Sure-Trust-Final-Project

P. Harika G11-ES & IOT STM32 NRF24L01 Sensor Node with ESP32 NRF24L01 Gateway

1. Objective In this project, we aim to monitor sensor data wirelessly by integrating the NRF24L01 module with an STM32 microcontroller board and an ESP32 WiFi module. The system is divided into two main components:
2. Wireless Sensor Node: This consists of a sensing unit (BME280 Barometric Pressure Sensor), a processing unit (STM32F103C microcontroller), a transceiver unit (NRF24L01 wireless module), and a power supply (3.7V Lithium-Ion Battery).
3. WiFi Gateway: This component uses the ESP32 module and NRF24L01 to receive data from multiple sensor nodes and upload it to a cloud server (ThingSpeak) via a WiFi network. The gateway acts as a bridge between the sensor nodes and the cloud, performing critical functions such as protocol translation, data processing, and encryption. The project demonstrates efficient data transmission and real-time visualization using the IoT platform, ThingSpeak.
4. Components S.N. Component Name Quantity Description 1 ESP32 Board 1 Microcontroller with WiFi capability 2 STM32 Microcontroller 1 Bluepill board for sensor node 3 NRF24L01 PA+LNA 2 Wireless transceiver module 4 BME280 Barometric Pressure Sensor 1 Sensor for temperature, humidity, and pressure 5 Power Supply (5V) 2 Powering the components 6 Connecting Wires 20 For circuit connections 7 Breadboard 1 For prototyping 1 Final Project P. Harika G11-ES & IOT 2.1 Bluepill Board The Blue Pill is a compact, low-cost development board featuring the STM32F103C8T6 microcontroller (ARM Cortex-M3, 72 MHz, 64 KB Flash, 20 KB SRAM). It offers multiple GPIOs, UART, SPI, I²C, CAN, ADC, and PWM support. Breadboard-friendly, it includes a micro-USB port for programming and can be powered via USB or external sources. Compatible with Arduino IDE, PlatformIO, and STM32CubeIDE, it’s ideal for IoT, robotics, and prototyping, with extensive community support. 2.2 NRF24L01 Module The NRF24L01 is a 2.4GHz wireless transceiver designed for low-power, bidirectional communication. It supports a SPI interface (with 5V-tolerant pins) for compatibility with microcontrollers like STM32 and Arduino, and can communicate with up to six modules, enabling mesh networking. Key features include: • Operating frequency: 2.4GHz ISM band • Voltage requirement: 3.3V • Address range: 125 unique addresses • Transmission distance: Up to 100 meters 2 Final Project P. Harika G11-ES & IOT 2.3 ESP 32 The ESP32 is a powerful, low-cost microcontroller with built-in Wi-Fi and Bluetooth capabilities. It is ideal for wireless communication and IoT applications, offering dual-core processing (up to 240 MHz) and a range of peripherals. The ESP32 supports various interfaces like SPI, I²C, UART, and PWM, making it versatile for multiple projects. Key features include: • Connectivity: Wi-Fi (802.11 b/g/n) and Bluetooth (Classic and BLE) • Processing power: Dual-core, up to 240 MHz • Voltage requirement: 3.3V • Peripherals: GPIO, ADC, DAC, SPI, I²C, UART • Low power consumption: Ideal for battery-powered devices 2.4 BME280 Barometric Pressure Sensor The BME280 is a compact sensor that measures barometric pressure, temperature, and humidity. It communicates via I²C or SPI and operates at 3.3V to 5V. Key features include: • Pressure range: 300 to 1100 hPa • Temperature range: -40°C to +85°C • Humidity range: 0% to 100% RH Ideal for environmental monitoring and weather applications. 3 Final Project P. Harika G11-ES & IOT
5. Circuit Design 3.1 Sensor Node Using NRF24L01 & STM32F103C The sensor node is built using the STM32F103C microcontroller, NRF24L01 transceiver, and BME280 sensor. The BME280 measures temperature, humidity, pressure, and altitude. The NRF24L01 transmits this data wirelessly to the gateway. Connections: • NRF24L01: o VCC ➔ 3.3V (STM32) o CSN ➔ PA4 (STM32) o MOSI ➔ PA7 (STM32) o GND ➔ GND (STM32) o CE ➔ PB0 (STM32) o SCK ➔ PA5 (STM32) o MISO ➔ PA6 (STM32) • BME280: o Interfaced via I2C or SPI with STM32F103C 4 Final Project P. Harika G11-ES & IOT 3.2 WiFi Gateway Using NRF24L01 & ESP32 The gateway collects data from sensor nodes via the NRF24L01 and uploads it to the ThingSpeak server using the ESP32 WiFi module. This component bridges the sensor network and the cloud, ensuring seamless data transmission and visualization. Connections: • NRF24L01: o VCC ➔ 3.3V (ESP32) o CSN ➔ D5 (ESP32) o MOSI ➔ D23 (ESP32) o GND ➔ GND (ESP32) o CE ➔ D4 (ESP32) o SCK ➔ D18 (ESP32) o MISO ➔ D19 (ESP32) 5 Final Project P. Harika G11-ES & IOT
6. Program 4.1 Source Code/Program for Sensor Node #include <SPI.h> #include <Wire.h> #include <Adafruit_Sensor.h> #include <Adafruit_BME280.h> #include <nRF24L01.h> #include <RF24.h> RF24 radio(PB0, PA4); // CE, CSN on Blue Pill
   6 Final Project P. Harika G11-ES & IOT const uint64_t address = 0xF0F0F0F0E1LL; int counter = 0; float temperature; float humidity; float altitude; float pressure; #define SEALEVELPRESSURE_HPA (1013.25) Adafruit_BME280 bme; struct MyData
   { int counter; float temperature; float humidity; float altitude; float pressure; }; MyData data; void setup()
   { Serial.begin(115200); radio.begin();
   //Starting the Wireless communication radio.openWritingPipe(address); //Setting the address where we will send the data radio.setPALevel(RF24_PA_MIN); //You can set it as minimum or maximum depending on the distance between the transmitter and receiver. radio.stopListening();
   //This sets the module as transmitter if (!bme.begin(0x76))
   { Serial.println("Could not find a valid BME280 sensor, check wiring!"); while (1); } } void loop() { data.counter = counter; data.temperature = bme.readTemperature(); data.pressure = bme.readPressure() / 100.0F; data.altitude = bme.readAltitude(SEALEVELPRESSURE_HPA); data.humidity = bme.readHumidity(); Serial.print("Packet No. = "); Serial.println(data.counter); 7 Final Project P. Harika G11-ES & IOT

