STM32 Project: LDC1614 Sensor Data Acquisition and UART Transmission

Overview

This project demonstrates how to interface an STM32 microcontroller with the LDC1614 inductance-to-digital converter using the I2C protocol. The acquired data is processed and transmitted over UART, and an onboard LED is controlled based on sensor readings.

Features

• I2C Communication: Reads data from the LDC1614 sensor.
• UART Transmission: Transmits sensor data to a terminal via UART.
• GPIO Control: Turns on an LED based on sensor data thresholds.
• Data Processing: Combines multiple sensor readings into 16-bit values and converts them to readable formats.

Hardware Requirements

• STM32 Microcontroller (e.g., STM32F4xx)
• LDC1614 Sensor
• UART Interface (for serial communication with a PC or terminal)
• LED (connected to GPIO pin for status indication)

Software Requirements

• STM32CubeIDE (or any IDE that supports STM32 development)
• STM32 HAL Drivers for I2C, UART, and GPIO

How It Works

1. I2C Communication: The STM32 communicates with the LDC1614 sensor over the I2C bus. Sensor data is read from registers such as DATA_MSB and DATA_LSB for both channels (Channel 0 and Channel 1).

2. Data Processing:

   • The MSB and LSB bytes are combined into 16-bit values.
   • These 16-bit values are converted to hexadecimal and decimal formats for easier interpretation.

3. UART Transmission:

   • The processed sensor data is formatted into a string and transmitted over UART. This allows real-time monitoring of sensor readings on a connected terminal.

4. LED Control:

   • If the processed sensor data exceeds a predefined threshold (310 in this example), the onboard LED is turned on. Otherwise, it remains off.

Code Structure

main.c

• Initialization:

  • The HAL library is initialized, and the I2C, UART, and GPIO peripherals are configured.

• Main Loop:

  • The code runs in an infinite loop where it:
    • Reads data from the LDC1614 sensor using the LDC1614_ReadRegister function.
    • Processes the sensor data by combining MSB and LSB bytes and converting them into readable formats.
    • Transmits the sensor data via UART using the Transmit_Data function.
    • Toggles the onboard LED based on sensor readings.

Key Functions

• LDC1614_ReadRegister(uint8_t reg, uint8_t* buffer, uint16_t size):

  • Reads data from the specified LDC1614 register using I2C.

• Transmit_Data(uint16_t MSB_CH0, uint16_t LSB_CH0, uint16_t integerValue_MSB_CH0, uint16_t MSB_CH1, uint16_t LSB_CH1, uint16_t integerValue_MSB_CH1):

  • Formats the sensor data into a string and transmits it over UART.

• hex_to_dec(uint16_t hex):

  • Converts a hexadecimal value to a decimal integer.

Example UART Output

LED Behavior

• The onboard LED will turn on if the sensor data for either channel exceeds a threshold value (e.g., 310), indicating a significant change in inductance.

Setup and Usage

Hardware Connections

1. LDC1614 Sensor:

   • Connect the sensor to the STM32 I2C pins (SCL and SDA).
   • Ensure the sensor's I2C address matches the one defined in the code.

2. UART:

   • Connect the UART TX pin to a PC or terminal for monitoring sensor data.

3. LED:

   • Connect an LED to the corresponding GPIO pin (e.g., LD2_Pin on STM32F4xx).

Build and Flash

1. Open the project in STM32CubeIDE.
2. Build the project to generate the binary.
3. Flash the binary onto the STM32 microcontroller.

Monitor Sensor Data

• Use a terminal program (e.g., PuTTY, Tera Term) to monitor the data transmitted via UART.
• The data will be in the format shown in the "Example UART Output" section.

Customization

• Threshold Adjustment: Modify the threshold value for the LED in the main loop to suit your application needs.

  if (integerValue_MSB_CH0 > 310 || integerValue_MSB_CH1 > 310) {
      HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_SET);
  } else {
      HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
  }

This README.md file provides an overview of the project, including features, setup instructions, and customization tips. It should help users understand how to implement and work with your STM32-based LDC1614 sensor project.