Getting Started

Chapter 11 The Butterfly

Chapter 11 The Butterfly L

LCD

CD

n all the little black bugs to run around

nd align themselves in such peculiar patterns. And that’s the extent of the detail

of LCDs. We’ll concentrate instead on

sing C to train the little black bugs to do our tricks. If you must know the magic,

application note: AVR065: LCD Driver for the STK502 and

even more intact we will begin by using software based on

ftwar on http://w i.a ni-

I read a book (I think it was David Brin’s ‘Practice Effect’) where some primitive
people found a digital watch with an LCD display. They were amazed that
whoever made the thing was able to trai
a
I’ll give on the underlying technology
u
then Atmel has an
AVR Butterfly available from their website that will get you deep into the gory
details. And the Atmega169 data book has a nice chapter ‘LCD Controller’ that is
a sure cure for insomnia.

To keep our ignorance
the LCD-Test so e available ww.siwaw rubi.u
kl.de/avr_projects/#bf_app n in.c file begins with the confidence

debu - may not work

ang me shoehorning it all into a demonstrator

it works just fin We use these func ons w thout attem to

nd them. Another way to say this is that we will enhance our productivity

ec orient principle not

unctions at our disposal in LCD_functions module:

LCD_putc(uint8 character

rites a character to the LCD digit

ar har scrollmode)

a string CD

o *pStr is a pointer to the string

o scrollmode is not used

id LCD_puts_f(con *pFlashStr, char scrollm ;

the L ring stored in fl

o *pFlashStr is a pointer to the flash string

oting that the ma
building:

// mt - used for gging only

However, with a few ch es and so
module,
ndersta

e. ti i pting
u
by reusing existing code
llowing ourselves to mess with perfectly good software.

and conform to obj t ed s by
a

F

• void _t digit, char );
  o W


• void LCD_puts(ch *pStr, c ;
  o Writes to the L


• vo st char ode)
  o Writes to CD a st ash