Hello, I'm andreasvb. Vaping helped me quit smoking since 2011. I designed this form factor of a DNA 40 Mod, because I really missed it.
Then DNA40 sized chips did not evolve anymore, so I developed a Teensy 3.2 based DC-DC converter with all options of temperature control, voltage control and power control. I made it open source, so you can adapt the steering perfectly to your needs.