Software for the Led light with ATtiny13


;
; ***********************************
; *    Ledlight with an ATtiny13    *
; * (C)2012 by avr-asm-tutorial.net *
; ***********************************
;
.nolist
.include "tn13def.inc"
.list
;
; *******************
;   H A R D W A R E
; *******************
;
;          ____________
;         /            |
; RES o--|             |--o VCC
;        |     AT      |
;  S3 o--|             |--o S2/SCK
;        |    tiny     |
;  S4 o--|             |--o OUT/MISO
;        |     13      |
; GND o--|             |--o S1/MOSI
;        |_____________|
;
; Input port bits
.equ bS1In = 0
.equ bS2In = 2
.equ bS3In = 3
.equ bS4In = 4
;
; Output port bit
.equ bOut = 1
;
; *******************************
;  H O W   T H I N G S   W O R K
; *******************************
;
; Processor:
;   Operates with 1.2 Mcs/s clock
;   Default R/C oscillator dived by 8
;   Default fuse settings
; Timer 0:
;   Operates as fast PWM with TOP=15
;   System clock prescaled by 256
;   f(PWM) = 293 c/s
;   OC0B controls PWM ratio (0 .. 15)
;     OCR0B set by lower nibble of control byte
;     sets OC0B output on restart,
;     clears output on compare match
;   OC0A sets TOP and interrupts
; Timing of cycles:
;   Upper nibble of control byte sets number
;     of PWM cycles (16 to 256)
;   Results in times between 0.055 and 0.88 seconds
; Input switches:
;   S1: if set dims down LED by half current (PWM / 2)
;   S2: accelerates speed by 16 (cycle duration / 16)
;   S3, S4: selects program
;     00: LEDs on and off seven times
;     01: linear up and down of LEDs
;     02: sinewave-type LEDs
;     03: anything from 00 to 03 in sequence
;
; *********************
;   R E G I S T E R S
; *********************
;
; Free: R0..R14
.def rSreg = R15 ; for saving and restoring SREG
.def rmp = R16 ; multipurpose outside ints
.def rimp = R17 ; multipurpose inside ints
.def rCnt = R18 ; count register for PWM cycles
.def rC3 = R19 ; counter for cycles in all-mode
; Free: R20 .. R29
; Used: ZH:ZL as Pointer to table in flash
;
; *******************************************
;  R E S E T   A N D   I N T - V E C T O R S
; *******************************************
;
 rjmp main ; Reset vector
 reti ; INT0
 reti ; PCINT0
 rjmp Tc0Int ; TIM0_OVF
 reti ; EE_RDY
 reti ; ANA_COMP
 reti ; TIM0_COMPA
 reti ; TIM0_COMPB
 reti ; WDT
 reti ; ADC
;
; Interrupt vector TIM0_OVF
;
Tc0Int:
 in rSreg,SREG ; save SREG
 dec rCnt ; next PWM cycle
 brne Tc0IntRet ; if not zero, continue
 lpm rCnt,Z+ ; read from table in flash
 mov rimp,rCnt ; copy byte to rimp
 andi rimp,0x0F ; mask upper nibble
 sbis PINB,bS1In ; half intensity?
 lsr rimp ; half PWM cycle
 out OCR0B,rimp ; write to PWM compare
 andi rCnt,0xF0 ; mask lower nibble
 sbis PINB,bS2In ; double speed?
 swap rCnt ; 16 times faster
Tc0Int1:
 lpm rimp,Z ; read next table value
 tst rimp ; zero?
 brne Tc0IntRet ; not zero
 out SREG,rSreg ; restore SREG
 set ; set T-flag
 reti ; return from int 
Tc0IntRet:
 out SREG,rSreg ; restore SREG
 reti ; return from int
;
; *************************************
;  M A I N   P R O G R A M   S T A R T
; *************************************
;
Main:
 ; Init stack
 ldi rmp,LOW(RAMEND) ; RAMEND to SPL
 out SPL,rmp
 ; Init ports
 ldi rmp,1<<bOut ; Output port as output
 out DDRB,rmp
 ldi rmp,0x1F-(1<<bOut) ; Switches pull-up, LEDs on
 out PORTB,rmp
 ; init Z-Pointer
 ldi ZH,HIGH(2*Tab1) ; Point Z to Tab1
 ldi ZL,LOW(2*Tab1)
 ldi rCnt,1 ; counter stage 1
 ; init Timer 0, Fast PWM, COMPB as positive PWM 
 ldi rmp,0x0F ; Compare A sets TOP
 out OCR0A,rmp
 ldi rmp,0x00 ; Compare B to LED off
 out OCR0B,rmp
 ldi rmp,(1<<COM0B1)|(1<<WGM01)|(1<<WGM00) ; Fast PWM
 out TCCR0A,rmp
 ldi rmp,(1<<WGM02)|(1<<CS02) ; Presc=256
 out TCCR0B,rmp
 ldi rmp,1<<TOIE0 ; int on TOP
 out TIMSK0,rmp
 ; init sleep and interrupts
 ldi rmp,1<<SE ; enable sleep mode idle
 out MCUCR,rmp
 sei ; enable interrupts
;
; *******************
;  M A I N   L O O P
; *******************
;
Loop:
 sleep ; go to sleep
 nop
 brtc Loop ; nothing to do, go to sleep again
 clt ; clear flag
 in rmp,PINB ; read switches
 andi rmp,0x18 ; mask all switches other than S3+S4
 brne Loop2
 ; program is 4
 inc rC3
 inc rC3
 cpi rC3,7 ; beyound limit
 brcs Loop1
 clr rC3
Loop1:
 ldi ZH,HIGH(2*TabPtr) ; point to pointer table
 ldi ZL,LOW(2*TabPtr)
 add ZL,rC3 ; add displacement
 ldi rmp,0 ; MSB correct? 
