Mobile phone remote control, 3.5mm headphone Interface Infrared Remote control transformation analysis

Many home appliances are used infrared remote control, such as TV, set-top box, air conditioning, electric fans. More and more remote control has brought us more problems, sometimes can not find where the remote control, or confusion is the trouble, in fact, the simple transformation of the mobile phone, it is possible to homemade a universal infrared remote control, to see how we "control" home appliances.

Solution: The infrared remote control when sending data, is the binary data is modulated into a series of pulse signal with a 940nm wavelength of the infrared emission tube emitted, the infrared carrier is the frequency of 38KHz square wave, the infrared receiver at the receipt of 38KHZ carrier signal will be output low level, otherwise the output high level, so that can be " When the continuous "infrared light signal is demodulated to a certain period of successive square wave signal, and then through the integration of infrared receiver Head Demodulation can recover the original data signal. The receiving part is with the integrated infrared receiving head, it will be infrared receive diode, amplification, bandpass filter, demodulation, shaping and other circuits to do together, when received this code, the microcontroller will encode the analysis and processing, so as to achieve the control of household appliances.

The second method adopted by the ordinary MP3 audio 0, 1 encoding, and then amplified by the transistor and loaded into a 555-based circuit issued by the 38K carrier, by amplitude modulation to achieve remote control.

Material: 940nm infrared emitting tube, 3.5mm headphone male, NE555 integrated block, 10K resistor, 4.3K resistor, 1.8nf capacitor, 10nf capacitor, 80,503 pole tube, 3.7V lithium battery, Hole board (Universal circuit board), used earphone cable.

Tools: soldering iron, scissors, hot melt adhesive, tape, etc.

Software: Adobeaudition CS6 (Windows platform), Remote Control Wizard (iOS platform).

Smart Phone Infrared Transformation Program: Software + infrared emission diode

On the smartphone to transform the infrared remote function is actually very simple, we through the 3.5mm headphone jack, make a pluggable infrared emitter, and then through the software to complete the infrared remote control.

First of all, to prepare a 3.5mm headphone plug, preferably with a metal tail cover, so that the welding of the infrared tube installed in the inside, only exposing the LED part, not only beautiful can also play to protect the role of infrared emission LEDs. Unscrew the metal tailgate portion of the 3.5mm headphone plug, and you can see the exposed three weld points, from the rear to the left, right and ground.

The production of infrared remote control only in the left and right channel welding, the first infrared led two pins respectively cut into 1cm and 1.2cm (because the left and right channels in the audio signal is an AC signal, so the infrared light-emitting diode will be in the positive half of the AC or negative half cycle is conducted to work, not the polarity), Then use a soldering iron to weld the two poles of the IR LEDs to the left and right channels of the headphone plug.

The infrared LED Poles are welded to the left and right channels of the 3.5mm plug

Because the headphone plug is copper, thermal conductivity is very strong, so do not use the hands of the welding with the headset plug welding, in case of Burns, with a wooden clip clamp and then weld on the line. Copper plug thermal conductivity is also caused by the local solder point temperature is low, in the welding time we can put the soldering iron on the solder joint more contact 2, 3 seconds, so that the solder completely melted, to avoid the occurrence of false welding. Finally, the metal tailgate with the 3.5mm headphone plug is finished.

On the Apple or Android phone download "Remote Control Wizard" Software, enter the advanced settings, Zaza Maximum volume to 100% (increase the volume to improve the transmitting power), and then return to the "remote"-"add" select the corresponding brand of equipment, if not know what device can also be in the matching interface according to the prompt remote control matching.

The use of "Remote Control Wizard" interface is more intuitive and easy to get started

Simple infrared emitter production completed

Non-intelligent machine and MP3 Retrofit scheme: Audio file +38k infrared emission

Is there a way for non-smartphones or mp3/4 to get them to implement infrared remote control? The answer is yes. First use 555 to make a 38KHZ circuit, and then use the audio signal loaded in the transistor of the base pole as a switch to control the occurrence and stop of 38KHZ, so that the infrared led issued with a binary code 38KHZ carrier on the line.

STEP 1 To make 38KHZ occurrence circuit

According to the circuit diagram in the hole plate welding NE555, due to the few components, so the author directly with solder wire soldering circuit, note that some need to jumper the best place to use enameled wire welding, to prevent solder wire jumper short circuit. Finally, the welding audio line is connected to the transistor base on the right channel, and the ground connection transistor emitter (left channel is not connected).

38KHZ Occurrence circuit diagram

38KHZ occurrence Circuit of welding completion

STEP 2 Recording Infrared audio

Open the Adobe Audition CS6 software, create a new audio file with a sample rate of 96000, then insert a scrap of headphone cable on the 3.5mm jack of the microphone, point to the "record" red button, then make some noise by talking casually, If there is a level fluctuation at the bottom of the screen, the microphone next to the laptop camera also works. In order to minimize interference when recording infrared audio, the cable that connects the laptop's built-in camera must be unplugged.

Unplug the laptop's built-in camera cable to prevent interference

Click "Record" again, the track is smooth, no fluctuations, indicating that the built-in microphone fails, and now completely rely on the 3.5mm Jack recording, the next can be recorded on the remote Control infrared audio.

Using a soldering iron to remove the remote control infrared emitter, the circuit board originally to the infrared LED power supply of the two poles are welded in the old headphone line of the left channel and ground.

The ground and the left channel are welded to the remote control circuit board, if not recording can try to change the line and the left channel line sequence

Click "Record", press the remote control of any key, at this time the computer screen will appear a small ripple, this is the infrared waveform, stop recording, with the mouse wheel to enlarge the infrared waveform just recorded, we can clearly see the remote control of the Guide Code and address code and so on.

Infrared audio captured by the microphone

Zoom in to see the Guide code and data code clearly.

Amplitude gain 48DBI for improved audio output voltage

Can be in a recording of the remote control all the keys in turn, recorded their respective keys of the infrared audio, respectively, each key to create a new audio file to save, because the high-frequency 38KHZ is not issued by it, so the sampling rate and the number of bits is not too large, generally 8-bit. Next, you just need to connect the previously produced 38KHZ circuit to the MP3 of the downloaded infrared audio file, click to play the music will be equivalent to press the button corresponding to the remote control.

Save infrared audio file as WAV or MP3 format

Trial Summary: Smarter with the Siri experience

By playing audio files for infrared remote control is basically suitable for all MP3, MP4 and other digital products, before use, remember to adjust the headset volume to the maximum, In this way from the 3.5mm headphone hole out of the voltage is enough to guide the transistor base to generate a 38KHZ carrier, the general infrared emission led to the remote control of the infrared receiver head remote control, can reach 6, 7 meters far remote distance.

Of course, you can also connect it to Apple Siri to make a voice-activated infrared remote. Name the audio file a specific name, such as "Blue", and then use the Apple Assistant to import the audio into the iphone and say, "Play blue" in a few seconds, the blue light will light up. But you have to add "play" two words to the file name, or Siri will prompt you to find no blue in your contacts. Each time can only say "Play open air Conditioning", "play off the TV" and other awkward statements, but this voice-activated power is quite interesting.

Talking to Siri, playing blue breathing.

A single-chip microcomputer-controlled small lantern will turn into a blue slow breathing light

Mobile phone remote control, 3.5mm headphone Interface Infrared Remote control transformation analysis