The Hexbright was a Kickstarter project from a few years ago, to create an open source, rechargeable LED light. [Nick] quite likes them, and has learned a thing or two about keeping them operational.
The torches have a few key issues which [Nick] lists for us, before outlining the necessary repairs. These problems highlight certain design flaws, something one might expect for a hardware product from a new startup. Components inside are easily damaged if the device is dropped, and there is no reverse polarity protection on the battery.
It’s always disappointing to see a product in the marketplace fail to take into account such rudimentary things, but in the meantime, repair is always possible. The guide highlights the basic parts and tools required, which is important, but also goes the extra mile and gives important hints and tips on how to effectively execute the repair in a quick and easy fashion.
Overall, it may not be a hack, but what [Nick] has done both educated on us the mistakes made by a crowdfunded hardware startup and also taught us how to write a useful and thorough repair guide. It’s not just about the parts that need to be replaced, it’s about the best method to replace them. The details and the order of operations always helps – anyone that’s ever attempted a serious automotive repair knows this, for example.
We see a lot of great repair hacks here – like this excellent use of a 3D printer to reproduce belts for old hardware.
I guess “man fixes flashlight” was too straight forward
regardless, merry Christmas, y’all!
Man fixes flashlight, discovers Nirvana
A torchlight with no reverse voltage protection but with Atmega16 and accelerometer….
What the heck?
Hexbright users were expected to be smart enough to put the battery in the right way. The big red piece of plastic with an embossed “+” and black piece of plastic with an embossed “-” isn’t enough for some people, I guess.
It’s a cool flashlight, with a really good weight and feel to it, a nice very white LED (instead of that bluish tinge so many had before then), and a decent beam pattern. I’ve never reprogrammed mine, which was largely the reason I bought it. It may have changed since last time I looked, but back when I did, there was a version of firmware published, but not what was actually in the light, nor were the schematics available.
Doesn’t sound particularly open-source to me. Want an open-source LED flashlight? Well, do you have a battery, resistor, and an LED?
What would you program into this thing? Flash patterns?
Different intensities, flash patterns (lightning effect for halloween, works great with the main body off so light isn’t focused), hook up some external elements to the exposed IO ports for buzzer / vibration motor, vary light intensity based on angle to ground, etc.
I mean don’t get me wrong, it’s largely an exercise in what else you can make the LED on an Arduino board do besides blink – which is pretty limited, and is eve more limited in scope when deciding what, if any, of that is useful on a flashlight.
And yet, I’d love to see a HexBright 2 – or even just mod a BLFGT (can probably transplant an existing HexBright board to the side of the battery carrier for those) – because even if you just end up with off / low / med / high modes, they’re your perfect amount of low/med/high, and not whatever the manufacturer decided was good to go.
I don’t think the official final schematic was ever released, though the latest versions that were available were pretty close. The PCB design files certainly weren’t, not even the gerber files. The firmware that they came shipped with (if I recall correctly, it was just off / medium / high, and blink-when-holding-button-down?) was posted on github (should still be there?), but there’s much better firmware available with a range of functionality. The basic body and core design was also posted as CAD files. I’m not sure if the lens was.
As much as I would love to see the source files for it all – just to fulfill having them – I think the main aspect of programming it was readily available.
LOL… yeah because everyone is perfect… LOL…. no reverse polarity protection was a special level of fail….. one diode was all it would have taken. Sad… actually.
I’m sure it would have been thought of, my immediate reaction is “so you want to lose the forward voltage of the diode?”.
I actually came here to see if anyone had rejigged the micro USB into a USB C?
I reprogrammed mine to add a random strobe mode, plus changing the brightness depending on how I rotated the flashlight. I never did find a legitimate use for the reprogramming but it’s a good flashlight nonetheless.
I was one of the people that worked on development of the HexBright. My friend and I got on board with the project when the original electronics guy bailed. At that point it was already running late, the budget was getting close to crossing over to the wrong side of the break-even line, the circuit design was a little bit of a mess, and nobody had even started thinking about software. My friend did most of the work fixing up the electronics, and I did everything software. I wrote the firmware, made sure the arduino bootloader worked on it, and even figured out how to set things up so the factory in China could program lots of them fairly quickly. We did our best to save the kickstarter, but at that point any big redesigns were out of the question.
