will not blink.

The correct code would be:
CBLOCK 0×00
Delay1:1
Delay2:1
ENDC

ORG 0×00
….

Best regards: I. Cserny

By: Jasper

Jasper — Thu, 25 Jun 2009 20:07:03 +0000

great site, short and understandable tutorials

By: angad

angad — Thu, 18 Jun 2009 14:08:39 +0000

THANK YOU SO MUCH… This was a godsend

By: vaclav

vaclav — Fri, 30 Jan 2009 11:46:03 +0000

You did not set BSR to 0x0f ? And it still works ? IMHO after RESET, BSR = 0×00. And all special registers like PORTD, TRISD etc. are on page 15. Can you explain it for me ? I programmed only 16F processors and they are a little bit different…