;
; Displaying LCD and LED + to make it read temprature
;
; read and send temperature
;
; Neil Gershenfeld
; CBA MIT 10/25/07
;
; (c) Massachusetts Institute of Technology 2007
; Permission granted for experimental and personal use;
; license for commercial sale available from MIT.
;
;BEKY Tried to modify the MIT code.
;We will see on the next episode
;
.include “tn44def.inc”
;
; definitions
;
.equ red = PB0; red pin
.equ green = PB1; green pin
.equ blue = PB2; blue pin
;
; registers
;
.def temp = R16; temporary storage
.def temp1 = R17; temporary storage
.def count = R17; loop counter
.def pwm = R18; PWM counter
;
; code segment
;
.cseg
.org 0
rjmp reset
;
; main program
;
;
.equ DB7 = PA0
.equ DB6 = PA1
.equ DB5 = PA2
.equ DB4 = PA3
.equ E = PA4
.equ RS = PA5
;
; registers
;
.def lcdbyte = R16
.def temp2 = R20
.def temp3 = R21
;
; code segment
;
;
; long_delay
; delay before redraw
;
.equ long_delay_time = 100
long_delay:
ldi temp1, long_delay_time
long_delay1:
ldi temp2, long_delay_time
long_delay2:
ldi temp3, long_delay_time
long_delay3:
dec temp3
brne long_delay3
dec temp2
brne long_delay2
dec temp1
brne long_delay1
ret
;
; lcd_delay
; delay between commands
;
.equ lcd_delay_time = 100
lcd_delay:
ldi temp1, lcd_delay_time
lcd_delay1:
ldi temp2, lcd_delay_time
lcd_delay2:
dec temp2
brne lcd_delay2
dec temp1
brne lcd_delay1
ret
;
; lcd_putchar
; put character in lcdbyte
;
lcd_putchar:
;
; set RS for data
;
sbi PORTA, RS
;
; output high nibble
;
cbi PORTA, DB7
sbrc lcdbyte, 7
sbi PORTA, DB7
cbi PORTA, DB6
sbrc lcdbyte, 6
sbi PORTA, DB6
cbi PORTA, DB5
sbrc lcdbyte, 5
sbi PORTA, DB5
cbi PORTA, DB4
sbrc lcdbyte, 4
sbi PORTA, DB4
;
; strobe E
;
nop
sbi PORTA, E
nop
cbi PORTA, E
;
; wait
;
rcall lcd_delay ; can be shorter
;
; output low nibble
;
cbi PORTA, DB7
sbrc lcdbyte, 3
sbi PORTA, DB7
cbi PORTA, DB6
sbrc lcdbyte, 2
sbi PORTA, DB6
cbi PORTA, DB5
sbrc lcdbyte, 1
sbi PORTA, DB5
cbi PORTA, DB4
sbrc lcdbyte, 0
sbi PORTA, DB4
;
; strobe E
;
nop
sbi PORTA, E
nop
cbi PORTA, E
;
; wait and return
;
rcall lcd_delay ; can be shorter
ret
;
; lcd_putcmd
; put command in lcdbyte
;
lcd_putcmd:
;
; clear RS for command
;
cbi PORTA, RS
;
; output command bits
;
out PORTA, lcdbyte
;
; strobe E
;
nop
sbi PORTA, E
nop
cbi PORTA, E
;
; wait and return
;
rcall lcd_delay
ret
;
; lcd_init
; initialize the LCD
;
lcd_init:
;
; power-up delay
;
rcall lcd_delay
;
; initialization sequence
;
ldi lcdbyte, (1 << DB5) + (1 << DB4)
rcall lcd_putcmd
ldi lcdbyte, (1 << DB5) + (1 << DB4)
rcall lcd_putcmd
ldi lcdbyte, (1 << DB5) + (1 << DB4)
rcall lcd_putcmd
;
; 4-bit interface
;
ldi lcdbyte, (1 << DB5)
rcall lcd_putcmd
;
; two lines, 5×7 font
;
ldi lcdbyte, (1 << DB5)
rcall lcd_putcmd
ldi lcdbyte, (1 << DB7)
rcall lcd_putcmd
;
; display on
;
clr lcdbyte
rcall lcd_putcmd
