Type:
Compiler/Assembler:
; Program for attiny13A PRESSURE GUAGE with Hitachi 1602LCD and I2C back pack
; uses pressure sensor from 0-200 psi range
; PB0: SDA, PB1: SCL, PB2:A/D input or pressure sensor connection
;connect Attiny13 PB0 to LCD SDA, Attiny13 PB1 to SCL . Both PB1 & PB0 should be connected to positive via 5K resistor individually as required by I2C bus . Pressure sensor signal connected ;to PB1. Compile with Atmel studio7 and burn HEX with USB ASP clone. AVRDUDESS is a good GUI based program ,
;thanks for danni from AVR freaks for the binary to ASCII routine
;Thanks to Kodera2t for I2C routine
;thanks to Donald Weiman (weimandn@alfredstate.edu) for delay routines
;
.equ fclk = 1000000 ; system clock frequency (for delays)
.DEF ANSL = R0 ;To hold low-byte of answer
.DEF ANSH = R1 ;To hold high-byte of answer
.DEF A = R12 ;To hold multiplicand
.DEF B = R11 ;To hold multiplier
.DEF C = R10 ;To hold bit counter
.def D = R9
.DEF nibble1 = R25 ;register to store data nibble
.DEF command1 = R22
.DEF command2 = R23
.DEF command3 = R24
.DEF command4 = R15
.DEF command5 = R14
.DEF command6 = R13
.DEF loader = R26
.def temp = R19
.def data = R16
.def cnt = R17
.def cnt2 = R18
.def display = R25
.def temp1 = R20
.def temp2 = R21
.def free1 = R9
.def free2 = R8
.equ count_start = 0x04
.equ count_end = 0x01
.equ subnum = 0x01
.equ SUB_COUNT = 0x04
.equ long_delay =0xFF
.equ data_command1 = 0b00001001 ; data control nibble ,led on P3, EN 0 on P2, R/W 0 (write) in P1 , RS 1 (0 instruction, 1 data) = 1001 =0x09
.equ data_command2 = 0b00001101 ; data control nibble , 1101 = 0x0D - EN goes hi=1
.equ data_command3 = 0b11111011 ; data control nibble , 1001 = 0x09 - EN goes low=0
.equ inst_command1 = 0b00001000 ;instruction control nibble , led on en-lo,Rw-0,rs =0 = 1000 = 0x08
.equ inst_command2 = 0b00001100 ;instruction control nibble , led on,EN hi , rs/RW 0 = 1100 = 0x0C
.equ inst_command3 = 0b11111011 ;instruction control nibble , led on, EN lo ,rs/rw 0 = 1000 = 0x08
.equ slave_address = 0b01001110 ;0x4E
; PB0: SDA, PB1: SCL, PB2:A/D input
setup:
; Init stack for subroutines
ldi display,LOW(RAMEND) ; Init stack
out SPL,display ; to stack pointer
ldi command1,inst_command1 ;lower nibble is I2c command led on en,Rw,rs =0
ldi command2,inst_command2 ;lower nibble led on,EN hi , rs/RW 0
ldi command3,inst_command3 ;loer nibble led on, EN lo ,rs/rw 0
ldi loader,data_command1
mov command4,loader
ldi loader,data_command2
mov command5,loader
ldi loader,data_command3
mov command6,loader
; delay timer for upto 65 seconds (for main loop operations)----- use command "rcall delayYx1mS" for delay as per enetred value in the brakets in millisecs.
