Portable mini heating table V2.0

 The second version will be more practical, beautiful and stable. Similarly, all modules in the second version will be open source and can be customized, including STM32 master control and PD protocol modules. The second edition will also have more comprehensive information.
The development environment
uses KEIL5 and is developed based on the STM32F103C8T6 or C6T6 standard library (in actual testing, this version of the program is compatible with C8T6 and C6T6A).
Progress update:
March 15, 2022. 
  The program framework has been written, and the menu and UI framework have been built. The first version of PCB is being drawn. On
March 20, 2022, 
  the fast charging protocol module based on CH224K has been experimentally completed. Can output 20v, 15v, 12v, 9v voltage.
On March 31, 2022, 
  the PCB and program were basically completed. Start sample testing. The PCB has been received
on April 5, 2022 
  , and testing of stability and actual usage has begun.
  The basic test passed, there are no major problems in the program, some minor bugs have been solved, the PID has been roughly adjusted, and the OLED refresh rate has been optimized to make the animation smoother.
  Optimized the reading of the encoder, making the reading more accurate and stable. In terms of hardware, due to the difficulty and cost of production, the next board drawing separates the MCU main control and the board and uses pin headers to connect them. This can reduce the difficulty and cost of production.
  After half an hour of constant temperature testing at 200°C, the MOS was about It is 40+ degrees, and LDO generates a lot of heat, about 60 degrees. Heat dissipation needs to be enhanced in the future. The MOS tubes should be managed together to reduce heat generation. The LDO is equipped with a heat sink.
On April 6, 2022, 
　the new PCB has been drawn, and this version is expected to be a stable version. It solves the production difficulty, cost and heat dissipation issues. The 3D shell drawing is completed.   The v2.0 PCB has been verified on
April 10, 2022  , and the 3D shell is on the way. Officially released on April 17, 2022  ! ! ! ! Summary MCU: STM32f103c8t6 (or c6t6A)  Power supply: PD protocol includes 20v, 15v, 12v, 9v (20v is recommended) Chip: CH224K Control: Encoder SIQ-02FVS3 Display: 0.96-inch OLED (IIC) Heating plate: Aluminum substrate (approx. 6.8Ω) Temperature detection: K-type thermocouple + MAX6675 Function introduction The heating stage controls the temperature through PWM pulse width modulation. Main interface: (1) Display parameters: The upper left corner displays the current temperature, the thermometer icon on the left represents the current temperature level, the battery icon represents the current power supply voltage, and the right side is like a pull cord for mode switching display. The lower slider and the temperature on the right are to set the target temperature. (2) Control: You can set the target temperature by scrolling the encoder left and right, and press the encoder to switch to the preset temperature mode with one button. Menu interface: (1) Voltage: Control the power supply voltage. (2) Temperature: Set the temperature step. (3) Setting: Set the temperature of the three modes. (4) Personalization: Not used yet. If you have any desired functions, you can put them here. (5) Return: Return to the main interface. Demonstration video (if you think it is good, please like and vote, you know~) Portable Heating Table V2.0 Open Source Mini Digital Display Heating Table_bilibili_bilibili The overall appearance of the 3D shell can be made of nylon or ABS, I am The nylon material used is made by Jiali Chuang. The texture is really good. The project has been successfully exported. For details of the PCB project file, please see attachment 2. Then the PCB plate making file and BOM have precautions  in attachment 1 (1) The mos tube generates less heat. , you don’t need to install a heat sink (add it if you can), LDO generates a lot of heat, so you need to install a heat sink, and plate the window part with solder to enhance heat dissipation. (2) The aluminum substrate is conductive, so during production, be careful not to contact the two wires connecting the aluminum substrate with the aluminum part of the aluminum substrate. (3) Pay attention to the positive and negative polarities of the K-type thermocouple. (4) Be careful not to use the heating table at high temperature for a long time. Generally, 200 degrees is enough to melt tin. In actual tests, there is no problem in continuous use at 200 degrees for 20 minutes. (5) Pay attention to distinguish the 8M crystal oscillator type of the STM32 core board. If it is a passive crystal oscillator, the new STM chip may cause the passive crystal oscillator to not vibrate and not work properly (of course there is no need to buy a brand new one, the new one is too expensive. Buy a refurbished genuine c6t6A for only 7 yuan each) (6) The screws and studs used in assembly are all M2 models.