Good progress today on driver!
I had some problem when I notice small short on one component, so I desolder and carefully resolder. I advise checking with multimeter to make sure no short!
So this took a bit extra time but lucky I catch mistake because components are very small!
I use good idea from moderator007. I do not have thick copper wire, so I use cable terminal and make my own by cutting out plastic, and flatten both side using hammer and careful sand paper.
The final is about 5mm long and 4.5mm wide. I solder this on pcb with hot soldering iron.
Programming the 841 - I use pogoprog and ATMEL ICE programmer from friend, and use Atmel Studio 7 to program fuses and hex file.
This lucky had no problem and everything was OK! So after that I carefully solder driver to led pcb and add some thermal paste between led and brass holder of Convoy S2+.
I use plastic butterfly piece for prevent short to aluminum reflector.
Finally I test and it WORKS!! Very happy that carefully soldering produce working result! Very bright!
I cannot believe I finish building driver finally!!
Next I wait for pcb for tailcap to finish S2+ flashlight!
Question - do anyone have recommend battery to use? I have LG Brown 18650. Hoping to test flashlight much more!