;ldi YL, low(1000) ;enter desired milliseconds(ms) for the delay needed in the (.......),used for delay in the range of seconds
;ldi YH, high(1000) ;enter desired milliseconds(ms) for the delay needed in the (.......),used for delay in the range of seconds
; PB0 (SDA) and PB1 (SCL) are tristated for hi and DDR is changed to output for low on I2C bus
ldi temp1, 0b00
out DDRB, temp1 ;pb0 & pb1 is now input
out portb,temp1 ;pb0 & pb1 is now tristated , both i2c lines are pulled up by ext resitors to hi
; initially, SDA and SCL are high
rcall lcd_init ; LCD initialize as per hitachi data sheet HD44780
; starting A/D converter, free running mode
ldi temp1, ((1<<ADEN)+(1<<ADSC)+(1<<ADATE)+(1<<ADIE)+(0<<ADIF)+(1<<ADPS2)+(0<<ADPS1)+(1<<ADPS2))
out ADCSRA,temp1
ldi temp1, 0x00
out ADCSRB, temp1
; selecting PB2 for A/D input
ldi temp1, (1<<MUX1)+(0<<MUX0)+(1<<ADLAR) ; adc2,PB4 , adc result left adjusted
out ADMUX,temp1
ldi temp1, 1<<ADC2D
out DIDR0, temp1
ldi temp ,5
rcall delayTx1uS
; reading A/D result in free1
in free1,ADCL
in free2,ADCH
mov loader, free2
push data
push cnt
push cnt2
push temp
push temp1
;3. MANUALLY MULTIPLYING TWO SINGLE-BYTE NUMBERS
;To do standard multiplication we examine how binary multiplication is achieved, we notice that when a digit in the multiplier is a one we add a shifted version of the multiplicand to our result. When the multiplier digit is a zero we need to add zero, which means we do nothing.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;The routine below mimics the hardware multiply (MUL) by leaving the multiplicand and multiplier untouched, and the result appears in the register pair R1 and R0. It shifts the bits of the multiplier into the carry bit and uses the contents of the carry to add the multiplicand if it is a one or skip it if the carry is a zero. The routine takes about sixty cycles.
;.DEF ANSL = r16 data ;To hold low-byte of answer
;.DEF ANSH = R17 cnt ;To hold high-byte of answer
;.DEF A = R18 cnt2 ;To hold multiplicand
;.DEF B = R19 temp ;To hold multiplier
;.DEF C = R20 temp1 ;To hold bit counter
MOV cnt2,loader ;Load multiplicand into A
LDI temp,79
;MOV temp,loader ;Load multiplier into B ((5/255)* (200psi/5V) = 0.788 psi / ADC count)
MUL8x8:
LDI temp1,8
;MOV temp1,loader ;Load bit counter into C
CLR cnt ;Clear high-byte of answer
MOV data,temp ;Copy multiplier into low-byte of answer
LSR data ;Shift low-bit of multiplier into Carry
LOOP: BRCC SKIP ;If carry is zero then skip addition
ADD cnt,cnt2 ;Add multiplicand to answer
SKIP: ROR cnt ;Shift low-bit of high-byte
ROR data ;of answer into low-byte
DEC temp1 ;Decrement bit-counter
BRNE LOOP ;Check if done all eight bits
;Result left in ANSL and ANSH
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;.def a0 = r0 = ANSL = 16 ,data
;.def a1 = r1 = ANSH =17,cnt
;.def a2 = r12 = A =18 , cnt2
;.def a3 = r11 = B =19 ,temp
;.def a4 = r10 = C =20, temp1
;************************************************************************
;* *
;* binary to ASCII decimal conversion *
;* *
;************************************************************************
;input: a1, a0 = 16 bit value 0 ... 65535
;output: a4, a3, a2, a1, a0 = digits
;cycle: 27 .. 183
;bytes: 42
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
binbcd:
ldi temp1,-1 + '0'
;mov temp1, loader ;0x2F = -1 decimal + ascii 0 (decimal 48 or 0x30) decimal 47 or 0x2F
_bib1: inc temp1 ; times operation done
subi data, low(10000)
sbci cnt, high(10000) ; if carry flag set
brcc _bib1 ; branch if carry flag clear till-ve operation (original value less than 10000)
ldi temp,10 + '0'
;mov B, loader ;0x3A , 10 decimal + ascii 0=46 in hex a+30 =3A = decimal 58
_bib2: dec temp ; decrease one count from 58 to reach 48
subi data, low(-1000) ; subtract with -1000 decimal (adds 1000)
sbci cnt, high(-1000) ; adds 1000 till carry is set
brcs _bib2 ; branch if carry set
ldi cnt2, -1 + '0'
;mov A, loader ;0x2F = -1 decimal + ascii 0 (decimal 48 or 0x30) decimal 47 or 0x2F
_bib3: inc cnt2 ;times operation done
subi data, low(100) ;
sbci cnt, high(100) ;subtract 100 till carry flag is set indicating negative number
brcc _bib3 ;branch if carry flag clear
ldi cnt, 10 + '0'
;mov ANSH, loader ;0x3A , 10 decimal + ascii 0=46 in hex a+30 =3A = decimal 58
_bib4: dec cnt
subi data, -10
brcs _bib4
subi data, -'0'
; ret
mov r0,data ; unit
mov r1,cnt ; ten
