Mistakes that we made originally, we changed X min and Y min like we should do, but we also changed X width and Height. But we shouldn't have to change X width and Height.
Programming the board
Then I have to make program for the board.
I downloaded [AVR Data sheet for Attiny45] from Atmel
I take a look at codes from Fab Hello World page specially at hello.speaker.45.pwm.asm and hello.step.45.asm
Some AVR Instructions
SBI -> Set Bit in I/O Register
CBI -> Clear Bit in I/O Register
LDI -> Load Immediate
BRNE-> Branch if Not Equal
First we made some experiments
Open AVR studio
File New Project
Write .asm code
Build and Run
Step into
First we look at our board
We look at our hello.speaker.45.cad board and check if we have some available pins to use.
Define variablbe.
.equ sensor_pin = PB3 ; we call pin PB3 a sensor pin
.equ charge_pin = PB4 ; PB4 is our charge pin
.def sensor_value_high = R23 ; temporary storage for sensor value (here we store our sensor values (because we have 10 bit value, here we have the higher value)
.def sensor_value_low = R24 ; temporary storage for sensor value (here we store our sensor values (because we have 10 bit value, here we have the lower value)
; set Chargepin to output
;
cbi PORTB, charge_pin (the charge_pin is set to low)
sbi DDRB, charge_pin ( charge pin is output
Next we define measuring method.
; init A/D
;
cbi ADMUX, REFS2 ; use Vcc as reference
cbi ADMUX, REFS1 ; "
cbi ADMUX, REFS0 ; "
cbi ADMUX, ADLAR ; right-adjust result
cbi ADMUX, MUX3 ; set MUX to ADC2 (PB4) here we decide what pin we use for measurement
cbi ADMUX, MUX2 ; "
sbi ADMUX, MUX1 ; "
cbi ADMUX, MUX0 ; "
sbi ADCSRA, ADEN ; enable A/D
cbi ADCSRA, ADPS2 ; set prescaler to /2 (here we define at what speed we measure)
cbi ADCSRA, ADPS1 ; "
cbi ADCSRA, ADPS0 ; "
Mistakes that we made:
First we defined PB4 as a sensor pin and a charge pin, we fixed that by defining PB3 as a charge pin and PB4 as a sensor pin.
Then we started to get some response from the sensor.
At first we only used lower value.
;==First version==
;
; hello.speaker.45.pwm.asm
;
; software PWM speaker hello-world program
;
; Neil Gershenfeld MIT CBA 8/2/07
;
; (c) Massachusetts Institute of Technology 2007
; Permission granted for experimental and personal use;
; license for commercial sale available from MIT.
;
.include "tn45def.inc"
.equ mosfet_pin = PB1 ; MOSFET pin
.equ max_pwm = 20 ; maximum PWM on value
.equ pwm_length = 40 ; PWM loop length
.equ sensor_pin = PB4 ; we call pin PB4 a sensor pin
.equ charge_pin = PB3 ; PB3 is our charge pin
.def temp = R16 ; temporary storage
.def temp1 = R17 ; temporary storage
.def pwm = R18 ; PWM value
.def pwm_count = R19 ; PWM counter
.def pwm_cycle = R20 ; PWM cycle count
.def pwm_cycle_count = R21 ; number of PWM cycles per audio cycle
.def cycle_count = R22 ; audio cycle count
.def sensor_value_high = R23 ; temporary storage for sensor value
.def sensor_value_low = R24 ; temporary storage for sensor value
.cseg
.org 0
rjmp reset
;
; main program
;
reset:
;
; initialization
;
; set clock divider to /1
;
ldi temp, (1 << CLKPCE)
ldi temp1, (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << 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
;
; set MOSFET to output
;
cbi PORTB, mosfet_pin
sbi DDRB, mosfet_pin
;
; set Chargepin to output
;
cbi PORTB, charge_pin
sbi DDRB, charge_pin
;
; init A/D
;
cbi ADMUX, REFS2 ; use Vcc as reference
cbi ADMUX, REFS1 ; "
cbi ADMUX, REFS0 ; "
cbi ADMUX, ADLAR ; right-adjust result
cbi ADMUX, MUX3 ; set MUX to ADC2 (PB4) here we decide what pin we use for measurement
cbi ADMUX, MUX2 ; "
sbi ADMUX, MUX1 ; "
cbi ADMUX, MUX0 ; "
sbi ADCSRA, ADEN ; enable A/D
cbi ADCSRA, ADPS2 ; set prescaler to /2 (here we define at what speed we measure)
cbi ADCSRA, ADPS1 ; "
cbi ADCSRA, ADPS0 ; "
; infinite main loop
;
main_loop:
;first we fetch one measurement
; read response
;
sbi ADCSRA, ADSC ; start conversion
adloopup:
sbic ADCSRA, ADSC ; loop until complete
rjmp adloopup
;
; save conversion
;
in sensor_value_low, ADCL ; get low byte from sensor
in sensor_value_high, ADCH ; get high byte from sensor
ldi pwm_cycle_count, 5
frequency_loop:
; we will not use this line ldi cycle_count, sensor_value_low
mov cycle_count, sensor_value_low
cycle_count_loop:
ldi pwm, max_pwm
cycle_loop:
mov pwm_cycle, pwm_cycle_count
pwm_loop:
mov pwm_count, pwm
sbi PORTB, mosfet_pin
pwm_on_loop:
dec pwm_count
brne pwm_on_loop
ldi pwm_count, pwm_length
sub pwm_count, pwm
cbi PORTB, mosfet_pin
pwm_off_loop:
dec pwm_count
brne pwm_off_loop
dec pwm_cycle
brne pwm_loop
dec pwm
brne cycle_loop
dec cycle_count
brne cycle_count_loop
dec pwm_cycle_count
brne frequency_loop
rjmp main_loop
Code of second version
This is second version of our program and now it changes the speed of the music depending on how we turn the variable resistor.
