Plastic Remote Control 50 keys for LG 32LM563BPTC / LG 43LM5600PTC / LG 32LQ576BPSA TV
There are many types of infrared receiving heads, and pin definitions are different. Generally, there are three pins, including power supply pin, grounding pin and signal output pin. The receiver with corresponding demodulation frequency shall be selected according to different modulation carriers at the transmitting end.
The gain of the internal amplifier of the infrared receiving head is very large, and it is easy to cause interference. Therefore, a filter capacitor must be added to the power supply pin of the receiving head, generally above 22uF. Some manufacturers suggest that a 330 ohm resistor be connected between the power supply pin and the power supply to further reduce the power supply interference.
The infrared transmitter can be customized from the remote controller manufacturer, or it can be generated by the PWM of the single-chip microcomputer. It is recommended to use the infrared emitting tube (l5ir4-45) for home remote control to generate 37.91khz PWM. The PWM duty ratio is set to 1 / 3, and the emission waveform can be generated by a simple timing interrupt switch PWM