Nick is absolutely right about all of the problems. We actually discovered the crystal breaking problem on the very last pre-production prototype. I still have a really beat-up case laying around from when we were testing just how hard of a drop it takes to break different brands of crystal. (Spoiler: Every brand with that footprint seemed about the same, for us it always took more than a six foot drop onto concrete, and impact forces normal to the board plane seem to be worse than tangential.)
Still, fun to see it pop up on here after all these years. :)
Nice, thanks for the confirmation! I am the person who wrote the blog article. Some questions:
Was the oscillator you used MEMS based ( I was reading this marketing on how MEMS based oscillators are more mechanical shock and vibration resistant http://ww1.microchip.com/downloads/en/AppNotes/00002340A.pdf )?
Why no reverse polarity protection? I would gather that a simple diode could have been added for protection.
Also lastly, what happened to the production of these fine lights? Did the demand drop?
If you’re working with stable power (mains, rectified), sure you can use a diode. But ideally you want a PNP transistor over – with gate hooked to positive. Leakage and waste heat is cut to a minimum. And in battery operation, saving every uW matters.
If I use mains based power, yeah, I use the diode on -. It works, and doesnt usually have too much losses.
thanks for you work … still using the original kickstart light , after all those years … with the original battery … don h 03/17/21
One of the best flashlights I have owned actually. I bought two and later bought the upgraded lenses and Cree LEDs for the Hexbrights. The upgrade parts really fixed and changed the output of the flashlight. Still using them to this date, keep one in my car and the other in my backpack.
If i had one of these flashlights, i would put in the 8MHz internal oscillator bootloader (Like the Lilypad) 8 MHz is plenty enough and the accuracy of xtal isn’t needed in a flashlight anyway. Problem solved (with the xtal at least)
Yup, Andrew is 100% correct. He and another EE came in and helped me straighten out the electronics. We made improvements along the way and although I was tempted to do a complete refresh, LED flashlights are a “me too” industry. There are just too many companies. Still, I was happy to do it, learned a lot along the way, and very glad there are people out there who still like the overall use and feel.
Christian, I’m still using my hexbeight to this day and it’s one of the best Kickstarter projects I’ve backed… so from me … thank you! Garry
A little late, but I was going back through some other HaD comments, and saw this. Christian, would you be willing to post the latest schematics, CAD files, firmware and such somewhere, or perhaps provide them privately to those of us who’ve bought HexLights?
I have two, one of the original “Gen 1” models, that I replaced the LED and lens on, and a “Gen 2” model that came with them. These are some of my favorite lights I own, and I have a LOT of flashlights. The weight and feel is darn near perfect, the burn time is good, and the LED color is great. If I had one criticism, it would be a very minor one, and that’s that I >personally< prefer a slightly narrow beam angle. But that's me, and I don't know what most others prefer. I use mine when walking the dogs, and I like a slightly tighter beam to see more of the trail ahead, and less of the trees beside me. That being said, the HexBright had one of the first lens designs of that type, did it not?
Can you point me in the right direction of the battery tabs? Mine broke off on the PCB, and I’m having a bit of a hard time finding them!
Still use the hexbright every day… Had two but one died due to polarity issue.
I have 3 non-functional Hexbrights, one seems to be charging, and the LED goes solid green, but it only turns on once in a while, the next shows a red LED on the cap if you press the button while it’s plugged in, and the LED on the USB charger turns on, but it never flashes green or goes solid green, the last does nothing at all, and I chose to open it up and see if I could analyze what was going on. Unfortunately, although my electronics expertise would probably be adequate to the task, my shakes have gotten so bad that it is impossible for me to work on these ultra small SMDs.
I there anyone who would be willing to have a look at these and see if they can repair them?
I have bought several other lights that claim to perform as well, but have yet to find one that actually lives up to the claim.
I could take a look. I’m one of the people who worked on the HexBright’s development (see my comment above). Send me an email! See my address here: https://i.imgur.com/seUiLHa.png
Would like to contact you for possible repair. Link does not seem to work
I would love to get a repair done to a Hexbright. reverse polarity issue.
I could also take a look. I would recommend that you try and charge the batteries via removal and usage of an external 18650 charger first though. What voltage are they reading currently?