Excellent thread! In fact, I registered on this forum just so I could post here ;) I want to thank all of you for the information so far.
I am planning on buying the equpment needed in order to program ATtiny13 chips to use in a driver for a D cell Maglite runing (for now) an XP-G. Here is what I plan to order or have ordered:
Drivers:
DX 7135 - http://www.dealextreme.com/details.dx/sku.6190 (probably a crapshoot to see if I'll get a good one with the correct MCU)
SB 7135 - http://www.shiningbeam.com/servlet/the-133/3-dsh-Mode-Regulated-Circuit-Board/Detail (not sure about the solder bridge I see between pins, but I'll try it)
Programmer:
USBtinyISP - https://www.adafruit.com/index.php?main_page=product_info&products_id=46
Cable:
SOIC 8 pin - http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=400171159037 (as suggested by a member here - thanks!)
The purpose of doing this is mainly to have some fun, but it seems the majority of the 7135 constant current multi-mode drivers out there have a UI that I really dislike. Because they only have an ON and an OFF state, controlled by switching the power from the battery, they have that funky "3 second memory" function (because there is no way to know how long a light has been off). Now, I would like to have the benefits of brown-out detection with a capacitor (I believe I'm saying that right) so that the controller knows when a user clicks the light off and then back on in a split second. However, I can't seem to find a good driver that has that ability, at least without other drawbacks. Currently, the Solarforce low-voltage drop-in I have in front of me has a great UI. You can turn it on for a split second, and as long as you wait a second or two before turning it on again, it will not switch to the next mode. Also, if the light has been on for a few minutes, you can switch to the next mode just by tapping the reverse-clicky once, instead of twice like the drivers I listed above. However, the PWM is really bad on it.
So, my goal is to hopefully be able to program whatever UI I or a friend might like to have, at least within the limits of the hardware setup. I will need to be able to do this with pre-mounted controllers, such as on the drivers I purchased. In the future however, I might try to build a driver board myself, but I doubt I'll get there. I've never programmed in C before, and I was initially turned on to the PICAXE chip as you can program in BASIC. However, being that the Atmel tiny chips can run at lower voltage and seem to be more widely available on pre-built drivers, this seems the way to go.
Anyways, I just wanted to say thanks and warn you that there will probably be a lot of questions coming your way. I've hardly soldered much in my life, let alone try to work with a microprocessor :)
- Jon