This is a delayed giveaway, I didn’t get these done in time for 2000 posts. Now they are almost ready so the actual giveaway thread can start.
I’m giving away a few of my latest drivers. Who gets one is based on firmware suggestions and/or what ever reason I feel like. I’ll probably use a random generator for one or two. If you have been around and active for a while (not just entering GAWs) you can enter, but a simple “I’m in” won’t quite do it this time. I’d rather not build, flash, calibrate, test and post them to off someone who’ll just have them laying around in a drawer. Give away rules lower down in this post.
If there is any interest in the workings behind these drivers I can start a separate thread but I don’t think it will be needed, these drivers are incompatible with any other BLF driver/firmware that I know of, I think BLF driver/firmware development is going in a different direction than mine.
Also, I haven’t used these drivers extensively yet, they are pretty new. I don’t really know how they will hold up in the long run. I guess you could see this giveaway as more of a prototype/product test… ??
So, what am I giving away? A few of each of these two drivers:
FAT-3:
SLIM-4:
They have firmware controlled constant current output (no PWM) from 0.15A to 3A (Fat-3) or 4.5A (Slim-4). The difference is Fat-3 has a FET for full blast boost, the Slim-4 has a 1.5A current regulator instead. Both have 3 x 1A current regulators on the spring side. I use 10 bit PWM on 0.15A for really low and moonlight modes. These are v1.2, v2 is on the way where I’m aiming to get constant current range down to 0.06 amps before needing PWM. I don’t know how well those will work until I get them, if this giveaway goes on for long enough they might have arrived in time for testing.
The single most important thing to know about these drivers that make them different from most BLF used drivers are that my drivers use high side current regulators. The commonly used 7135 current regulators are low side regulators. Here is an attempt to explain the difference, the blue box symbolizes the regulators:
Low side:
The battery plus is connected to directly to LED. The LED- is connected to the 7135 regulators (and/or FET), which then regulates current to GND. In short, the battery feeds directly to the LED, regulation is done on the low side of the LED. This is what most BLF drivers do, it’s how 7135s operate.
High side:
The regulators Ive used for my drivers work differently. Battery plus is connected to the regulator which then regulates current to LED. The LED- is then connected directly to GND. In short, the regulator feeds to the LED, regulation is done on the high side of the LED. Do not wire spring bypass directly to LED+! Also, the “standard” N-channel FET used on most BLF drivers won’t work on high side so for the Fat-3 I’ve used a P-channel FET with a small gate mosfet.
So why these regulators then? Many adjustable current regulators use current sense resistors with really low values than can’t easily by changed. The regulators I’ve used require resistors from 1K and up. This enables me to use a 256 step digi-pot instead of a fixed resistor, giving me 256 possible current outputs from a single regulator. When it reaches max I turn on another regulator with fixed resistor and reset the digi-pot back to lowest output (max resistance). This means each additional regulator gives me another 256 possible current outputs. In order to simplify mode value entries in the firmware I’ve used the formula so each mode is entered as amps by 1000. For example, 1.8A would be entered as 1800. Because of tolerances in the digi-pots, resistors and regulators it won’t be 100% accurate. I could calibrate each driver but I really couldn’t be bothered, it’s accurate enough for me.
These drivers support E-switch, clicky (off-switch) and dual switch (E-switch and off-switch) configurations by default, no changes in hardware or firmware. Note that E-switches are connected to VIA holes on the driver, there is no E-switch mounted directly on the driver. These drivers have additional VIAs for flashing firmware, and also two additional inputs/outputs that can be used for another E-switch or controlling lighted switches or slave boards. I haven’t developed any features in firmware to use these things yet but hardware supports them. One of the VIAs is a PWM output. It has however been removed on coming v2 versions because I ran out of space (could be good to know if you plan on using it).
Give away rules:
If you are interested in trying out one of these drivers, enter this giveaway! I’m looking for inspiration for firmware functionality and features. I want to know what UIs, functions, features you like from your favorite firmware. What makes them your favorite firmware? Don’t just write “like Narsil” or similar, because I have now idea how Narsil or any other firmware work! (I haven’t used other firmware since Star 1.1 for ATtiny13A). I just want to know what specifically you like about them, or what your optimal UI would be like for any dedicated switch type. Do you like normal mode firmware? How many modes? How do you like selecting modes? Or do you prefer ramping? Perhaps you like to able to switch between both? What options you like and how you select them? Stuff like that, and for any switch configuration.
Note that these are 1S drivers. The regulators are not specified for more than 6V so I have not designed them for 2S or more. As they are high side regulators I expect them to be more sensitive than 7135s, but honestly I haven’t tested and don’t intend to. I’ll also be sending them pre-wired. I need to hook them up to run a full diagnostics test and calibration them, I sure don’t want to send out drivers that are not tested. 12 of the IOs are used so there are a lot of connections to test. I can put on a small spring if requested, only small Nanjg style springs or similar will fit (not always easy to find: Where to get the small springs found on Nanjg drivers?)
Three people are already receiving one of these drivers for various reasons: DavidEF, Schoki and ifratos. You don’t enter, you are receiving one of these of your choice in any case. However, your input on firmware is more than welcome!
So, post firmware preferences and/or desires to enter. Give away ends when I’ve built enough of them to start giving them away. Don’t forget to tell me which one of these two drivers you would like, Fat-3 or Slim-4?