T12 soldering iron 1.0

The main control is ESP32-PICO-D4, the heating core is T12 heating core, and the soldering iron temperature is obtained by sampling the thermocouple potential through INA190. The 0.91-inch OLED screen displays various information; 2 micro switches operate, and EEPROM saves user settings, TYPE -C interface power supply 65W (20V3A), the handle shell is designed with solidwork and 3D proofed by Jialichuang 3D Monkey

1. Set temperature 0 to 450℃ (there is too little data on the T12 thermocouple indexing table to measure the accuracy)
2. The PWM duty cycle can be set from 1 to 100%. If the duty cycle is exceeded, the PWM duty cycle will no longer be increased.
3. 0.91-inch OLED digital display, with multiple main interfaces and setting interfaces, respectively displaying various corresponding information.
4. The sleep time is adjustable from 1 to 60 minutes. When the set sleep time is not used, the heating will be turned off. Shake the handle or press the button to exit the sleep mode and start heating to the set temperature.
5. Plug in the power supply, automatically read the settings and then automatically heat the sample and display various information.
6. CH224K fast charge decoy can reach up to PD100W. Usually PD65W (20v 3A) is enough for ordinary 5V USB. It can also be used, but the heating is a bit slow.
7. The LIS3DHTR acceleration sensor is responsible for collecting motion postures, responsible for waking up from sleep and providing chip temperature.
8. T12 temperature acquisition uses PMOS to control the power switch to heat the heating core. When the PMOS is turned off, the ADC pin is used to collect the INA190A5IRSWR and amplify the thermocouple voltage signal 500 times.

Program download

1. The program is developed based on Arduino IDE and the relevant libraries are added. Use the serial port module to connect to the download contact reserved on the PCB. Select the EAP32 Pico-Kit model and the corresponding serial port to compile and upload.
2. OTA upgrade I am using the Arduino IDE to directly upload the mode. It needs to be connected through a wired serial port module. First download an OTA upgrade program before downloading the detailed information through the network. Baidu
3. OTA upgrade requires changing the WIFI account and password in the program to your own use or opening a WIFI hotspot and changing it to the WIFI account and password corresponding to the soldering iron.
4. To download, you need to pull pin P0 low and EN low to reset to enter download mode or use a serial port module with one-click download function ( https://oshwhub.com/FJ956391150/ch340c-chuan-kou-mu-kuai)
5. The program and functions are not very complete. I will upgrade it later when I have time. The program and dependent libraries are in the attachment.

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Precautions