Nice work, caesar.
Yeah, the micro I was thinking of is the sot-23-6 PIC10Fxxx. It would only supervise the charge controller chip, by suspending the charge when vaping for a few seconds, then resuming the normal charge cycle. Might confuse the charger chip with a high amp drain on the cell during a charge. But the PIC would mainly allow a tact switch to trigger the vape without passing an amp or so through the switch itself.
Kina, I don't know your touch switch circuit, but could it be done in software from the micro (without A/D)? A touch and a tactile switch would be a hell of a safety interlock.
I'm not trying to pitch the micro, because the board would still be great without it. The programming for this simple of a task, though, wouldn't take more than an evening. It's primary drawback would be the increase in board complexity.
Even at this simple of a level, though, a controller could do some tricky things. Like a variable toke timer. 'Double click' the vape button and the micro flashes the LED twice to tell you it's ready for input, then hold the button down for however long you want for a timer cutoff. The chip times that button press, writes it to flash memory, and from then on limits a toke to that length of time. Etc, etc. Again, the purpose of the board is to squeeze the charger inside the box, make the button and led mounting trivial, and still leave room for half the atomizer to be protected inside the box.
Oh, I took nico's radio shack 901 connector (actually digi-key) and quarter-twisted the solder tabs. Makes a nice way to solder it to the pcb and hold the connector in place while you goop some epoxy around it to fix it in place. The throughhole pads for atomizer wires could be centered to facilitate this idea.