mov r2,cnt2 ; hundred
mov r3,temp ; thousand
mov r4,temp1; tenthousand
pop temp1
pop temp
pop cnt2
pop cnt
pop data
ldi loader,0b11000000 ;0b1100_000 ; (0xC0) second line,first digit ,DDRAM address as per data sheet is 0x47 (1000000)+ 10000000 is the DDRAM control code = 0b11000000
mov nibble1,loader ;loads info in loader to nibble register for AND,OR,SWAP etc to write data
rcall nibble_write_instruction ;calls LCD instruction/command write subroutine
mov loader,r4 ;10000 position ASCII value
mov nibble1,loader
rcall nibble_write_data ;calls LCD data write subroutine
mov loader,r3 ;1000 position ASCII value
mov nibble1,loader
rcall nibble_write_data
mov loader,r2 ;100 position ASCII value
mov nibble1,loader
rcall nibble_write_data
ldi loader,0b00111110 ;decimal symbol
mov nibble1,loader
rcall nibble_write_data
mov loader,r1 ;10 position ASCII value
mov nibble1,loader
rcall nibble_write_data
mov loader,r0 ;1 position ASCII value
mov nibble1,loader
rcall nibble_write_data
ldi loader,0b11001000 ;load DDRAM address C8 (8th position)
mov nibble1,loader
rcall nibble_write_instruction
ldi loader, 0b01010000 ;ASCII for P
mov nibble1,loader
rcall nibble_write_data
ldi loader,0b01010011 ;ASCII for S
mov nibble1,loader
rcall nibble_write_data
ldi loader,0b01001001 ;ASCII for I
mov nibble1,loader
rcall nibble_write_data
start:
ldi temp1, 0b01 ;scl 1 , sda 0
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b11 ;scl 0 , sda 0
out ddrb, temp1
rcall delay10uS
ret
;cl, da
ends:
ldi temp1,0b11 ;both scl & sda pulled low so as next step ensures a low to hi transition of SDA for stop
out ddrb, temp1 ; scl 0 , sda 0
rcall delay10uS
ldi temp1,0b01 ;scl 1 ,sda 0
out ddrb, temp1 ;while scl is hi ,sda is low , next step sda will go hi creating a stop condition
rcall delay10uS
ldi temp1,0b00 ;scl 1 . sda 1
out ddrb, temp1 ;sda reached hi from low in the previous step
rcall delay10uS
ret
init:
ldi temp1, 0b00 ;
out ddrb,temp1 ; data direction set as input = SCL & SDA now hi
out PORTB, temp1 ; ports also loaded with 0 , Zstate
rcall delay10uS
ret
;cl da
bit_high:
ldi temp1, 0b11 ; scl 0 ,sda 0
out ddrb, temp1 ; writing 1 to ddr will make it output and alreday port is 0 so SDA & SCL is pulled low
rcall delay10uS
ldi temp1, 0b10 ; scl 0 ,sda 1
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b00 ;scl 1 , sda 1
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b10 ; scl 0 , sda 1
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b11 ; scl 0 ,sda 0
out ddrb, temp1
rcall delay10uS
ret
;cl=1 da=0
bit_low:
ldi temp1, 0b11 ;scl 0 ,sda 0
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b11 ;scl 0 , sda 0
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b01 ; scl 1 , sda 0
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b11 ; scl 0 , sda 0
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b11 ; scl 0 , sda 0
out ddrb, temp1
rcall delay10uS
ret
;cl da
ack:
ldi temp1, 0b10 ; scl 0 , sda 1
out ddrb,temp1
;recheck:
;sbic pinb,pinb0 ; if pinb0 is 0 then slave ACKed
;rjmp recheck ; if pinb0 is 1 wait for ACK
rcall delay10uS
ldi temp1, 0b00 ; scl 1, sda 1 ( if ACK sda will become 0 when slave pulls low)
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b10
out ddrb, temp1
rcall delay10uS
ldi temp1, 0b11 ; scl 0 , sda 0
out ddrb, temp1
rcall delay10uS
ret
; writing data is stored in data
writedata:
ldi cnt,0x00
ldi cnt2,0x02
rep:
mov temp2, data
andi temp2,0b10000000
cpi temp2, 0b10000000
breq highbit
rcall bit_low
rjmp sendend
highbit:
rcall bit_high
sendend:
lsl data
inc cnt
cpi cnt,8
brne rep
ldi temp1, 0b10 ; scl 0 , sda 1 ( sda released for slave to send ACK)
out ddrb, temp1
ret
nibble_write_instruction:
rcall init
rcall start
ldi data,slave_address
rcall writedata
rcall ack
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command1
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader ;copies data for upper nibble operation
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command2
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader ;copies data for upper nibble operation
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
AND nibble1,command3
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader
swap nibble1 ;previous lower nibble is swapped to high nibble position
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command1
