Mod - GarryBunk's SecurityIng HD-016 (It's Finally Done!) - Pic Heavy

I haven’t gotten around to temperature monitoring in my headlight project yet, but my thoughts are that I obviously don’t want to exceed the MCU’s operating temperature as it’s the MCU’s internal temp sensor I will be using (ATtiny84V). Having it ramp down at 150c if the MCU is rated to 125c is useless, unless you are counting on the MCU being able to fully operate at 150c. Also worth considering is when the temp sensor reaches a certain temp, how hot is the rest of the stuff? Is the temp sensor directly in contact with the host or is it taking the temp of the air inside the host?

If the goal is to be able to touch the light without discomfort, then I’d just do some trial and error as it is probably lower than what any of the components are rated for. If the goal is to push this light to the limits of what the components can handle, then I guess you’d have to figure out the weakest link and check how hot that link is at a given reading from the sensor.

Thank Mike C. My guess is Garry will want a much, much lower step down than 125c or 150c (257f - 302f). Having something that hot, even if mounted to the handlebar, will pose a safety issue to anyone around that might want to casually touch the light.

There will be a little lag on the sensor reading, but not a lot. The light is very compact and copper will conduct the overall temp of the host to a spot close to the sensor. The sensor will have some thermal compound connecting it to the copper/body.

I agree, any temp Garry decides on will be much lower than even the weakest component can handle.


EDIT:

Tried to get more accurate readings on when Thermal Step Down kicks in and when it kicks off. It's tough because I'm using an IR meter and the driver is small. Best I can tell, thermal step down kicks in around 140F (maybe a few degrees higher). Step down kicks off (meaning light resumes normal output) around 120F. Now I'm starting to think the stock set up is what I recommend sticking with. The light itself will be a little hotter before the sensor reaches 140F. That's starting to get hot enough to be a safety concern. Enough to give someone a burn, but they should react fast enough to not get serious burn.

My biggest concern is a different safety issue. That is the light steps all the way down to Low Mode while the rider is in treacherous terrain. The higher the thermal kick down point, the less thermal kick downs will occur, but the burn risk then increases.

If the rider had a helmet light on, thermal kick down won't be as big a deal. Maybe slow down a little and then switch to Medium Mode after thermal step down kicks off.

I reprogrammed Low Mode to be more than 25mA, but the driver still steps down to 25mA when thermal step down kicks in.

I haven’t really been following what you can and can not do with this driver. What kind of control do you have over the temperature monitoring? When I get around to temp monitoring on my project I was thinking about a hidden temperature controlled mode. Instead of running on highest until too hot and stepping down to low I was thinking about running it on the highest it can run for a given temperature, lowering the output gradually as the temperature rises towards the threshold.

I have no idea how practical this will be until I try it out, but maybe something like this would suite a bike light better than going from high straight to low without warning, but it seems that this would be difficult on the driver you have as it appears to go to 25mA despite the low mode is above that.

^ Our options on this light are limited because we can not reprogram the unknown 14 pin MCU. The MCU is from the KD driver for the ________ (forgot model) bike light. So all I can do is tune the voltage divider that the thermistor is part of.

In your case, you what ever options you can imagine and program. I think many folks (Including me) will be interested in your work on that front.

I see. Yeah, your options are very limited in that case. As mentioned I haven’t been following to the full. I thought that as you where going to piggy-back a 13A that you might have had more options.

I’ll make a thread about my project when it reaches prototype testing stage. Right now I only have the driver board assembled. I have a host to test it in once I get the firmware ready for field testing, but the programming is taking it’s time. It’s a dual LED type like this project, but with both a mechanical and electronic switch.

For reference, the stock Yinding light has been measured with a case temp at 150 degrees at thermal stepdown. I can concur that my Yinding the other night was pretty darn hot when I ran it on high for about 5 minutes during a downhill descent. I was fine with the case being that hot (as far as potentially burning myself goes). I would likely also add an aluminum GoPro mount (seen in that thread linked above) to another aluminum GoPro handlebar mount (like these) and have it attached to my aluminum handlebar.

EDIT - Here is a link to the KD driver being partially used in this build. The light it is intended for has been referred to as the "KD2".

-Garry

^ OK. Unless I hear otherwise from you, we'll stick with the stock configuration on themal step down. I image the case will likely hit 150F since there will be a small time lag before the heat hits the thermistor.

So, all the ingredients are on hand and adjustments have been made. I now need to finish deciding on how mod the driver to accommodate the cable gland for the new cable. Once that is down, it's assembly and some follow-up testing. I redo the OP with the complete build once the light if finished.

Mike C wrote:I see.

Yeah, your options are very limited in that case. As mentioned I haven’t been following to the full. I thought that as you where going to piggy-back a 13A that you might have had more options.

Yeah we started this project with the Attiny13a, but it had limitations that prevented realizing all the functionality Garry wanted. Luckily, the KD2 came out with all the functionality Garry wanted. Garry was able to get KD to sell just the driver. That put us on the long road to merging the 2 drivers for this light. The OP is crazy out of date and I will update it as soon as I finish this build.

Look forward to your thread. You said you will use the Attiny25? I know it may be a while before you get to that point, but should I order some now so that I can hopefully help with some of the testing?

That actually rings a bell… quite sure I did read this some time back.

In my headlight project I’m using the ATtiny84. It’s 14 pin with the 8K of programming space. I’m using about 5K of that as it is, and have a few more features to put in before I build the prototype light.

