MPU 6050 Interfacing Renesas RA

In this Instructable, you’ll learn how to build a compact, high‑performance motion data logger using the Renesas RA6M4 microcontroller and the MPU6050 6‑axis IMU sensor. Leveraging the Renesas Flexible Software Package (FSP), this project demonstrates how effortlessly you can configure I²C and UART drivers through simple, well‑structured APIs, and shows how quick it is to get up and running with minimal boilerplate.

The RA6M4 stands out with its:

1. Rich Peripheral Libraries: The FSP provides preconfigured middleware stacks for I²C, UART, and timing, letting you call R_SCI_I2C_Open, R_SCI_UART_Open, and SysTick_Config without manual register tinkering .
2. Easy Sensor Configuration: A dedicated MPU6050_Config(&myConfig) function encapsulates all accelerometer, gyroscope, clock source, and DLPF settings in just one call .
3. Seamless Data Streaming: By calling MPU6050_Get_Accel_Scale and MPU6050_Get_Gyro_Scale inside a simple 1 Hz loop, sensor readings are formatted via snprintf and transmitted over UART with R_SCI_UART_Write—providing human‑readable output for PC logging or wireless modules .
4. Portability Across RA Series: All Renesas RA MCUs share the same FSP structure. You can migrate this code to any other RA family member by adjusting only the HAL configuration—no low‑level code changes required.

Whether you’re a hobbyist building a DIY motion tracker or an engineer prototyping a robotics or wearable‑tech application, this project illustrates how the RA6M4’s powerful hardware and Renesas’s intuitive software ecosystem make IMU interfacing both robust and remarkably straightforward. Let’s dive in!

Below is a list of the hardware and software items you’ll need to get started.

Hardware

1. Renesas MCU Board (EVK) e.g. EK-RA2E1, EK-RA6M4, or any FSP‑supported evaluation kit
2. Power Supply / USB Cable
3. TTL Module
4. MPU6050 Sensor Module
5. Software: E2 studio with Any FSP Pack
6. Serial Port utility
7. Optional: Logic Analyzer

Begin by wiring the MPU6050 sensor and the UART TTL interface to your RA6M4 development board as follows:

1. Power & Ground
2. Connect VCC of the MPU6050 to the 3.3 V rail on your RA6M4 board.
3. Tie GND of the MPU6050 and the TTL adapter to the RA6M4 board’s GND pin.
4. I²C Lines (MPU6050)
5. SDA → RA6M4 P101
6. SCL → RA6M4 P100
7. UART TTL Interface
8. TX (transmit from RA6M4) → TTL adapter RX pin on header P113
9. RX (receive into RA6M4) ← TTL adapter TX pin on header P302
10. Common Ground
11. Ensure the TTL adapter’s ground is also tied to the RA6M4 ground to establish a common reference.

Once all connections are secure, power up the board. You’re now ready to configure the FSP I²C and UART instances in software to begin communicating with the MPU6050 and streaming data over the serial link.

1. Download the Project Archive
2. Open the link:
3. https://drive.google.com/file/d/1Az2xnxq28miGLmXS_qujA0-gkQyPCso8/view?usp=sharing
4. Click Download (the ↓ icon) to save the ZIP file (e.g. RA6M4_MPU6050_UART_Project.zip) to your PC.
5. Extract the ZIP
6. Navigate to your Downloads folder (or wherever you saved it) and right‑click the ZIP.
7. Choose Extract All… (Windows) or Unzip (macOS/Linux) to unpack the folder—e.g. RA6M4_MPU6050_UART_Project.
8. Launch e² studio
9. Start e² studio.
10. Import the Project
11. In e² studio’s menu bar, choose File → Import…
12. In the Import wizard, expand General and select Existing Projects into Workspace, then Next.
13. Click Browse… next to Select directory, and navigate to the extracted folder RA6M4_MPU6050_UART_Project.
14. The project should appear in the “Projects” list. Ensure it’s checked, then click Finish.
15. Verify FSP Configuration
16. In the Project Explorer, expand your newly imported project.
17. Open configuration.xml to launch the FSP GUI.
18. Confirm that the I²C instance is assigned to pins P101/P100 and the UART instance to P302/P113. in stacks tab
19. Click generate project content buttion in upper right.
20. Build the Project
21. Right‑click the project in Project Explorer → Build Project.
22. Confirm the build completes without errors—object files and the final .elf will appear under the Debug folder.

