Implement a system to measure the distance with Ultrasonic sensor HC-SR04 using ATmega32 microcontroller,
Use ATmega32 Microcontroller with frequency 8Mhz.
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Measure the distance using the Ultrasonic sensor HC-SR04. Check the
HC-SR04 Ultrasonic Tutorialpdf file to understand how to interface with this sensor. -
The LCD should display the distance value like that:
- The project should be design and implemented based on the layered architecture model as follow:
| Software Layered Model | Driver Name |
|---|---|
| Application Layer (APP) | Application.c |
| Hardware Abstraction Layer (HAL) | LCD / ULTRASONIC |
| MicroController Abstraction Layer (MCAL) | GPIO / ICU |
- Once the calculations are done by the microcontroller according to the logic, the temperature is displayed on the LCD.
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ATmega32 microcontroller needs to transmit at least 10 us trigger pulse to the HC-SR04 Trigger Pin.
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After getting a trigger pulse, HC-SR04 automatically sends eight 40 kHz sound waves and the microcontroller waits for rising edge output at the Echo pin.
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When the rising edge capture occurs at the Echo pin which is connected to an input of ATmega32, Start Timer of ATmega32 and again wait for a falling edge on the Echo pin.
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As soon as the falling edge is captured at the Echo pin, the microcontroller reads the count of the Timer. This time count is used to calculate the distance to an object.
Note: Here we are using the Input Capture unit on PD6(ICP1) pin.
Calculation (distance in cm)
- Sound velocity = 340.00 m/s = 34000 cm/s
- As Signal travels from HCSR04 to object and returns to the module HCSR04
The distance of Object (in cm) = (340000 * Time)/2
= 17000 * Time
- As an internal 8MHz oscillator frequency is selected for ATmega32, with Prescaler F_CPU/8 for timer frequency.
Then F(timer) = FCPU/8 = 1 MHZ ---> T(timer) = 1us.
- Distance = 17000 x (TIMER value) x 1 x 10^-6 cm
= 0.017 x (TIMER value) cm
Note TIMER VALUE is the pulse width time calculated by the ICU
To deploy this project
Install the Following Software:
