907 Portable Soldering Iron Based on Techbuilder/ASCAS Design

After trying to build a portable soldering iron based on the electronoobs V1 design, I wondered what if I could build the same soldering iron but based on the techbuilder design? So I gave it a try, and here's the result. With the help of chatGPT to modify the arduino program, I managed to create a portable version of the 907 soldering iron made by techbuilder.

Assembly video: Youtube

Component & part list:

SMD:

1. 3X 1206 100nF capacitor
2. 2X 1206 10K resistor
3. 1X 1206 3.3K resistor
4. 1X 1206 2.7K resistor
5. 1X 1206 470R resistor
6. 1X 0805 6V 0.35A PTC resettable fuse (bridge solder to bypass it)
7. 1X SS36 schottky diode
8. 1X M7 general purpose diode
9. 1X TO-252 IRLR024NTRPBF N-channel MOSFET
10. 1X SOIC-8 LM358 OpAmp
11. 2X 220uF 10V D8X6mm
12. 1X CSTCE16M0V53-R0 16MHz Ceramic resonator (salvaged from arduino nano)
13. 1X Atmega328P-AU (salvaged from arduino nano, upload the firmaware before desolder it)

THT:

1. 1X MP1584EN (set output to 5V)
2. 1X OLED 0.91 inch
3. 1X A1321 Heating element
4. 1X DC jack 2.1X5.5mm 2 pins
5. 1X 30mm 10K slide potentiometer (example: Bourns PTA1543 series)

Others:

1. 19V 3A power supply (theoretically can be pushed to 24V)
2. 907/936 soldering iron handle

All components are purchased locally due to government restrictions on import policies from foreign e-commerce, especially AliExpress.

this is my first design experiment with KiCad software. Printed with JLCPCB service.

Gerbers, schematic, firmware, etc: Google Drive

i'm using PLA+ for the main body (grey) and ABS for the lock (black). kinda hard to assemble beacause ABS shrink more than PLA+, but i don't want the PLA to melt because the heat. so i add some fiberglass insulation tube to reduce the melting risk.

3D case: Google drive, GrabCAD

The components I chose were fairly easy to solder manually. don't forget to prepare the required items like flux, solder wick, and tweezers.

Upload the progam to an arduino nano, then transplants the Atmega328P MCU to the custom PCB. the MCU is located under the OLED 0.91. So, don't put it upside down when soldering it.

Firmware: Google drive

Quite good for manual soldering. even though i have a hot air station, my solder paste kinda low quality and i didn't order the stencil to reduce the cost.

No need screws or bolts. easy to dissamble, just slide out the two caps one both sides.

I'm very happy with this project. I don't need to carry a thick and bulky soldering iron. This soldering iron fits in palm of my hand. The only issue is the large power adapter. Perhaps this can be fixed by modifying it to fit a USB-C PD and a 65W adapter.

Documentation: Google drive