I also DIY an Android Remote Control-all open source, diyandroid remote control

I also DIY an Android Remote Control-all open source, diyandroid remote control

I also DIY an Android Remote Control-all open source

 

1. Trial

 

I remember song Baohua put forward this theory in "device-driven development details": "Software and Hardware penetrate into each other's territory." This proof is true, you can use the upper-layer APP software and a simpler hardware design to complete a remote control.

I have developed an application. I am sending an E-mail to ask how the DIY infrared remote control on the Internet works. I checked two methods at present, one is based on USB and the other is based on the headphone jack. I simply replied to a message. Converts audio/USB signals to infrared signals. Afterwards, I felt a little perfunctory. Fortunately, I had some knowledge about the hardware and the software would also be developed. Combine them.

Trial combination, now the development rules are clear, usually first try to learn about the approximate function. The secondary combination of the trial is to buy a plug-in remote control transmitter on the Internet as shown in the following internal figure (ignore the line, the line is my measurement and welding ).

For software use on mobile phones, refer to "Remote Control Genie" (version 2.9.3). skyworth TV is the test electric appliance. The software design is relatively easy to use and trial is successful without any other obstacles.

 

2. DIY hardware

 

The second step is DIY, and Google's [DIY] is cheap and easy to use-use the IR controller of the ear machine hole (the caster can be used for broadcasting. WAV player) Long-distance and mobile phone remote control, 5mm headphone interface infrared remote control transformation analysis two articles and one principle article Remote Control Principle. combined with the use of the oscilloscope test button is the output waveform of the headphone jack, probably understand its principle and the components required by DIY.

 

DIY components: 1. 3.5 earphone plug 2. infrared Emission tube (in fact, this name is also strange, in a strict sense it belongs to the Light Emitting Diode and a type, but go to the electronic mall to buy it before "infrared emission tube 」)

 

The following hardware-related experiments are partially replaced. The software uses the compatible configuration on the remote control Genie and connects the connected remote control to perform the test. For the first time, based on the first reference, the left and right channels connecting two diodes to the headset plug are as follows:

Lab results: no error occurred.

The second experiment was based on the second reference article to weld only one launch tube. The experiment result is: The success is correct.

In the third experiment, the positive and negative sides are reversed and the test result is the same: the success is correct.

 

From the three experiments above, many concepts have been clarified, but it also brings a lot of doubt. In the first article, we will say that we want to convert the 19kHz to the 38kHz, so we need to connect the two transmitting tubes plus and minus each other, however, in the second experiment, signals can be sent without intercommunication. In the third experiment, reverse swapping does not affect normal signal transmission and reception. This is also a point. The third point is that there is no transistor to zoom in. It can also be used. Put the theoretical discussion here for the time being. Continue the new experiment.

 

The software experiment is to develop an APP to launch data.

The first step is to record the audio output by the remote control genie. The hardware connection uses a public earphone plug to record the key waveform output by the remote control genie. Put it in your phone to play the audio to send an infrared signal to the TV. Verification passed.

 

2. DIY software

 

After the overall principle is smooth, the dashboard plan is started, and an open-source version of the remote control genie is compiled, that is, the code is used to implement the live waveform. The parameters of the signal can be adjusted to control different types of devices.

 

According to the remote control principle, we know that a sine wave signal of kHz is required. First, we can find out how to generate a sine wave in Playing an arbitrary tone with Android. The test found that the output was not 38 kHz, and the maximum was only 20 KHz. In turn, the output frequency of the remote control genie was also 20 KHz, so the 20 kHz signal was used for the time being. Make a slight change so that it outputs a single channel sine signal of 20 kHz.

 

Also according to the length of the waveform specified in the remote control principle, encoding is performed, but section (3) is ignored. The following methods are implemented: getleaderCode, getUserCodeToWave, getDataCodeToWave, and getStopBit obtain the waveforms of each phase respectively. Version 0.1 is released after it is combined. The source code is located at: https://code.csdn.net/kangear/sinewave. Currently, you can control a skyworth TV. :

 

 

 

 

There are still many defects to be improved:

1. The current failure rate is still relatively high, four successes once.

2. Currently, only one key is implemented. You can modify usercode and datacode through code.

3. Based on the single-channel waveform, you can only connect one location on the left and right channels on the hardware. The reference software allows any combination of hardware connections before the left-right corner.

 

 

Android Open Source

Android is one of the most popular mobile terminal operating systems
But open source is the only one
It has great advantages over IOS Saipan WP.
However, the disadvantage is software development and profitability.

The starting point of Google's launch of this operating system is to make money for the traffic. The underlying source code is open-source, and major manufacturers are willing to cooperate.
Samsung LG sharp Motorola international brand in addition to iPhone and novogene are using Android systems, of course, the domestic is even more boring in TCL Xia xinjiayu Tianyu Changhong Haier Xiaomi, etc.
Because of the open source, there are DIY systems, private self-made systems, cloud systems, and so on.
Each vendor is designed based on its own
Xiaomi's MIUI is a very successful example of making money. No more gorgeous systems can be achieved only when the android native system is used as the underlying layer.
Therefore, Android frameworks and services account for a large proportion.
These vendors can do whatever they want after paying a small amount of money to get Google's authorization.
But how did the vendor make money?
Custom software information fee or traffic fee
Please do not repeat the details.

Android mobile phone systems are open-source.

If you do, you can easily DIY... the simple definition of open source is: Ah ~ It's really hard to say...
Let me give you an example.
For example, if your phone card is not open-source, you can only use it to make phone calls. But maybe, when will your phone bill be deducted for no reason... you don't know what's going on, but if your mobile phone card is open-source, if you can read the source code, you will know if someone else has written the code to steal your mobile phone, if you modify the source code, you can DIY it, program it into a bus card, or anything else ....
In short, open source not only allows you to know how to use it, but also helps you know why it can be used in this way.