[Training Camp] Internet of Things Infrared Wireless Remote Control-483530A

2020,11,2 6

Function description

    This project is developed based on the Tuya Smart IoT module and requires no code development.

    Connected to the Tuya platform

    Low cost, lightweight

    USB powered

    Remote operation is possible as long as there is a network

    Supports any infrared remote control home appliances and has infrared learning function.

Reason for production: 

    Why do I want to think about this thing? Mainly because winter is here and it will be very cold at night if the air conditioner in the dormitory is not turned on in advance, so some colleagues bought a WiFi remote control. After I saw it, the effect was very good (it is also connected to the Tuya platform. And it can be operated by Siri voice, which is very enviable), and Lichuang just happens to have a training class. So I might as well make one myself. The point is that the module can be used for free~~~

   In fact, at first I wanted to follow the tutorial and make an RGB lamp or something. At first, I was afraid that my programming skills were not good enough. Later, I found that this module did not require programming at all. I only needed to draw the PCB, so on the Tuya platform After looking around, I happened to find this WiFi air conditioner socket project, so I simply omitted the socket part and made a WiFi remote control. The most important thing is to be able to have sex for free~~~

Production ideas:

     Next, let’s talk about the production process. First of all, of course, I looked for a suitable solution on Tuya's official website. After comparison and selection, I found a WR3E module that is more suitable. It can be used to measure electricity and can also add relays to control high-power electrical appliances. Of course, the board I designed is limited in size. , only the infrared remote control and infrared learning functions are added, and the rest of the functions are reserved on the board. You can use an external base plate to use other functions. The red emitting tube uses a 3mm white wavelength of 940nm, and the infrared receiving tube is going to use HS0038. The effect will be tested after assembly is completed. (The 1838 used later, the one with the iron case, Taobao offers free shipping for 20 cents each)

     After choosing the appropriate solution, it is time to draw the schematic diagram. This is a less detailed schematic diagram on Tuya's official website. I drew it based on the schematic diagram on the official website plus the information in the configuration firmware. Of course , the configuration on the official website The firmware needs to be modified like mine before it can be used.

Schematic analysis :

    The first is the power supply part, which uses a commonly used Android interface, through a self-locking button (not used in the actual product, directly shorted), and then two input filters to filter out high-frequency interference and stabilize the voltage. This is all based on data It comes from the manual, and then it is a step-down LDO. The voltage stabilization effect of this AMS1117 is quite good. During the production process, I first tested whether there is output overshoot at the moment of power-on. After reducing the voltage, connect two filter capacitors.

    Then comes the infrared emission part. Due to the insufficient IO driving capability of the module, a triode driver is added. Here, one more LED is drawn. The best effect is to draw three in series. The voltage of one LED is 1.2V, and four 4.8V plus triodes are added. The voltage drop causes the emission effect to be poor, so it is best to use three in series.

    This is the infrared learning part. This part is drawn according to the principles given on the official website. There is nothing to say. The key point is not to forget to add the pull-up resistor.

There is not much to say about the metering and relay parts. Just don’t forget to add a freewheeling diode to the relay . Also note that the current-sensing resistor must choose the appropriate power according to the current you are testing, otherwise it may burn out. Safety needs to be paid attention to when using strong electric current.

The core part, WiFi module. This part is drawn based on the pipe network diagram and configuration firmware. Two indicator lights are left, a WiFi distribution network indicator light, and a relay switch indicator light.

###The picture below is the configuration page###

    After drawing the schematic diagram, it is time to convert it to PCB. Of course, before this step, you need to check whether there are any errors in the schematic diagram. For the pcb diagram, I referred to the design of Taobao WiFi remote control and designed the pcb into a circle. The 8 infrared transmitting tubes use the matrix function to be evenly distributed around the edges of the board. In this way, I feel that the air conditioner can be remotely controlled from any angle without having to deliberately Go for the angle. There are two LED indicators left on the board to display the working status of the module. Finally, after I finished laying out the wiring, I concluded that when wiring a circular PCB, the main components must be aligned along the X-axis or Y-axis, otherwise the angle of the wiring will be very tricky during the final wiring!

###3D preview rendering###

2020,11,29

    I checked Tuya’s official website today and the logistics information has not been updated yet. My PCBs have all been shipped today. long wait. . . . . .

2020,12,1

   I received the module today and the PCB yesterday. After receiving it, I stepped up the soldering. My method is to solder the power circuit first, then test whether the voltage is stable, and then solder the module. The reason for this is that once I used HT7333 to make a drop. Pressure, the result was 5V at the moment of power-on, which directly burned my NRF24L01. Later I learned the lesson and tested the power supply first before installing the module. After everything is welded, the problem comes. The network distribution part went very smoothly, and then came the most important infrared remote control. This part was difficult to debug at first. So I started watching tonight’s live broadcast, but I didn’t learn anything. Basically, I was working on the circuit board while looking at it. It keeps getting stuck on infrared code matching. I didn't look carefully here, thinking that there would be an infrared signal output when entering this page, but there was no output. I also brought out the logic analyzer and directly tested the IO and found that there was no output. The final reason was that there was no click here. Alas, this step wasted three hours. Of course, I tested the infrared learning function during the process, and it was able to learn. There was also an output signal when testing the IO, but the infrared light did not light up. I struggled with this problem for half an hour. When the live broadcast was over, I suddenly thought that it might be a packaging problem, so I immediately looked at the data sheet. Alas, the packaging was really wrong, so I immediately flew out the wires. After testing, the infrared light has a signal and the air conditioner can be controlled. With the output, the thinking becomes clear instantly. Open the mobile APP and experiment with the remote control function again, and find that you need to press the buttons in those boxes to have output. After testing for a while, the matching is completed. At this point, the WiFi remote control is completed. The next step is to make a shell.

    As it is made tonight, the empty and unsoldered components are used for current detection and are reserved for subsequent development.

This is what the triode flying wire looks like. Later, the test found that the 5v driving voltage of the four infrared lights was not high enough, so one of the LEDs was short-circuited. The actual test results are still very good.

2020,12,3

    Today I made the print file of the shell. The three-legged cat's modeling skills were difficult to draw the shell. Later, I found that the distance between the USB ports was wrong, but I cut it with a knife and it was fine.

final renderings

Instructions:

    After the mobile phone is connected to WiFi, open the Tuya APP. After the WiFi remote control is powered on, press and hold the network distribution button until the WiFi indicator light flashes. Then click Auto Search for the device in the APP. When the WiFi indicator light is always on, the device will be displayed on the phone interface. Click to add a device, and then you can configure the required functions.

2020, 12, 3---22:14

I couldn't connect to the Internet just now. I followed the prompts and used hotspot mode to connect. I asked customer service and said there might be a problem with the network. In addition, this module only supports 2.4G WiFi! ! !

2020,12,4

                                                                                                                                                                                                                                                                               +

       Demo video presented

         https://www.bilibili.com/video/BV1si4y157Fv?share_source=copy_link&share_medium=iphone&bbid=Z8478A8ABDF9651246749D1E917F4FF586E6&ts=1607079875   

2020.12.5

    The transistor package has been changed, and the proofing version 2.0 PCB can be used directly.