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader ;copies data for upper nibble operation
swap nibble1 ;previous lower nibble is swapped to high nibble position
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command2
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader
swap nibble1 ;previous lower nibble is swapped to high nibble position
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
AND nibble1,command3
mov data,nibble1
rcall writedata
rcall ack
rcall ends
ldi temp,20
rcall delayTx1mS
ret
nibble_write_data:
rcall init
rcall start
ldi data,slave_address
rcall writedata
rcall ack
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command4 ;adding the upper nibble and LCD commands as lower bits of the 8 bits in write data
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader ;copies data for upper nibble operation
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command5
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader ;copies data for upper nibble operation
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
AND nibble1,command6
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader
swap nibble1 ;previous lower nibble is swapped to high nibble position
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command4
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader ;copies data for upper nibble operation
swap nibble1 ;previous lower nibble is swapped to high nibble position
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
OR nibble1,command5
mov data,nibble1
rcall writedata
rcall ack
mov nibble1,loader
swap nibble1 ;previous lower nibble is swapped to high nibble position
ANDi nibble1,0XF0 ;upper nibble is preserved in register nibble1
AND nibble1,command6
mov data,nibble1
rcall writedata
rcall ack
rcall ends
ldi temp,5
rcall delayTx1uS
ret
lcd_init:
ldi temp,50
rcall delayTx1mS ;50ms delay as part of startup
rcall init
rcall start
ldi data,slave_address ;0x27 and write bit =0x4E
rcall writedata ;writedata subroutine is called to command PCF8574T i2c chip only during initialization, any 4 bit LCD is done by instruction_write or data_write subroutine after initialisation
rcall ack
ldi data,0b00111100 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata ;writedata subroutine is called to command PCF8574T i2c chip only during initialization, any 4 bit LCD is done by instruction_write or data_write subroutine after initialisation
rcall ack
ldi data,0b00111000 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata ;writedata subroutine is called to command PCF8574T i2c chip only during initialization, any 4 bit LCD is done by instruction_write or data_write subroutine after initialisation
rcall ack
rcall ends
ldi temp,20 ; value loaded here (20) decides the number of milli seconds in the delay below
rcall delayTx1mS ;20 milli seconds delay, slightly above hitachi data sheet
rcall init
rcall start
ldi data,slave_address ;0x27 and write bit =0x4E
rcall writedata
rcall ack
ldi data,0b00111100 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata
rcall ack
ldi data,0b00111000 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata
rcall ack
rcall ends
ldi temp,20
rcall delayTx1mS ;20 milli seconds delay, slightly above hitachi data sheet
rcall init
rcall start
ldi data,slave_address ;0x27 and write bit =0x4E
rcall writedata ;writedata subroutine is called to command PCF8574T i2c chip only during initialization, any 4 bit LCD is done by instruction_write or data_write subroutine after initialisation
rcall ack
ldi data,0b00111100 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata
rcall ack
ldi data,0b00111000 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata
rcall ack
rcall ends
ldi temp,20
rcall delayTx1mS ;20 milli seconds delay, slightly above hitachi data sheet
rcall init
rcall start
ldi data,slave_address ;0x27 and write bit =0x4E
rcall writedata ;writedata subroutine is called to command PCF8574T i2c chip only during initialization , any 4 bit LCD is done by instruction_write or data_write subroutine
rcall ack
ldi data,0b00101100 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata ;writedata subroutine is called to command PCF8574T i2c chip only during initialization , any 4 bit LCD is done by instruction_write or data_write subroutine
rcall ack
ldi data,0b00101000 ;Function set LCD , high nibble 0011 & lower commands led = 1,EN,RW,RS all 0.
