Smart desktop computer switch card based on [Tuya Smart] IoT platform

What this project is producing is a simple IoT desktop computer switch board, which is equipped with a dual module of WBR3 WiFi and Bluetooth. You can use your mobile phone to connect to Tuya Smart’s IoT life platform to remotely control the desktop computer. switch machine, and also has functions such as timer switch.

1. Basic functions

1. Remotely realize real-time power on and off of desktop computers via mobile phone

2. Remotely realize scheduled power on and off of desktop computers via mobile phone

2. Device selection

WBR3 WiFi Bluetooth dual module

Directly use the official module of Tuya Smart as the main control, implement it with zero code, slightly adjust the firmware, and splice the circuit diagram in Lichuang EDA, which is convenient and fast!

Attiny85 small MCU

First, the cost should be as low as possible. Second, the same PCB layouts should be compatible with several MCUs of the same series (Attiny25/Attiny45/Attiny85, etc.). Third, the firmware supports writing using the familiar Arduino IDE, so this small MCU was chosen.

ME6210A50PG (for use in high voltage power supply environment, the entire power circuit is optional)

Convert the external 7-12V input voltage to 5V. The output 5V is very stable with very small deviation, so I chose this voltage regulator chip.

AMS1117-3.3 (for use in 5V power supply environment, the entire power supply circuit is required)

Convert the Micro USB input 5V voltage to 3.3V. The output 3.3V is very stable with very small deviation, so I chose this voltage regulator chip.

ME2108A50PG (for use in 3V power supply environment, the entire power circuit except ME2108A50PG is required)

Boost the PCIE interface 3VSB to 5V. The output 5V is very stable with very small deviation, so I chose this voltage regulator chip.

Button(SW2)

During the design, I added a button to facilitate WBR3 network configuration and reset (although Bluetooth network configuration is also possible, it is said that you have to wait 15 minutes after powering on, which I can't stand).

interface interface

PCIE gold finger: easy to assemble and draw power, so choose it. J2: To facilitate the firmware update of Atmel MCU (Atinny85), one is placed on the circuit. J3: It is convenient to update the WBR3 firmware. I also want to use a serial port to realize the communication between the module and the computer and facilitate the debugging of the Tuya WBR3 module, so I placed one on the circuit.

3. Welding

Although I am a veteran in welding, 0201 will not take it seriously. But considering that there are not many components used, there is no need to find faults for myself, so during the PCB layout, no matter what components on the board, I chose the smallest package size of 0603 or above, so the entire welding process went smoothly. In addition, in order to use this card as an MCU burning device, I specially added a socket to the MCU (U2), which is perfect, as shown in the picture above:

4. Debugging process

When powering on and debugging, everything went smoothly, because many of the electrical appliances I purchased at home were Internet-based, such as air conditioners, sockets, power strips, rice cookers, soymilk makers, etc. The network distribution process was similar.