Looking for practical Arduino projects? This guide shows how to control a relay from your smartphone using an Arduino Uno — either via Bluetooth or Wi-Fi.

HC-05 RX to Arduino Pin 11: This connects the receive (RX) pin of the HC-05 Bluetooth module to pin 11 on the Arduino. Pin 11 is configured as the TX pin in the software serial port (BTSerial), ...

Circuit Diagram Below is the circuit schema of the car control system, including the Arduino, L298N motor driver, and HC-SR04 ultrasonic sensor. Note: The pin numbers in the diagram may differ from ...

The App which I have made is connected to the master arduino through bluetooth. ... The Temperature and Humidity Sensor is connected to pin 9. The Main Gate Servo, Tank Servo and the Garage Servo are ...

Connect Rx (pin 2) directly to TXD of the HC-05. Since pin 3 cannot be connected to RXD (as the HC-05 expects 3.3V logic levels), a potential divider with 1k and 2k resistors is used to connect RXD to ...

The watch is built around an Arduino Pro Mini, a scavenged Nokia LCD, and a BlueSMiRF Gold. The Bluetooth connects to a Nokia N900 with a little Bluetooth client app [Ahmet] wrote.

The $22 kit includes an Arduino-BLE board and 6-pin header that should be fairly broadly applicable for building Arduino-based hardware that can communicate with iOS devices.

Primo will include Bluetooth LE (low energy), NFC, Wi-Fi, and infrared built-in — you typically need a “shield” add-on to get these features.