You’re now ready to flash the firmware to your RA6M4 board and begin real‑time MPU6050 data streaming over UART!

All of the MPU6050 interfacing magic happens behind the scenes in mpu6050.c, with all of its command signatures and data structures declared neatly in mpu6050.h. Meanwhile, main.c (sometimes called hal_entry.c in FSP parlance) takes care of the heartbeat of the system: the millisecond SysTick counter, simple delay functions, and the endless loop that drives UART output.

In mpu6050.h, you’ll find everything needed to talk to the sensor:

• i2c_write_byte(), i2c_read(), i2c_read_byte() for blasting commands and fetching raw registers

• MPU6050_Config() for resetting and programming power, clock, filter, and full‑scale settings

• MPU6050_Get_Accel_RawData(), MPU6050_Get_Accel_Scale(), MPU6050_Get_Accel_Cali() for raw, scaled, and calibrated acceleration

• MPU6050_Get_Gyro_RawData(), MPU6050_Get_Gyro_Scale() for angular‑rate measurements

…plus the MPU_ConfigTypeDef struct that ties all your chosen settings together.

Open mpu6050.c and you’ll see those prototypes come to life: the little I²C wrappers that pack and unpack bytes, the interrupt callback (sci_i2c_master_callback) that flips a flag when a transfer finishes, the MPU6050_Config() routine that writes dozens of registers in the right order, and every helper that turns raw register data into human‑friendly g and °/s values.

Jump over to main.c, and you’re in the world of real‑time control:

1. SysTick_Handler fires every millisecond to keep a global tick count
2. delay_ms and get_ticks give you both blocking and non‑blocking timing
3. hal_entry (your effective main()) opens the I²C and UART channels, calls MPU6050_Config twice (once for reset, once for setup), then settles into a once‑per‑second routine: read accel and gyro, run snprintf to build a text packet, then hand it off to R_SCI_UART_Write for streaming to your PC or logger.

Under the hood, each function does exactly one thing—whether that’s toggling a pin, reading six bytes, or formatting a string—making it a breeze to trace, debug, or lift wholesale into any other RA-series project.

With your project built, connect your RA6M4 board to the PC via the debug interface. In e² studio, right‑click the project and choose Debug As → Renesas GDB Hardware debuging The IDE will download the firmware and halt at the very start of system initialization. Click the green Resume button (▶) and you’ll briefly step through the auto‑generated R_SystemInit() before landing in your own hal_entry()—that’s when your MPU6050 configuration kicks in.

Next, fire up your favorite serial‑port terminal (PuTTY, Tera Term, or the built‑in e² studio Serial Console). Select the COM port assigned to your ttl UART adapter, set it to the same baud rate of 115200 you chose in FSP (e.g. 115200 stack), and hit Open. You should immediately see a stream of acceleration and gyro readings scrolling by once per second. If you click Reset in e² studio or power‑cycle the board, you’ll observe the MPU briefly recalibrating itself—every reset triggers your MPU6050_Config() routine again—before the fresh data flow begins anew.

You’ve now built a complete RA6M4‑based motion logger—from wiring the MPU6050 and setting up I²C/UART in e² studio, through diving into modular driver code, all the way to flashing the board and watching live acceleration and gyro data scroll by in your serial terminal. Thanks to Renesas’s FSP abstraction, the same code can be retargeted to any other RA‑series MCU simply by reassigning pins and peripherals in the FSP configurator, with zero changes to your sensor logic. If you run into any questions—whether it’s about porting this project to a different RA controller, tweaking filter and scale settings, or anything else related to the code or hardware setup—please drop a comment below. Happy logging!