Wireless Relay Control using IC2262/2272 and ATmega328PB
Created: Nov 20, 2016
No description available.
The AVR ATmega328PB device is an 8-bit microcontroller with 32KB program memory size. This new PB version features an additional USART and SPI communication interface. It has also increased the number of available timers or counters. A new Port E has been added in this version, which results in an increase of GPIO pins from a number of 23 to 27. These additional features enable the ATmega328PB microcontroller to support more tasks. The IC2262/2272 is a 4-channel wireless remote control kit, which can be interfaced directly to the ATmega328PB microcontroller. It has a transmitter with four controls and a receiver that has four outputs that can be connected to the ATmega328PB GPIO pins.
In this reference design, the ATmega328PB microcontroller controls four relays with the command sent wirelessly by the IC2262/2272 transmitter. The IC2262/2272 module operates at 315MHz with the use of amplitude shift keying modulation technique. The output pins (D0-D3) of the receiver provide a non-latching output whenever the pushbuttons (A-D) at the transmitter are pressed. These output pins (D0-D3) are connected to the PORTD pins (PD0-PD3) of ATmega328PB, which are configured as input pins. The other pins on PORTD (PD4-PD7) are configured as output pins. These pins (PD4-PD7) provide a latching output to the optocouplers to saturate the transistors, which energizes the coil of the relays. Initially all relays are OFF. If pins PD0, PD1, PD2, and PD3 detect a HIGH signal, pins PD4, PD5, PD6, and PD7 outputs a HIGH signal, respectively. These will make the relays turn ON. If the input pins (PD0-PD3) will detect a HIGH signal again, pins (PD4-PD7) will give a LOW output and the relays will turn OFF. The advantage of these non-latching outputs of the receiver is that, each of the relays can be turned ON or OFF with the use of a single push-button and a single input pin from the microcontroller.
The IC2262/2272 transmitter is powered by a 12V battery. The receiver and the microcontroller operate with a 5V power supply. The optocouplers, transistors, and relays use a separate 12V power supply to isolate the high voltage devices attached to the relay contacts from the low voltage devices use in this circuit just like the microcontroller and receiver. These 4-channel relays can be used to switch ON or OFF lights or small home appliances. With the help of ATmega328PB microcontroller and IC2262/2272 module, lights and small appliances can be turned ON or OFF conveniently. The transmission distance of the IC2262/2272 module reaches from 50 meters up to 100 meters.