About Thesas o

Thesas o is an open source and open hardware Mod designed and developed by Thesas.
It is based on Teensy 3.2 with the Arduino toolchain.
Software version 1.0 offers the choice of voltage, wattage and temperature control, a 4 click locked mode and a sleep mode. An overload protection is implemented and arbitrarily set to 80W. If output monitoring detects a higher output then 80W, an overload message will be shown and Thesas o will enter sleep mode.

Choose the right battery

- for low power (up to 30W) e.g. a “Samsung INR18650-35E”
- for low and medium power (up to 50W) e.g. a “LG INR18650HG2”
- for high power (above 50W) e.g. a “Sony Konion US18650VTC5A”
Insert the battery with negative pole at bottom (but don’t worry, Thesas o is reverse polarity protected).

User interface

Thesas o has a 3 button user interface.

The fire button (located above the OLED display) is used to
- fire Thesas o, by pressing this button
- enter the wire selection menu, by short pressing the button 3 times
- enter the locked mode, by pressing the button 4 times.

The up and down buttons (at the bottom of Thesas o) are used to
- change temperature in temperature control mode
- change voltage in “NC” mode

Press the fire button and the up or down buttons simultaneously to
- change the maximum power (W) in temperature control mode
(by higher power the desired temperature will be reached         faster, but a bit less accurate)
- switch from voltage control to power control (W) in NC mode 

The wire selection menu
By pressing the up and down buttons you can chose between
NC (“
Not temperature Controlled” use this for Nickle-Chrome or Kanthal), Ni (Nickel, Ni200), Ti (Titan), NF (NiFe48 ), V2 (SS V2A), V4 (SS V4A) mode, or measure and set the resistance of the wire. By pressing the fire button you apply the selected mode and leave the wire selection menu.

Locked mode: Pressing the fire button four times, with less than 0.4 seconds between presses, will cause Thesas o to enter the locked mode. In locked mode, Thesas o will not fire and the output power will not adjust accidentally. To exit locked mode, press the fire button 4 times.

Sleep mode: around 25 seconds after releasing a button, Thesas o goes to sleep mode (with a power consumption of around 110uA, so 2000mAh will preserve for more than 2 years), but Thesas o will wake up and will be ready for the next vape very quickly.

The micro USB connector

might be used to charge the battery, to monitor the Thesas o steering, or to reprogram the Thesas o firmware according to your needs. 


Quick Reference Guide

·           Fire button

o  long press: fire Thesas o

o  3 short clicks: wire selection menu

o  4 short clicks: enter/exit locked mode

·           Up and down buttons

o  “TC” mode: change temperature

o  “NC” mode: change voltage (V)

·           Fire button and up or down button simultaneously

o  “TC” mode: set maximum power (W)

o  “NC” mode: set power control (W)

·           Wire selection menu (use up and down buttons to choose, press fire button to apply)

o  measure and set the resistance
(do this after installing a new coil)

o  NC (No temperature Control) mode
use NC mode for Nickle-Chrome or Kanthal

o  Temperature control (“TC”) modes:
         NF (NiFe48 )     
         Ni (Nickel, Ni200)
         Ti (Titan)
         V2 (SS V2A)
         V4 (SS V4A)


If you want to contribute

or if you have an idea how to improve the Thesas o, (over 70% of the program memory is still free), you can post your idea here: http://www.dampferforum.ch/index.php/Thread/1858-DIY-TC-Mod/
or send a mail to: