Pila Codex
The "Codex" is a module to add programmable modes to your Pila flashlight. It is available for the GL2, GL3 and GL4 models and works with either incandescent lamps or the LED dropins, luxeon or Cree. The module works regardless of the battery types used so you can still use primaries or rechargeables. The Pila LED tailcaps can't be used with the Codex module, it only works with the tactical clickie switch.
The codex is installed between the bezel and the battery tube. It has 4 programs "a,b,c,d" that you can modify. Each program consists of a series of frames (up to 9 frames per program). Each frame defines a brightness level (0%,25%,50%,75%,99%) and a duration (from 0.0 to 9.9 seconds). When the program is activated frames are run in sequence re-starting with the first frame after the last one is played. So for example a strobe is a 0.1 second 99% frame followed by a 0.1 seconds 0% frame. A locator beacon can be a 25% 0.1 seconds frame followed by a 0% 9.9 seconds frame. Etc. There is a built-in SOS mode that doesn't take a program and can be used at any time. There is also a "bypass" mode that means "no program" to use the light at 100% brightness. After programming you can cycle through programs and bypass mode clicking the button in the codex module.
The codex also adds a battery indicator and automatically dims the light if the battery is low to preserve runtime. The module also remembers the last program used and turns on in that program the next time the light is used.
We found the codex very interesting but very limited for its size and price, 4 programs are not enough if you want 4 brightness levels you can't have any other programs strobes anything. The programming is also limited forcing you to create repeating sequences, many ideas we had in mind like a light to read at camping that auto turns off after a few hours or keeps blinking in beacon mode are not possible. The self-start test that makes the light blink destroys momentary operation and the 99% flash is annoying specially if you wanted to start the light in a low brightness mode.
So the idea is brilliant the execution has some flaws. You can read more and order ($73 for the GL2) from JSBurlys Flashlights.