Learn to use AVR chips… an 8K Tiny85 is like $.65 in onesies… also a LOT more people are equipped to use them. Sure, they’re not quaint and steam driven like the Zilog chips, but they are rather nice.
Agreed.. The driver would be far more appealing to the mass-market if it were driven by an AVR... or even a PIC..
I was thinking the same thing. I started doing a PCB layout last night. I used an Attiny25 SOIC SSU as a placeholder until I figured out what chip tivo532 was actually using. Give me an hour when I get home (in 5hours 
) and I will have it finished.
Of course if someone beats me to it then let me know so I don't waste my time!
- Matt
EDIT: Oh, and the other advantage to the AVR is that so many people around here program them using the SOIC clips that on board break out points won't be needed which will save a tonne of space on the PCB.
It was tricky enough fitting everything on a 17mm PCB (with a 1mm thick GND ring so only 15mm of usable space either side) especially when you take into account that there are 4 groups of individual signal lines to connect back to the MCU (normally only 1).
Removing the need for programming points makes it MUCH easier.
Good points/suggestions. It just that I’m familiar with the Zilog chip. With the problems I’m seeing members modifying and programming code, I find it much easier on Zilog tools. It’s a complete free windows IDE with a full blown C-compiler/debugger:
1. Edit
2. Rebuild All
3. Download Code
4. Stop and disconnect
I think for me the price is not that much compare to the other parts of the flashlight. And for the advantages to me (maybe not for the others here).
As for the test clip, I think it can be done. Except I opted not to open the driver by having the programming pins accessible on the spring side.
Maybe FastTech can offer the MCU cheaper. 
AVR Studio is the free development environment for all the AVR chips. It is VERY comprehensive and people swear by it. I HATE IDE’s, though. I do all my work outside of AVR Studio except for running the STK500 programmer that I use.
I use the WINAVR compiler. It is a full blown C compiler based upon GCC. WINAVR is no longer being developed and has been superseded by another package (I forget the name).
Pyro,
The $0.65 looks good! But when I look at Digikey it shows $3.61/unit. Any link for $0.65? Thanks.
You like WINAVR, pyro? I found the generated code to be significantly larger and slower than that generated by AVRStudio itself, and a LOT larger and slower than that generated by IAR Workstation. I swear by IAR Workstation for both AVR and STM8..
http://www.digikey.com/product-detail/en/ATTINY25-20SSN/ATTINY25-20SSN-ND/2357360
They're a few cents more if you buy just one.. And this is a link to the extended temperature part that is operational to 105C
Hmmm, looks like the price went up a little in the last few weeks… you now to buy 100 for that price (or the old price was an error). http://il.mouser.com/ProductDetail/Atmel/ATtiny85-20SU/?qs=sGAEpiMZZMtkfMPOFRTOlzm3F7l5sNgt
Thanks PPtk/Pyro!
I’ve been using WINAVR for a LONG time. It’s never given me a reason to change and works well outside of an Integrated Development Environment. Besides, I do a lot of AVR development work on a Compaq Armada 200 MHz WIN98 laptop… 0:)
I’d probably use the AVR Studio compiler or the WinAVR replacement on a newer machine.
IAR stuff costs money… I’m a cheap bastard.
25 pieces gets you below $0.65 at Digikey, and thats for the extended temp part.. 100 Pcs even lower..
Here's an even better price.. For one piece..
http://www.componentsdirect.com/atmel-attiny25-20ssn.html
That’s the TINY25. Unless I need the narrow package, I always use the TINY85.
I know a guy that got 10,000 TINY85’s for free… a company threw them out because they had been programmed with the wrong code! Too expensive to reprogram them?
I'll take some! 
FWIW, when you're dealing with the usual 17mm 'limit' on flashlight drivers the extra width of the 85's package can count against it. I'm using an 85 on a driver I'm trying to build, but only because the code is currently larger than anticipated. If it can be re-worked to fit on a 25 I'm defintely switching to the narrower package.
Big Code Space + Small Physical Size = ATTINY85 in QFN Package. At 4MM Square, it's smaller than the Narrow SOIC. They're not THAT hard to solder by hand, either..
I got burnt (figuratively) trying to solder some Attiny13A QFN chips as the leads had NO outside 'edges' or whatever they are called. The PICs used on your 3XML driver look like they'll be easier as some of the contact is actually visible even when the chip is flat on the board.
But still, good point to consider especially the space requirements of this driver. The downside is, again, that you'll need breakout points to program it on board.
On QFN's that have ZERO exposed pad, the trick is to tin/bump the pads on the actual PART first, then put some flux on the board, set the part in place, and heat each pad with a tinned iron. Once you've done it a time or two, it's easy as pie...
If you have the part lined up correctly on the pads, the joint will jump right from the part to the pad. It's really not at all difficult once you get the hang of it - you can solder all 8 joints in 16 seconds..
Yeah I had just bought a air solder/reflow station and was a bit over excited. I cooked the uC while I was trying to get the solder paste to reflow. Lesson learnt 
You cooked it? How hot were you running the air? 320C is perfect for SnPb, 360 for Lead-Free. Heat evenly using rotating motion at about 1.5 - 2.0" from the part.