【Training Camp】Make the complex into simplicity (finance) is under my control

https://oshwhub.com/12344321A/sui-xin-suo-kong_copy     This link is for later reference to the circuit diagram provided by Tuya official website. If you want to make it, it is recommended to use this board. Both VWRX2 and WB3S modules are available.

 Official website introduction video https://www.bilibili.com/video/BV1sp4y1i7bS  

 Introductory video  https://www.bilibili.com/video/BV1CK411K7nK                    

 Practical training for controlling household appliances. Made based on Tuya smart module (zero code)

The project is based on Tuya VWXR2 module , which can voice control a variety of home appliances with infrared remote controls. It comes with a learning function and is equipped with 1 infrared receiving tube and 7 infrared transmitting tubes. It is a universal remote control that can emit infrared in all directions.

Features:

1.   Firmware development-free

2.   No APP development required

3.   Omnidirectional remote control

4.   With learning function

5.   USB uses micro USB because almost every family has an old Android phone data cable. If you don’t have one, it’s cheaper to buy one.

6.   To prevent overturning, I introduced excess IO on the PCB and configured an MCH340C for secondary development.

Exterior

The appearance is inspired by the God of Wealth because there are just a pair of buttons and a pair of microphones installed on both sides of the hat (beautiful symmetry). The God of Wealth's mouth was made with slots to put a small speaker, and two teeth were drawn to add a bit of joy (is there any)   ヾ(●´∇｀●)ﾉWow~, and the top layer of solder mask was also added to add a bit more fun . Wealth. As for doing this project, there are too many things in my hometown that need remote control. Since we work outside and don’t come home often, sometimes we can’t tell which one is controlled. That’s why it’s named “Changing Complexity into Simplicity with My Control of Wealth” (wealth is because of the appearance of the God of Wealth) because of this remote control. It may be a bit corny, but this is my personal opinion. If you don’t like it, don’t criticize it. Thank you! ! ! !

Introduction to the main control chip (product creation: Tuya Smart Platform   https://iot.tuya.com )

product description

Tuya IoT voice module VWXR2 is an IoT application WI-FI module equipped with voice wake-up & noise reduction algorithm developed based on XR872AT. It supports WLAN 802.11b/g/n+ARM Cotex-M4F and has built-in 416KB SRAM and 4MB PSRAM , matching Tuya. Cloud voice skills + IoT platform can help customers realize voice portal empowerment for IoT products, and well support low-cost online voice control terminal products.

Features

·         Built-in low-power 32 -bit CPU , which can double as a processor , with a main frequency of up to 380MHz

·         Operating voltage: 2.7-5.5V

·         Peripherals: 9*GPIO , 2*Uart , 2*ADC

·         Antenna support: onboard + optional ipex

·         Sampling rate: 16K/16bit

·         Voice input: built-in 2 -channel audio ADC , which can directly simulate mic

·         Audio output: 1 channel

·         Onboard audio amplifier: supports up to 2.6W

·         Recommended wake-up distance: <=3m

·         Recommended working noise floor: <=60dbC

·         Default voice skills: weather, encyclopedia, calendar, calculator, idioms, translation, music content on demand - supports linear dual MIC , flexible and adjustable spacing ( >40mm ) , flexible ID and MD structural design, easy to integrate

speaker

There is a reserved speaker interface on the PCB . I bought an 8 Ω 2W and connected it directly. You can hear the beep but it is very quiet. (I didn’t read the module instructions carefully.) I will make a simple audio amplification circuit to fill it in later.

microphone

Voice control responds but cannot control the device. However, the voice control function can be achieved by binding Tmall Genie. I still have to check with Tuya online technical support to see if it can be solved. (I would like to mention here that the microphone is recommended by Tuya technical support) and the module’s wake-up word is "Xiao Zhi Butler". I didn’t know it before, so I thought it was the microphone that was welded by me. broken. (I only found this video on December 7th and learned about the need for a wake-up word. After watching the video, there is a document specifically introducing this remote control and a schematic diagram. I was stunned. Why didn’t Tuya give a tutorial link when creating the product? Video link: https ://www.bilibili.com/video/BV1sp4y1i7bS Schematic link: https://developer.tuya.com/cn/docs/iot/smart-product-solution/voice-products/china-online-voice/domestic- voice-infrared-soc-solution/ir2?id=K9lkjrrj5czla）

On December 8, 2020, after creating a work order on Tuya’s official website to report that the voice function cannot control the device, communicate with online technical support and provide the PID (just create the product ID on the upper left side of the product) and the ID on the module, and then activate it through their backend. use.

