# Sixth Lichuang Electric Competition# Engineer’s weapon (not)-voice-controlled soldering iron

1. Introduction to project functions

The voice control electric soldering iron T12 is convenient for controlling the temperature by voice when debugging the soldering board. Especially when both hands are free, there is no need to manually adjust the temperature to facilitate soldering and improve efficiency.

It can be said to be a siege lion weapon (crossed out).

Using HK32F103C8T6 (STM32F103C8T6) and Qiyingtailun voice chip CI1102 (CI-B02GS03T (Tuya IOT) module) C2759837.

Use PD power supply, or DC port, 24V-12V (low voltage will heat up slowly). OLED display.

2. Project attributes

First published, original.

The program source code is completely open source.

3. Open source agreement

GPL3.0

4. Hardware part

1) CH224K decoys 20V, and it is recommended to use a PD charging head above 45W. It can barely be soldered using an 18W (12V 1.5A) QC charging head.

2) J3 is the T12 handle input, 1, positive. 2, negative. 3. Sleep. 4. Ground.

Two PMOS Q1 and Q3 control heating, leaving a margin for power. T12 can actually be used all the way.

The T12 soldering iron tip is composed of a heating wire of about 8 ohms and a thermocouple (N-type thermocouple) connected in series. The thermocouple voltage is collected in the heating gap, and the U8.1 differential amplification is 100 times sent to the microcontroller AD for processing.

D9 clamps the input voltage when T12 is heated to avoid exceeding the op amp input voltage.

R43 is the T12 current sampling resistor. Similarly, the U8.2 differential is amplified 20 times and then sent to the microcontroller AD for processing. Used to detect the status of the soldering iron tip, whether it is open circuit, short circuit, and overcurrent protection.

The GS8552 op amp (C157716) is used here, which is cost-effective, has rail-to-rail input and output, and has a small input offset voltage, so it is suitable for use here.

3) NCT is thermocouple cold end compensation, actual temperature = NTC temperature + thermocouple temperature.

Input voltage collection, providing overvoltage and undervoltage protection.

TL431 is the reference voltage ME431 (C85795) 2.5V.

4) The MCU uses HK32F103C8T6 (or STM32F103C8T6), (the price is too expensive now).

5) OLED uses 12864 OLED screen of SSD1306 controller and I2C interface.

RTC uses PCF8563, I2C interface.

6) Use DCDC to step down the voltage to reduce heat, use 5V for the voice module, and use Hangshun HK7533 to step down 3.3V for the microcontroller.

7) The voice module uses Qiyingtailun voice chip CI1102 (CI-B02GS03T (Tuya IOT) module) C2759837.

8) Use CH340E to serial port for debugging, which is convenient for debugging.

5. Software part

When using (CI-B02GS03T (Tuya IOT) module) (CI110X_SDK_ASR_Offline_V1.4.5), you need to change the MIC settings in the SDK, as shown below.

6. BOM list

7. Contest LOGO verification

8. Demonstrate your project and record it as a video for uploading

---------------2021.8.2----------------------

The basic functional verification has been completed, the bug writing is a bit messy, and the program is still being improved and optimized. . . . . .

The front panel PCB has not arrived yet, let’s assemble it first to see the effect.

---------------2021.8.2----------------------

The firmware of the voice module has been updated to avoid the problem that only one of the two pronunciations of "二百度" and "二百度" can be recognized.

Solved the problem of occasional misplacement of wake words. The firmware and firmware production files have been uploaded as attachments.

The program is completely open source, and STM32 is currently used. MDK5.

I replaced the MIC with better sensitivity (the MIC used in Bluetooth headsets) and re-recorded the video.

For a clear version, please see https://www.bilibili.com/video/BV1eg41177YB

---------------2021.8.7----------------------

The front panel was installed, the aviation plug was welded, and the program was updated.

Add soldering iron sleep, use the vibration switch of the handle, sleep without action for 100S, and reduce the temperature to 160 degrees. It can also be controlled by voice.

The soldering iron temperature smoothing filter has been changed to stabilize the temperature and not jump around when the temperature is high.

A simple dynamic temperature display bar has been added.

Added a program to play local announcement sound.

Added power switch function.

Added the function of playing bad apple (useless). Play at full speed, no time adjustment. It seems that the voice module cannot accommodate such a long audio, so no audio is added.

The video was recorded again. 

---------------2021.8.8----------------------

After some research, I found that the audio file can be placed in the voice module. I updated the bad apple video, adjusted the playback time, and added audio.

https://www.bilibili.com/video/BV18P4y1x7jv

I made some minor changes to the program and uploaded the source code.

---------------2021.9.5----------------------

Added time setting, press and hold the left or right button and then turn on the phone to enter the settings.