Alternative firmware for cheap ($6) 12 volt spot welding batteries based on PIC12F microcontroller (PIC12F683 or PIC12F1822 is supported)

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The original firmware of the unknown microcontroller has six modes from 5ms to 20ms point delay (if you have wires longer than 30cm, the delay must be longer than 20ms - this is a significant drawback and is why this firmware was written) The pinout of the original microcontroller in this spot weld is compatible with the PIC12F family of 8 pin microcontrollers.

• Alternative firmware, what is added:

  • This firmware also has six modes from 5ms to 20ms, but on the 6th mode you can enter the sub-mode in which you can adjust the last value from 20ms (in +3ms steps) to 50ms - this is necessary in case you have a long wire or you want to solder a more current. In the sub-mode the selected mode is saved and in the future (even after power-off the module) it is enough just to switch to the sixth mode.
  • By default the last chosen modes is not saved (in case the board is power-off), but this option can be enabled when compiling/recompiling the firmware SAVE_LAST_MODE.
  • Buzzer beeps only when switching mode and only during welding. Unlike the original firmware, the buzzer does beep a certain number of times in proportion to the selected mode (it is annoying), but this option also can be enabled when compiling/recompiling the firmware BEEP_CHANGE_MODE.

• Short Press Button - switch modes

• Long Press Button on 6th mode - and Short Press press up to theen times - then again Long Press Button to save 6th mode in this settings.

• Power-up with Pressed Button - reset EEPROM

Link to this model of spot welder: https://www.aliexpress.com/item/1005006198373222.html

How to flash this microcontroller without the required proprietary programmer using Arduino: https://community.alexgyver.ru/threads/arduino-programmator-pic-ov.4279/