In this illustration we will going to wire the HC-04,HC-05 or HC-06 module using serial communication with our Arduino board and 4 channel relay, we will going to control the relay on the Android smart phone or tablet via Bluetooth
How SPI, QSPI Serial to Peripheral Interface Woks ?
The SPI(Serial to Peripheral Interface) develop by Motorola and later adopted by Microwire of National Semiconductor and other companies. SPI is a hardware / firmware communication protocol or sometimes Engineers called it a “four wire serial bus” communication. The SPI
How to use I2C Bus Interface in Arduino with Sample Code
Using I2C (I square C) in Arduino interface , I2C is a standard for connection MCU and peripherals together. I2C is sometimes referred to as 2 wire interface or TWI. All the Arduino board have at least 1 I2c socket