Infrared receiver

For infrared reception, Taiwan Everlight's patch receiver 38KHZ remote control receiver ( IRM-H638T/TR2 ) was selected to realize the learning function of infrared remote control.

Infrared emission tube

A total of 7 infrared emission tubes are placed in the infrared emission , which emits infrared rays in all directions and is reflected when it encounters obstacles such as walls, thus achieving omnidirectional coverage. (It should be noted here that when welding, do not stick the infrared tube to the PCB. When welding, leave about 5-8mm of the pin to facilitate the adjustment of the infrared emission angle.)

power supply

The power supply USB supplies a voltage of 5V , and then the most commonly used AMS1117 microcontroller is selected to step down and provide a 3.3V voltage output for the system . And added power filtering to the main control and MCH340C .

·         Two buttons, the first one (press and hold for 5 seconds) is used for network configuration function, and (short press) is used to switch the microphone on and off. The second one is used to reset the Tuya module

·         Reserve a speaker interface, which can provide voice prompts after external connection, such as turning on and off the microphone ( the APP can also set specific sentences to announce the weather, etc.)

·         There are 4 LED indicators , two are used for network distribution prompts, and the other two are used for channel communication prompts and will flash when emitting infrared.

Draw schematic diagram

I have no foundation in drawing circuits. This is thanks to the open source projects on the Lichuang open source platform and the ease of use of Lichuang EDA . Thumbs up. Most of the schematic diagrams are drawn with reference to open source projects and the simple schematic diagrams provided by Tuya (I hope Tuya will provide a more complete schematic diagram for DIY enthusiasts to get started) and the application diagrams provided by Lichuang Mall Components. If you want to make this project ( a reminder here: don’t buy components directly according to the BOM list, buy them based on the schematic diagram.) If the original schematic diagram is used correctly, please correct me if the boss sees it someday.

PCB drawing

The appearance is to import a picture and cut it out bit by bit with straight lines on the border. It is too tiring (I hope Lichuang EDA can add the cutout function). I have drawn several boards as a hobby before and most of them failed  - (￢∀￢) σ  , and I also read the EDA usage tutorial, but I am not very clear about the wiring line width and layout requirements. I don’t know where there is a reference manual. The wiring should be as thick as possible and the layout should be symmetrical.

Physical production

An LED lamp bead desoldering station was used for welding . Due to the manual tin planting, the amount of tin was uneven ( here is an idea: for DIY players, many have CNC engraving machines. I wonder if it is feasible to find a piece of thin plastic paper to engrave instead of the steel mesh. ? ) 0603 components tombstone, adhesion, etc. . Therefore, during the soldering process, a toothpick should be used to adjust the amount of tin on the pad and the position of the components. There is also dirt on the surface of the LED desoldering station after being used several times, and the PCB silk screen will turn yellow after welding the original parts. If you want it to look beautiful, you should use a heat gun or soldering iron to solder one by one.

remote control use

Press and hold the network distribution button for 3 seconds to enter the network distribution mode and the two network distribution indicators flash alternately. After successfully configuring the network according to the steps of the Tuya APP during the network configuration step , the APP interface previously created on the Tuya Smart Platform will pop up and give likes and praises. Since I only have time to make it at night at work, I don’t know the functions of the APP in detail , so I will upload my thoughts after using it later.  (๑`･ᴗ･´๑)  

Tuya VWXR2 module application diagram

3D diagram

PCB

Toothpick tin implantation and pasting of components.

I made my own desoldering station, used a thyristor to adjust the temperature, and bought a 500-degree thermometer for the roast duck stove to observe the temperature.

The two indicators on the right side of the distribution network flash alternately.

Physical map

I accidentally discovered that when I send a video to a friend using QQ, the 3-minute video, which is over 300MB, will automatically be compressed into over 60MB. Transfer the compressed video to your computer and then upload it as an attachment. There are also project attachments that can only be uploaded up to 50M (but can be uploaded multiple times), so you need to control the recording time. You can try it if you need it! ! ! !