 adc ZH,rmp
 lpm rmp,Z+ ; Read table address
 lpm ZH,Z
 mov ZL,rmp
 rjmp Loop
Loop2: ; read switches
 lsr rmp ; divide by 2
 lsr rmp ; divide by 4
 ldi ZH,HIGH(2*TabPtr) ; pointer to pointer table
 ldi ZL,LOW(2*TabPtr)
 add ZL,rmp ; add displacement
 ldi rmp,0 ; MSB correct?
 adc ZH,rmp
 lpm rmp,Z+
 lpm ZH,Z
 mov ZL,rmp
 rjmp Loop
;
; Table pointers
;
TabPtr: 
 .dw 2*Tab1 ; program 4, start with program 1
 .dw 2*Tab3 ; dto., program 3
 .dw 2*Tab2 ; dto., program 2
 .dw 2*Tab1 ; point to table of program 1
;
; Tables for programs
;
Tab1:
 .dw 0xFFF0 ; off and on
 .dw 0xFFF0
 .dw 0xFFF0
 .dw 0xFFF0
 .dw 0xFFF0
 .dw 0xFFF0
 .dw 0xFFF0
 .dw 0xFFF0
 .dw 0xFFF0
 .dw 0x0000 ; end
Tab2: ; Modulated Up/Down
 .dw 0xA0C1
 .dw 0xA1C2
 .dw 0xA2C3
 .dw 0xA3C4
 .dw 0xA4C5
 .dw 0xA5C6
 .dw 0xA6C7
 .dw 0xA7C8
 .dw 0xA8C9
 .dw 0xA9CA
 .dw 0xAACB
 .dw 0xABCC
 .dw 0xACCD
 .dw 0xADCE
 .dw 0xAECF
 .dw 0xAFCE
 .dw 0xAECD
 .dw 0xADCC
 .dw 0xACCB
 .dw 0xABCA
 .dw 0xAAC9
 .dw 0xA9C8
 .dw 0xA8C7
 .dw 0xA7C6
 .dw 0xA6C5
 .dw 0xA5C4
 .dw 0xA4C3
 .dw 0xA3C2
 .dw 0xA2C1
 .dw 0xA1C0
 .dw 0xA0C1
 .dw 0xA1C2
 .dw 0xA2C3
 .dw 0xA3C4
 .dw 0xA4C5
 .dw 0xA5C6
 .dw 0xA6C7
 .dw 0xA7C8
 .dw 0xA8C9
 .dw 0xA9CA
 .dw 0xAACB
 .dw 0xABCC
 .dw 0xACCD
 .dw 0xADCE
 .dw 0xAECF
 .dw 0xAFCE
 .dw 0xAECD
 .dw 0xADCC
 .dw 0xACCB
 .dw 0xABCA
 .dw 0xAAC9
 .dw 0xA9C8
 .dw 0xA8C7
 .dw 0xA7C6
 .dw 0xA6C5
 .dw 0xA5C4
 .dw 0xA4C3
 .dw 0xA3C2
 .dw 0xA2C1
 .dw 0xA1C0
 .dw 0x0000
Tab3:
 .dw 0xC1C0 ; linear up/down
 .dw 0xC3C2
 .dw 0xC5C4
 .dw 0xC7C6
 .dw 0xC9C8
 .dw 0xCBCA
 .dw 0xCDCC
 .dw 0xCFCE
 .dw 0xCDCE
 .dw 0xCBCC
 .dw 0xC9CA
 .dw 0xC7C8
 .dw 0xC5C6
 .dw 0xC3C4
 .dw 0xC1C2
 .dw 0xC1C0 ; restart
 .dw 0xC3C2
 .dw 0xC5C4
 .dw 0xC7C6
 .dw 0xC9C8
 .dw 0xCBCA
 .dw 0xCDCC
 .dw 0xCFCE
 .dw 0xCDCE
 .dw 0xCBCC
 .dw 0xC9CA
 .dw 0xC7C8
 .dw 0xC5C6
 .dw 0xC3C4
 .dw 0xC1C2
 .dw 0x00C0
TabEnd:
;
; End of source code
;
.db "(C)2012 by Gerhard Schmidt",0x00,0x00
.db "C(2)10 2ybG reahdrS hcimtd",0x00,0x00