Electronic Projects and Design Blog: October 2013

Project 23 : Automatic Room Lighting System

PIR sensor

Project 22 : LED Dimmer Controller

Circuit setup

Close view

Video on demand

Project 21 : Scanning Array Unit

8-wire unipolar stepper motor

Early project setup

Early project test

Early video 1

Early video 2

Test setup

Testing video

Finished product

Finished video

Tut 17 : LCD Big Characters

Big characters

PBP Program

'program to display big characters (numbers) on LCD

DEFINE OSC 20

@ device hs_osc

DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2

TRISB = 0
TRISD = 0

nPos VAR BYTE

LCDOut $FE,$40,$01,$01,$01,$01,$01,$01,$01,$01 ' Cust Char #0
LCDOut $FE,$48,$1F,$11,$11,$11,$11,$11,$11,$11 ' Cust Char #1
LCDOut $FE,$50,$1F,$10,$10,$10,$10,$10,$10,$1F ' Cust Char #2
LCDOut $FE,$58,$01,$01,$01,$01,$01,$01,$01,$1F ' Cust Char #3
LCDOut $FE,$60,$1F,$11,$11,$11,$11,$11,$11,$1F ' Cust Char #4
LCDOut $FE,$68,$11,$11,$11,$11,$11,$11,$11,$1F ' Cust Char #5
LCDOut $FE,$70,$1F,$01,$01,$01,$01,$01,$01,$1F ' Cust Char #6
LCDOut $FE,$78,$1F,$01,$01,$01,$01,$01,$01,$01 ' Cust Char #7

Pause 500
LCDOut $FE,1

loop:
nPos = 0
GoSub Zero
nPos = 1
GoSub One
nPos = 2
GoSub Two
nPos = 3

Pause 2000
GoTo loop

Zero:
LCDOut $FE,$80+nPos,1
LCDOut $FE,$C0+nPos,5
Return
One:
LCDOut $FE,$80+nPos,0
LCDOut $FE,$C0+nPos,0
Return
Two:
LCDOut $FE,$80+nPos,7
LCDOut $FE,$C0+nPos,2
Return

Tut 16 : LCD Custom Characters

Most of the alpha numeric LCD like 16x2 character has ability to generate few custom characters. Custom characters on any 16x2 LCD provides the functionality of CGRAM (Character Generator RAM) where you can create your own characters for display. The codes for custom character generation using PIC16F877 microcontroller can be created using any custom character generator available in the internet. The custom character generation using PIC16F877 is in 8bit mode.

Custom characters on LCD

Battery character on LCD

We can program 8 custom characters when we are using 5x8 font in the LCD settings and we can program 4 custom characters when we are using 5x10 font in the LCD settings. The binary coding in the custom charactor generator can be written in HEX form as in PBP program below.

Custom character generator

PBP Program

'program to display some characters on LCD

DEFINE OSC 20

@ device hs_osc

DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 4
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 5
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2

TRISB = 0
TRISD = 0

LCDOUT $FE,$40,$00,$0A,$0A,$00,$11,$0E,$00,$00 ' Cust Char #0: happy smiley
LCDOUT $FE,$48,$0E,$15,$1B,$19,$1B,$15,$0E,$00 ' Cust Char #1: copyright
LCDOUT $FE,$50,$0E,$0E,$1F,$0E,$04,$00,$1F,$00 ' Cust Char #2: press

Pause 500

LCDOut $FE,1

Loop:

LCDOut $FE,$80+0,0

Pause 1000

LCDOut $FE,$80+1,1

Pause 1000

LCDOut $FE,$80+2,2

Pause 1000

GoTo loop