HCSR04 Ultrasonic sensor and STM32

In this project, we will be interfacing an HC-SR04 Ultrasonic sensor with the STM32 microcontroller. To visualise the output, UART communication is utilized to send the data over a cable to a connected PC or laptop. The result can then be observed through the console of the STM32 IDE.

HC-SR04 Interfacing

Create a new project by selecting "New" and then choosing "STM32 Project."

Please select the targeted board correctly (B-L072Z-LRWAN1) and click on Next.

Provide the project name and click on Finish.

Now we have a configuration page that looks like this.

Click on Pinout ->  Clear Pinouts

Now, on the left side, click on Connectivity.

Select USART2 and set the mode to Asynchronous.

PA2 should be configured as USART2_TX.

PA15 should be configured as USART2_RX.

Expand Timers and Enable TIM2

Select "Clock Source" and choose "Internal Clock"

Expand "System Core" and Enable RCC

Select High Speed Clock (HSE) and choose Crystal/Ceramic Resonator.

Set PB9 - GPIO_Output

Set PB8 - GPIO_Input

save it. It will generate the code.

Make changes in the main.c file based on the below code.

HC-SR04 Code id available here 

Right click on the Project -> Project Properties -> C/C++ build -> Settings -> MCU GCC Linker -> Miscellaneous -> click on add button in the Other flags -> add this "-u _printf_float"

Build the project

Debug the project 

Open the command shell console to view the output.

Click on the resume button.

The distance is shown in the console window.