;
; hello.speaker.45.pwm.asm
;
; software PWM speaker hello-world program
;
; Neil Gershenfeld MIT CBA 8/2/07
;
; (c) Massachusetts Institute of Technology 2007
; Permission granted for experimental and personal use;
; license for commercial sale available from MIT.
; changed by Fab Academy students in Vestmannaeyjar
.include "tn45def.inc"
.equ mosfet_pin = PB1 ; MOSFET pin
.equ max_pwm = 20 ; maximum PWM on value
.equ pwm_length = 40 ; PWM loop length
.equ sensor_pin = PB4 ; we call pin PB4 a sensor pin
.equ charge_pin = PB3 ; PB3 is our charge pin
.def temp = R16 ; temporary storage
.def temp1 = R17 ; temporary storage
.def pwm = R18 ; PWM value
.def pwm_count = R19 ; PWM counter
.def pwm_cycle = R20 ; PWM cycle count
.def pwm_cycle_count = R21 ; number of PWM cycles per audio cycle
.def cycle_count = R22 ; audio cycle count
.def sensor_value_high = R23 ; temporary storage for sensor value
.def sensor_value_low = R24 ; temporary storage for sensor value
.DEF rd1l = R0 ; LSB 16-bit-number to be divided
.DEF rd1h = R1 ; MSB 16-bit-number to be divided
.DEF rd1u = R2 ; interim register
.DEF rd2 = R3 ; 8-bit-number to divide with
.DEF rel = R4 ; LSB result
.DEF reh = R5 ; MSB result
.DEF rmp = R25; multipurpose register for loading
.cseg
.org 0
rjmp reset
;
; main program
;
reset:
;
; initialization
;
; set clock divider to /1
;
ldi temp, (1 << CLKPCE)
ldi temp1, (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << 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
;
; set MOSFET to output
;
cbi PORTB, mosfet_pin
sbi DDRB, mosfet_pin
;
; set Chargepin to output
;
cbi PORTB, charge_pin
sbi DDRB, charge_pin
;
; init A/D
;
cbi ADMUX, REFS2 ; use Vcc as reference
cbi ADMUX, REFS1 ; "
cbi ADMUX, REFS0 ; "
cbi ADMUX, ADLAR ; right-adjust result
cbi ADMUX, MUX3 ; set MUX to ADC2 (PB4) here we decide what pin we use for measurement
cbi ADMUX, MUX2 ; "
sbi ADMUX, MUX1 ; "
cbi ADMUX, MUX0 ; "
sbi ADCSRA, ADEN ; enable A/D
cbi ADCSRA, ADPS2 ; set prescaler to /2 (here we define at what speed we measure)
cbi ADCSRA, ADPS1 ; "
cbi ADCSRA, ADPS0 ; "
; infinite main loop
;
main_loop:
;first we fetch one measurement
; read response
;
sbi ADCSRA, ADSC ; start conversion
adloopup:
sbic ADCSRA, ADSC ; loop until complete
rjmp adloopup
;
; save conversion
;
in sensor_value_low, ADCL ; get low byte from sensor
in sensor_value_high, ADCH ; get high byte from sensor
;Here we divide the results from the sensor Devision starts
; Load the test numbers to the appropriate registers
;
mov rd1h,sensor_value_high ; use the high sensor value
mov rd1l,sensor_value_low ; use the low sensor value
ldi rmp,0x4 ; 0x4 to be divided with
mov rd2,rmp
;
; Divide rd1h:rd1l by rd2
;
div8:
clr rd1u ; clear interim register
clr reh ; clear result (the result registers
clr rel ; are also used to count to 16 for the
inc rel ; division steps, is set to 1 at start)
;
; Here the division loop starts
;
div8a:
clc ; clear carry-bit
rol rd1l ; rotate the next-upper bit of the number
rol rd1h ; to the interim register (multiply by 2)
rol rd1u
brcs div8b ; a one has rolled left, so subtract
cp rd1u,rd2 ; Division result 1 or 0?
brcs div8c ; jump over subtraction, if smaller
div8b:
sub rd1u,rd2; subtract number to divide with
sec ; set carry-bit, result is a 1
rjmp div8d ; jump to shift of the result bit
div8c:
clc ; clear carry-bit, resulting bit is a 0
div8d:
rol rel ; rotate carry-bit into result registers
rol reh
brcc div8a ; as long as zero rotate out of the result
; registers: go on with the division loop
; End of the division reached
ldi pwm_cycle_count, 5
frequency_loop:
; we will not use this line ldi cycle_count, sensor_value_low
mov cycle_count, rel ; we use the result from the devision, lower value
cycle_count_loop:
ldi pwm, max_pwm
cycle_loop:
mov pwm_cycle, pwm_cycle_count
pwm_loop:
mov pwm_count, pwm
sbi PORTB, mosfet_pin
pwm_on_loop:
dec pwm_count
brne pwm_on_loop
ldi pwm_count, pwm_length
sub pwm_count, pwm
cbi PORTB, mosfet_pin
pwm_off_loop:
dec pwm_count
brne pwm_off_loop
dec pwm_cycle
brne pwm_loop
dec pwm
brne cycle_loop
dec cycle_count
brne cycle_count_loop
dec pwm_cycle_count
brne frequency_loop
rjmp main_loop
Using AVR Studio
Build and Run
Create .hex file
Attention -> Remember to unplug the speaker before you program the micro controler.
