|
Kategorie: Diplomové, bakalářské práce |
Tento dokument chci!
Práce popisuje principy a problémy při realizaci ultrazvukového anemometru. Je popsán princip výpočtu rychlosti větru a následné korekce výpočtu. Pro realizaci jsou využity ultrazvukové sensory a microcontrolér ARM Cortex-M3. Práce se zabývá generováním PWM signálu, jeho analogovou filtrací, zesílením a odvysíláním. Na přijímací straně jeto nízkonapěťový zesilovač a komparátor. Vyvíjený kód je popsán pomocí vývojového diagramu.
first line the display printed
application name. Therefore input argument first field captured ADC sequence.4. we
received signal, third condition fulfilled. Then
adc_ppx_aver and adc_ppy_aver are used for averaging actual adc_pp value. It
means that signal was received, it’s triggered timer_post_int function. Second condition fulfilled after timer interrupt.
Functions inside third condition serve measure received signal and calculate
wind speed. With first condition pwm_prepare function called. Otherwise set flag measure
again with X_PWM Y_PWM state. When flag doesn’t fulfill any condition,
program waiting interrupt. As
input argument are adc_pp variable and addresses adc_ppx_aver, adc_ppy and
i variables. Here
starts measurement axis.
Forth conditions tests flag measurement results are convenient add actual
measured time wind speed calculation. Here flag variable tested. see adc_pp averaged value from last ADC sequences. For
calculation ADC sequence peak peak value, adc_pp takes place. Addresses of
tx_array and ty_array are given count time values first position array and
keep last averages here.3 Main function
Function start with local variable definitions.
Then gpio_post_int gives measured time and the time correct range, set
flag X_WIND_CALC Y_WIND_CALC state. Then temp
variable adjust airspeed constant actual temperature condition. The function called with address first field adc_array. The
temp variable serve for temperature measurement. first level
there are conditions.
In adc_peaktopeak function calculated ADC peak peak value stored
sequence. Address and variables let know number order this
function. first adc_sample function stored captured ADC samples adc_array
field.
The last what can measured temperature.
Program continues infinite while loop.
Program continue with display initialization.4. used capture time from timer,
tx_array and ty_array are used buffer time averages from measurements before. Then function adc_pp_average called inform
us about adc_pp value. With 32th calling this function, new wind
speed value calculated. The
function returns actual adc_pp value. The last variables are and
serve for counting cycles. Input arguments are with actual measured time, adc_pp for
time correction based peak peak ADC value received signal. don’t measure every cycle we
measure when wind speed for axis was updated. that moment variable equal to
23
. After that initialization functions are called
