ESP32 heating stage

The ESP32 heating station uses TYPE-C fast charging decoy power supply. By reducing the internal resistance of the heating plate and PWM control MOS for constant current driving, it solves the problem of the copper wire resistance of the PCB heating plate increasing as the temperature increases, resulting in the inability to operate at full power. At the same time, it uses The high-power test pin supplies power to the heating plate, simplifying the assembly process.
 
Function introduction
1. The main TYPE-C interface is decoyed to provide power through CH224K fast charging, supporting up to PD100W (20V/5A)
2. The side TYPE-C interface is mainly used for USB download program
3 PT1000 platinum thermal resistance temperature measurement range: -50℃~300℃
4. 0.96-inch ST7735 160*80 display screen displays various parameters
5. 4 touch buttons for function switching parameter settings and an EN reset button
6. Supply voltage and current measurement ESP32 C3 chip internal temperature measurement buzzer, etc.
7. Supports constant current threshold settings for different decoy supply voltages
8. Heating plate size: 8cm*8cm aluminum substrate
9. Has constant temperature heating mode and reflow soldering mode
 
function mode
1. Power on and enter initialization The page setting key selects the corresponding working mode. The switch key selects entry or exit.
2. Low-temperature reflow soldering mode: low-temperature solder paste reflow soldering mode. After the switch key is entered, the setting key controls on or off
. 3. Medium-temperature reflow soldering mode: medium-temperature solder paste reflow soldering mode. After the on/off key is entered, the setting key controls on or off
4. High temperature reflow soldering mode: High temperature solder paste reflow soldering mode. After the on/off key is entered, the setting key controls on or off
5. Constant temperature heating mode: After the on/off key is entered, the setting key controls on or off the heating mode. The minus key adjustment requires a constant temperature
6. Constant current setting mode: after entering the switch key, select the corresponding voltage range with the setting key and plus or minus keys to adjust the maximum constant current
 
Program download
1. This program is based on the Arduino IDE development source program and dependent libraries in the attachment There are compiled and exported burning files 
2. Compilation environment: arduino1.8.19 esp32_package_2.0.53. Before compiling, you need to install the relevant libraries and select the corresponding development board chip settings
4. When the chip downloads the program for the first time, the USB will not be recognized and you need to pull down the P9 pin (Press the plus button) and then press the EN reset button to force into the download mode.
 
Hardware assembly
1. The main control board is an ordinary RF-4 material 2-layer board with a thickness of 1.6mm. The heating plate and the heat shielding plate are both aluminum-based single-layer boards. Thickness 1.6mm  
2. The ESP32 heating stage mainly consists of: main control PCBA + heating plate + heat insulation plate + bottom plate (empty main control board) + test pins + PT1000 + M2 copper pillar screws + thermal insulation cotton
3. There are two test pins Model: (P113-H3.0-M2)*2 For large heating table solution (CSPA-6G/2S)*4 For small heating table solution, just choose one and use it
4. Small heating table assembly solution Thermal insulation It is not easy to use more insulation cotton. Parameters of connectors: single-pass copper pillar (M2*4+3)X8 + double-pass copper pillar (M2*3)X4 + flat head screw (M2*3)X8
5. Large heating table The assembly plan has a relatively high height and therefore a large volume. Connector parameters: single-pass copper pillar (M2*3+3)X8 + double-pass copper pillar (M2*20)X4 + flat head screw (M2*3)X8 + (M2 nut) X2
6. The thermal insulation cotton uses aluminum silicate ceramic fiber fireproof cotton. You need to use scissors to cut it to the appropriate size.
7. There is a fan drive pin + FAN- reserved. It is only used in large heating table assembly solutions. If you use a fan, you don’t need to use an insulation cotton. Hot cotton fan model: 3007 5V DC cooling fan 
 
Notes
1. The power supply uses PD100W fast charging power supply by default. PD65W power supply cannot meet usage scenarios above 200 degrees (barbecue). 12V*1.5A/18W power supply can only heat a cup of water
2. The maximum setting temperature range of the software: 0℃~300℃. Because the heating plate is an aluminum substrate, it is not recommended to be used above 200℃ for a long time, and it is best not to open it to 300℃. 
3. Reflow soldering mode does not have a forced heat dissipation device after the reflow soldering heating is completed. When entering the cooling mode, the heat dissipation speed based on air convection is too slow to keep up with the temperature curve. You need to wait for a while before the buzzer prompts the end
. 4. The software of this project is not perfect yet. I will improve it after I learn LVGL  
. 5. The component parameters are based on the schematic diagram. The software and hardware information related to Taobao for the components that Jialichuang does not have are in the attachment
6. This project is CC BY-SA 3.0. If the open source project requires mass production for commercial use, it must be authorized by the original author. It is free to sell for personal use and <100 sets for commercial use.
 
Physical display