rcall writedata ;writedata subroutine is called to command PCF8574T i2c chip only , any 4 bit LCD is done by instruction_write or data_write subroutine
rcall ack
rcall ends
ldi temp,20
rcall delayTx1mS ;20 milli seconds delay, slightly above hitachi data sheet
ldi loader,0b00101000 ; (0x28 4 bit ,2 line ,5x7)Function set LCD ,
mov nibble1,loader ;loads info in loader to nibble register for AND,OR,SWAP etc to write data
rcall nibble_write_instruction ;calls LCD instruction/command write subroutine
ldi loader,0b00001110 ;Function set LCD , (0x0C ). DISPLAY ON
mov nibble1,loader ;loads info in loader to nibble register for AND,OR,SWAP etc to write data
rcall nibble_write_instruction ;calls LCD instruction/command write subroutine
ldi loader,0b00000110 ;Function set LCD (entry mode set 0x06), ENTRY MODE SET
mov nibble1,loader ;loads info in loader to nibble register for AND,OR,SWAP etc to write data
rcall nibble_write_instruction ;calls LCD instruction/command write subroutine
ldi loader,0b00000001 ;Function set LCD (clear display 0x01), CLEAR DISPLAY
mov nibble1,loader ;loads info in loader to nibble register for AND,OR,SWAP etc to write data
rcall nibble_write_instruction ;calls LCD instruction/command write subroutine
ret
; ============================== Time Delay Subroutines =====================
; Name: delayYx1mS
; Purpose: provide a delay of (YH:YL) x 1 mS
; Entry: (YH:YL) = delay data
; Exit: no parameters
; Notes: the 16-bit register provides for a delay of up to 65.535 Seconds
; requires delay1mS
delayYx1mS:
rcall delay1mS ; delay for 1 mS
sbiw YH:YL, 1 ; update the the delay counter
brne delayYx1mS ; counter is not zero
; arrive here when delay counter is zero (total delay period is finished)
ret
; ---------------------------------------------------------------------------
; Name: delayTx1mS
; Purpose: provide a delay of (temp) x 1 mS
; Entry: (temp) = delay data
; Exit: no parameters
; Notes: the 8-bit register provides for a delay of up to 255 mS
; requires delay1mS
delayTx1mS:
rcall delay1mS ; delay for 1 mS
dec temp ; update the delay counter
brne delayTx1mS ; counter is not zero
; arrive here when delay counter is zero (total delay period is finished)
ret
; ---------------------------------------------------------------------------
; Name: delay1mS
; Purpose: provide a delay of 1 mS
; Entry: no parameters
; Exit: no parameters
; Notes: chews up fclk/1000 clock cycles (including the 'call')
delay1mS:
push YL ; [2] preserve registers
push YH ; [2]
ldi YL, low(((fclk/1000)-18)/4) ; [1] delay counter (((fclk/1000)-18)/4)
ldi YH, high(((fclk/1000)-18)/4) ; [1] (((fclk/1000)-18)/4)
delay1mS_01:
sbiw YH:YL, 1 ; [2] update the the delay counter
brne delay1mS_01 ; [2] delay counter is not zero
; arrive here when delay counter is zero
pop YH ; [2] restore registers
pop YL ; [2]
ret ; [4]
; ---------------------------------------------------------------------------
; Name: delayTx1uS
; Purpose: provide a delay of (temp) x 1 uS with a 16 MHz clock frequency
; Entry: (temp) = delay data
; Exit: no parameters
; Notes: the 8-bit register provides for a delay of up to 255 uS
; requires delay1uS
delayTx1uS:
rcall delay10uS ; delay for 1 uS
dec temp ; decrement the delay counter
brne delayTx1uS ; counter is not zero
; arrive here when delay counter is zero (total delay period is finished)
ret
; ---------------------------------------------------------------------------
; Name: delay10uS
; Purpose: provide a delay of 1 uS with a 16 MHz clock frequency ;MODIFIED TO PROVIDE 10us with 1200000cs chip by Sajeev
; Entry: no parameters
; Exit: no parameters
; Notes: add another push/pop for 20 MHz clock frequency
delay10uS:
;push temp ; [2] these instructions do nothing except consume clock cycles
;pop temp ; [2]
;push temp ; [2]
;pop temp ; [2]
;ret ; [4]
nop
nop
nop
ret
; ============================== End of Time Delay Subroutines ==============