Sofirn SC31 Pro & Anduril2

I started buying flashlights a few months back. I started with an Astrolux FT03 which comes with Narsil installed. Anduril is another widespread firmware for flashlights with more features than Narsil. There is even Anduril2 in the work and I decided to install this version on my FT03.

A few weeks later, I decided to buy another smaller flashlight. Looking at reviews, the Sofirn SC31 Pro sounded like a great choice for me. It comes with Anduril. Since I had Anduril2 on my FT03, I looked at how to flash it on the SC31 Pro.

I found this post which sounded promising. As you can see here, you can access the ATTiny85 when removing the button. However, things are very very tight. Still, I decided to give it a try.

I bought some pogo pins and 3d printed a support for them:

The resolution of my 3d printer is barely good enough to have something usable. But that did the trick. I glue the pogo pins with CA glue:

I then soldered wires to the pogo pins and installed the device on top of the ATTiny85. This was clearly the most critical part. My 3d print mount is not optimal and I had to hold it in place using the wires. I double checked visually that the pogo pins were not touching 2 pins and were more or less correctly placed.

I plugged in my USBasp and could successfully access the ATTiny85 with avrdude. Flashing Anduril2 was then just a matter of a minute.

Based on the comments I found on budgetlightforum.com, Sofirn is using the same configuration for all its flashlights so I used cfg-sofirn-sp36.h to compile the firmware.

After flashing, I disconnected the USBasp, put in the battery and tested that everything was fine. I now have both my flashlights on Anduril2.