Input Devices - PS70 Project

Project Overview

This week's project focused on developing an IoT-based environmental sensing device to measure temperature, pressure, and humidity using Bluetooth Low Energy (BLE). The philosophy behind this project was to create a low cost device that can be used for people to be mindful of their environment for sleep and optimize accordingly to maximize recovery.

Development Process

Environment Setup

Configured Zephyr OS for the nRF53 MCU, enabling Bluetooth, sensor functionalities, and PWM control for LEDs.

CONFIG_BT=y
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DEVICE_NAME="Thingy53"
CONFIG_SENSOR=y
CONFIG_PWM=y
CONFIG_BME680=y
CONFIG_IPC_SERVICE=y
CONFIG_LED_PWM=y
CONFIG_BOARD_ENABLE_CPUNET=y

Sensor Integration

Integrated the BME688 sensor for environmental data collection, implementing continuous reading of temperature, humidity, and pressure values.

sensor_sample_fetch(bme);
sensor_channel_get(bme, SENSOR_CHAN_AMBIENT_TEMP, &temperature);
sensor_channel_get(bme, SENSOR_CHAN_HUMIDITY, &humidity);
sensor_channel_get(bme, SENSOR_CHAN_PRESS, &pressure);

BLE Communication

Implemented Bluetooth Low Energy communication between the Thingy53 and a custom web interface for real-time data visualization.

Web Interface Features

BLE Connection

Direct connection to the Thingy53 via Bluetooth Low Energy.

Real-time Visualization

Dynamic display of environmental metrics with color-coded indicators for optimal ranges:

Temperature: 16-20°C (optimal range)
Humidity: 30-50% (optimal range)

Visual Feedback

RGB LED indicators on the Thingy53 showing environmental status:

Blue: Too cold
Green: Optimal conditions
Red: Too hot

Results & Testing

Thingy53 device with BME688 sensor integration

Real-time web interface displaying environmental data

Challenges & Solutions

Technical Challenges

Encountered temperature sensor calibration issues and power management concerns.

Solutions & Future Improvements:

Implement more accurate temperature sensor calibration
Optimize power consumption for longer battery life
Enhance data processing algorithms for more reliable readings

Project Impact

The IoT environmental sensing system successfully demonstrates the integration of multiple technologies:

Bluetooth Low Energy for wireless communication
Environmental sensors for data collection
Web interface for real-time monitoring
Visual feedback system using RGB LEDs

This project provides a foundation for future developments in environmental monitoring and smart home applications, particularly for sleep quality optimization.