ldi lcdbyte, (1 << DB7) + (1 << DB6) + (1 << DB5)
rcall lcd_putcmd
;
; entry mode
;
clr lcdbyte
rcall lcd_putcmd
ldi lcdbyte, (1 << DB6) + (1 << DB5)
rcall lcd_putcmd
ret
;
; lcd_print
; print a null-terminated string
;
lcd_print:
lcd_print_loop:
lpm
mov lcdbyte, R0
cpi lcdbyte, 0
breq return
rcall lcd_putchar
adiw zl, 1
rjmp lcd_print_loop
return:
ret
;
; strings to print
;
line_1:
.db “Holla to”,0
line_2:
.db “fab labs!!”,0
;
; reset routine
;
reset:
;
; set clock divider to /8
;
;ldi temp, (1 << CLKPCE)
;ldi temp1, (0 << CLKPS3) | (0 << CLKPS2) | (1 << CLKPS1) | (1 << CLKPS0)
;out CLKPR, temp
;out CLKPR, temp1
;
; set stack pointer to top of RAM
;
ldi temp, high(RAMEND)
out SPH, temp
ldi temp, low(RAMEND)
out SPL, temp
;
; init LED pins for output
;
sbi PORTB, red
sbi DDRB, red
sbi PORTB, green
sbi DDRB, green
sbi PORTB, blue
sbi DDRB, blue
;
; set stack pointer to top of RAM
;
ldi temp, high(RAMEND)
out SPH, temp
ldi temp, low(RAMEND)
out SPL, temp
;
; init I/O pins
;
cbi PORTA, DB7
sbi DDRA, DB7
cbi PORTA, DB6
sbi DDRA, DB6
cbi PORTA, DB5
sbi DDRA, DB5
cbi PORTA, DB4
sbi DDRA, DB4
cbi PORTA, E
sbi DDRA, E
cbi PORTA, RS
sbi DDRA, RS
;
; init LCD
;
rcall lcd_init
;
; ldi count, 255
off_red_loop:
mov pwm, count
sbi PORTB, red
off_red_loop_off:
dec pwm
brne off_red_loop_off
mov pwm, count
cbi PORTB, red
off_red_loop_on:
inc pwm
brne off_red_loop_on
dec count
brne off_red_loop
ldi count, 255
red_green_loop:
mov pwm, count
cbi PORTB, red
sbi PORTB, green
red_green_loop_off:
dec pwm
brne red_green_loop_off
mov pwm, count
sbi PORTB, red
cbi PORTB, green
red_green_loop_on:
inc pwm
brne red_green_loop_on
dec count
brne red_green_loop
green_blue_loop:
mov pwm, count
cbi PORTB, green
sbi PORTB, blue
green_blue_loop_off:
dec pwm
brne green_blue_loop_off
mov pwm, count
sbi PORTB, green
cbi PORTB, blue
green_blue_loop_on:
inc pwm
brne green_blue_loop_on
dec count
brne green_blue_loop
blue_on_loop:
mov pwm, count
sbi PORTB, red
sbi PORTB, green
blue_on_loop_off:
dec pwm
brne blue_on_loop_off
mov pwm, count
cbi PORTB, red
cbi PORTB, green
blue_on_loop_on:
inc pwm
brne blue_on_loop_on
dec count
brne blue_on_loop
on_off_loop:
mov pwm, count
cbi PORTB, red
cbi PORTB, green
cbi PORTB, blue
on_off_loop_off:
dec pwm
brne on_off_loop_off
mov pwm, count
sbi PORTB, red
sbi PORTB, green
; main loop
;
main:
;
; go to zero position
;
clr lcdbyte
rcall lcd_putcmd
ldi lcdbyte, (1 << DB5)
rcall lcd_putcmd
;
; print first line
;
ldi zl,low(line_1*2)
ldi zh,high(line_1*2)
rcall lcd_print
;
; move to second line
;
ldi lcdbyte, (1 << DB7) + (1 << DB6)
rcall lcd_putcmd
clr lcdbyte
rcall lcd_putcmd
;
; print second line
;
ldi zl,low(line_2*2)
ldi zh,high(line_2*2)
rcall lcd_print
;
; pause
;
rcall long_delay
;
; clear display
;
clr lcdbyte
rcall lcd_putcmd
ldi lcdbyte, (1 << DB4)
rcall lcd_putcmd
;
; repeat
;
rjmp main
