STMicroelectronics STEVAL-MKI029V1

Overview

STEVAL-MKI029V1 from STMicroelectronics is a handheld inclination analysis demonstration board built around the STM8S207R6 8-bit MCU and LIS331DLH 3-axis MEMS accelerometer. It detects tilt on X/Y axes, free-fall, and circular motion, visualizing results via dual concentric rings of multicolor LEDs and a central bi-color LED, with audio feedback via integrated buzzer - designed for educational demos, sensor evaluation, and motion-aware interface prototyping.

For engineers reviewing the STEVAL-MKI029V1 datasheet, STEVAL-MKI029V1 pinout, STEVAL-MKI029V1 application, or STEVAL-MKI029V1 equivalent, this board serves as a ready-to-run platform for rapid validation of MEMS-based motion sensing, low-power wake-on-motion behavior, multi-mode UI feedback (LED/music), battery monitoring, and SWIM-based in-circuit debugging of STM8 firmware.

Technical Context

The board implements a real-time motion classification system using the LIS331DLH's digital I²C interface (SCL/SDA), interrupt-driven event detection (INT1/INT2), and configurable thresholds for tilt, free-fall, and motion. The STM8S207R6 processes sensor data, manages six user-selectable operating modes (3 musical + 3 silent), drives 20 discrete LEDs across inner/outer rings, and controls an audible buzzer on PA3.

Power management includes automatic standby entry after 10 s of inactivity, wake-up triggered by MEMS interrupts, and battery voltage monitoring (via PF3 and PD6) with low-battery alert and safe shutdown. Power is supplied by three AAA cells (4.5 V nominal), regulated by the L6926 DC-DC converter to 3.3 V for logic and sensors.

Key Specifications

Availability

STEVAL-MKI029V1 is available at Aetrix Electronics and suitable for sensor education labs, MEMS evaluation programs, embedded motion UI prototyping, and industrial training seminars requiring stable component supply and out-of-box functionality.

Supply support for STEVAL-MKI029V1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, sensors, power ICs, and analog components for industrial, automotive, and consumer applications.

This board belongs to ST's STEVAL (ST Evaluation) series - purpose-built demonstration platforms that integrate ST silicon with reference firmware and intuitive UI to accelerate learning, validation, and early-stage design of motion-sensing, low-power, and human-interface systems.

FAQ

Does STEVAL-MKI029V1 support UART or USB communication?

No. The board lacks UART transceivers or USB interface hardware. Communication is limited to SWIM debugging via the 4-pin connector and onboard pushbuttons/LEDs for user interaction. Sensor data is not exposed externally beyond visual/audio output.

Can the firmware be modified or reprogrammed?

Yes. The STM8S207R6 is fully reprogrammable via the SWIM interface using ST Visual Developer or Cosmic compiler tools. Source code and firmware examples are available from ST's official documentation archive under Doc ID 15631.

What is the role of the L6926 voltage regulator on this board?

The L6926 is a synchronous step-down DC-DC converter that efficiently regulates the 4.5 V battery input to a stable 3.3 V supply for the MCU, MEMS sensor, and LEDs - enabling extended runtime and consistent performance across battery discharge.

Is the LIS331DLH accelerometer accessible for custom integration?

Yes. The LIS331DLH is connected via standard I²C (PC5/SCL, PC7/SDA) and chip-select (PE5/CS), with interrupt outputs routed to PE3 and PE4. All signals are exposed on the MCU's GPIO pins, allowing direct firmware access and reconfiguration without hardware modification.