Overview

Me IR Remote Controller is a portable device applicable to wireless remote control robot, electric cart, and other mechanical device. It has a keyboard with 3×7 keys (letter A-F, number 0-9, arrow keys and center key) and its power supply is a button cell. Featuring sensitive keystroke and friendly feedback, it is often used with Me IR Receiver for easy construction of wireless controlling model.

Technical specifications

● Operating voltage: 2.25 V~3.9 V
● Operating current: 6 mA~25 mA
● Quiescent current: ≤ 3 μA
● Infrared wavelength: 940 ± 50 nm
● Carrier frequency: 37.9 ± 0.2 KHz
● Power supply: 3V button cell, type 2025
● Operating temperature: -40~85℃
● Housing material: environmental-friendly
● Keystroke life: ≥ 80,000
● Environment luminance:natural light or fluorescent lamp 200 ± 50LX
● Module size: 90 x 41 x 12 mm (L x W x H)

Functional characteristics

● Easy coding and decoding, and multi-channel remote control
● Target to Me IR Receiver when used in close range
● Adopt NEC IR protocol

Code value of key (in hex)         

Principle analysis

Adopting near infrared (wavelength 0.76~1.5 μm) to transmit the control signal, the IR remote controller is composed of a microprocessor chip, a crystal oscillator, an amplifying transistor, an infrared emitting diode and a keyboard matrix, which produce the remote signal.

Working principle: The internal oscillator in microprocessor chip and external oscillating crystal X constitutes a high frequency oscillator to generate a high-frequency oscillation signal of 480 kHz. This signal is fed into a timing signal generator to generate a sinusoidal signal of 40 kHz and a timing pulse signal. The sinusoidal signal is fed into the encoding modulator as a carrier signal, the timing pulse signal is fed into the sweeping signal generator, and the keying input encoder and the instruction encoder are used as the time standard signal of these circuits. The scanning pulse signal is fed into the keyboard matrix circuit, when a key is pressed, the control signal corresponding to the function keystroke is fed into the keying encoder, and a digital signal with corresponding function is output.

Then the finger encoder outputs an instruction code signal which is modulated onto the carrier signal by the modulator to form into a high-frequency pulse string containing the function information. The pulse string is amplified by a transistor, and drives the Infrared Emitting Diode (IRED) emitting a pulse modulated signal. In the receiving process, the infrared signal is fed into the optical filter and photoelectric diode, and then converted into an electric signal of 38 kHz. This signal is processed by amplification, demodulation, reshaping, and demodulation, and then fed into the decoding and port circuit; thereby the corresponding remote control function is completed.