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Serial.print("Temperature = "); Serial.print(data.temperature); Serial.println("*C");

Serial.print("Pressure = "); Serial.print(data.pressure); Serial.println("hPa");

Serial.print("Approx. Altitude = "); Serial.print(data.altitude); Serial.println("m");

Serial.print("Humidity = "); Serial.print(data.humidity); Serial.println("%");

Serial.println();

radio.write(&data, sizeof(MyData));

Serial.println("Data Packet Sent"); Serial.println("");

counter++; delay(5000); }

4.2 Source Code/Program for ESP32 Wifi Gateway

#include <WiFi.h> #include <SPI.h> #include <nRF24L01.h> #include <RF24.h>

String apiKey = "C25ICK6FHOR7PST4";

const char* ssid = "Alexahome"; const char* password = "loranthus";

const char* server = "api.thingspeak.com";

RF24 radio(4, 5);
const uint64_t address = 0xF0F0F0F0E1LL;

struct MyData
{ int counter; float temperature; float humidity; P. Harika G11-ES & IOT

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float altitude; float pressure; }; MyData data;

WiFiClient client;

void setup()
{ Serial.begin(115200); radio.begin();

Serial.println("Receiver Started...."); Serial.print("Connecting to "); Serial.println(ssid); Serial.println(); WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED)
{ delay(500); Serial.print("."); } Serial.println(""); Serial.println("WiFi connected");

radio.openReadingPipe(0, address); //Setting the address at which we will receive the data radio.setPALevel(RF24_PA_MIN); //You can set this as minimum or maximum depending on the distance between the transmitter and receiver. radio.startListening(); //This sets the module as receiver }

int recvData() { if ( radio.available() )
{ radio.read(&data, sizeof(MyData)); return 1; } return 0; }

void loop() { if(recvData()) {

Serial.println("Data Received:"); Serial.print("Packet No. = "); P. Harika G11-ES & IOT

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Serial.println(data.counter);

Serial.print("Temperature = "); Serial.print(data.temperature); Serial.println("*C");

Serial.print("Pressure = "); Serial.print(data.pressure); Serial.println("hPa");

Serial.print("Approx. Altitude = "); Serial.print(data.altitude); Serial.println("m");

Serial.print("Humidity = "); Serial.print(data.humidity); Serial.println("%");

Serial.println();

if (client.connect(server, 80))
{ String postStr = apiKey; postStr += "&field1="; postStr += String(data.temperature); postStr += "&field2="; postStr += String(data.pressure); postStr += "&field3="; postStr += String(data.altitude); postStr += "&field4="; postStr += String(data.humidity); postStr += "\r\n\r\n\r\n\r\n";

    client.print("POST /update HTTP/1.1\n"); 
    client.print("Host: api.thingspeak.com\n"); 
    client.print("Connection: close\n"); 
    client.print("X-THINGSPEAKAPIKEY: " + apiKey + "\n"); 
    client.print("Content-Type: application/x-www-form-urlencoded\n"); 
    client.print("Content-Length: "); 
    client.print(postStr.length()); 
    client.print("\n\n"); 
    client.print(postStr); 
    delay(1000); 
    Serial.println("Data Sent to Server"); 
  } 
    client.stop(); 

} }

P. Harika G11-ES & IOT 5. Hardware Connections 11 Final Project P. Harika G11-ES & IOT 6. Output in Thingspeak 7. Applications Here are 5 applications for a STM32 NRF24L01 Sensor Node with ESP32 NRF24L01 Gateway project:

1. Wireless Environmental Monitoring: Use sensor nodes with various sensors (e.g., temperature, humidity, air quality) to collect data wirelessly and send it to a central ESP32 gateway for processing or cloud storage.
2. Home Automation: Sensor nodes can monitor environmental parameters (e.g., temperature, motion) and send data to an ESP32 gateway to trigger actions like controlling lights, fans, or HVAC systems.
3. Industrial IoT (IIoT): Deploy sensor nodes in factories or warehouses to monitor equipment health (e.g., temperature, vibration) and transmit the data to the ESP32 gateway for predictive maintenance and real-time alerts.
4. Smart Agriculture: Use sensor nodes in fields or greenhouses to monitor soil moisture, temperature, and humidity, sending data to the ESP32 gateway to optimize irrigation systems and environmental control. 12 Final Project P. Harika G11-ES & IOT
5. Wearable Health Monitoring: Integrate sensor nodes with health sensors (e.g., heart rate, temperature) worn by individuals, sending real-time data to an ESP32 gateway for healthcare monitoring or emergency alerts.
6. Conclusion This project successfully demonstrates how to use NRF24L01 and ESP32 for wireless sensor data monitoring. The integration of ThingSpeak enables real-time data visualization, making this system an efficient IoT solution for environmental monitoring and data analysis. 13 Final Project