For the 8 pin MCUs in other drivers I’m using the ATtiny85 (also 8K of space). It fits on a 13A footprint with a little pin bending. This firmware isn’t really releasable yet, it’s on hold because I’m prioritizing my 84 headlight firmware. I plan to upload a Q-lite compatible version of the 85 firmware to ToyKeeper’s firmware stash when I’m done. As it is now it only works with my own drivers as I use different pins for everything.

The light is finally completed. I have totally redone the OP to document the final build. All other mods that were done, but tossed have been removed to reduce the size of the OP.

Nice to see it finally done! Lot of nice work there, in particular the copper.

Were you able to have any control over what the light steps down to when thermal protection kicks in?

I see you did get beamshots uploaded. Very nice! I can't wait to try it out for myself!

I appreciate all your hard work on this ImA! It looks fantastic!

By the way, I picked up another one for you to mod just like this one, okay? Just kidding! (I wouldn't do that to you.)

Thanks,

-Garry

^ LOL. Good one. I took some "before" beam shots, but I'm trying to make sure I have the right ones. You take much better beam shots than me (by like 2000 million percent). Hoping you have some befores and take some afters. I have to say that I really love the tint of the emitters you provided. I'm going to order some. I thought I had that same tint, but mine are slightly different. That small difference is big though.

Mike C wrote:

. . .

Were you able to have any control over what the light steps down to when thermal protection kicks in?

In the end, I opted to keep the step down temperature at the stock 150 degrees Fahrenheit. The biggest reason was to reduce the likelihood of step down when Garry is riding because the step down is very drastic (goes down to .26A). Since the light will be handle bar mounted, it seems like a fairly low safety risk burn wise. If Garry puts the light on an aluminum mount and aluminum handle bar like he said, I think he will have no stepdowns. I didn't expect such a big lag (body reaches 166 at kick down), but I think it is a plus for this application. The aluminum mount will bring down the temp fast.

Yes, I will try to get some "after" beamshots in the same locations that I got my "before" shots. I'll post them up when I get them.

-Garry

Got in a short ride on the local rail-trail last night to test the light. This light rocks! Huge wide flood with decent throw (throwy head lamp really combines for a killer combo) and with my favorite 5B1 tint! In use this thing gets hot quick! While I was riding with it (mostly slow. perhaps 8 to 10mph) it did not kick in. This was with the simple stock plastic mount (need to upgrade to aluminum GoPro style soon).

Some pics (description above the photos):

Low (I think it's level #2 on the KD driver as I mistakenly entered program mode and am unsure where I set it back to):



Medium (level 7):



High (level 10):



Stepped back from the bike for a shot to show the full flood on high:



Excuse the photos as I was not carrying a tripod and I had my camera mounted on a cheap handlebar mount that had a lot of play in it. The camera also mounted on an angle due to being on my riser bars so I had to tilt the bike to make the photos appear level :) .

I was NOT using a helmet light (nor wearing a helmet), but while riding I did hold my Convoy M1 XM-L2 T6 4C on my head to simulate and it looked great! Provided all the throw I needed.

Comparison "backyard beamshots" coming in the near future.

-Garry


Hats of to you ImA4Wheelr. What an extraordinary amount of effort has gone into this light and it works not that I had any doubts.

Thanks for the feedback Garry and the compliment MRsDNF. I really like those trail beam shots. You must have had a late night making that happen. I have to give you credit for the light's rockability. It was your concept to combine the beams at all power levels, go 5B1 tint, AR lenses, improve the heat sinking, and to controll all that with a solid mountain-biker-safe UI. I'm honored you asked me to make it a reality.

MRsDNF, you always seem to notice the critical parts of a process/build. You are right that it was a lot of work. It also was close to not working. I just about gave up several times. Garry was good at keeping me in the game. Now that it's done, I'm grateful to him for that. I learned tons from this build and it forced me to grow in areas I tend to neglect. I really noticed my growth last night when putting the final touches on my Rook. I'm a better modder now. I also learned that custom builds are definitely not my cup of tea. I really admire the folks like you that undertake them. It takes a special skill set and attitude to be successful at it.

EDIT: How do you get the pictures scalable to the screen like that Garry?

EDIT2: Fixed cap in MRsDNF. Sorry about that.

About the pics, I use the advanced post editor and on the "appearance" tab at "dimensions" you put "100%" (or whatever size you desire) in the first box and clear the second box. That simple.

-Garry

Ok, here are my beamshots I promised. I was in a rush to beat a storm coming, and didn't notice the first shot was way out of focus (I did almost get some shots with lightning strikes in the background!) Also, the original beamshots had a wrong white balance setting and appear more blue than they should (should appear a crisp cool white). My modded beamshots are with the KD driver programmed at levels 2,7, & 10 (I think low is "2", but I never confirmed that after my accidental reprogramming). Keep in mind the stock light was only driven at +/- 1.4A per emitter and now it's modded to 2.4A per emitter. Original beamshots are only with both LEDs on (no sense comparing single throw / single flood shots).

Modded Beamshots, distance to the two trees is approx. 185 feet (I aimed at the tree to the left). Approx. 275 feet to the house off to the left of the tree.:

Low:

Med:

High:

Wooded "simulated bike trail":

Low:

Med:

High:

Mouseover's with original Un-modded Light (Mouse Out=Original, Mouse Over=Modded):

Yard:

Wooded:

-Garry

Really nice beam shots. Really dig the tint of those emitters. Really make the colors pop too. Thank you.

I think the beam shots belong in your bike light thread though because that is a great go to thread to see the beam shots from all your bike lights. Or, maybe make a copy the above post there.

Done. Yeah, the tint difference really does makes things "pop out" better. Even though the white balance was off, it still affects the appearance of everything not just the light output, so the detail you see with the wrong white balance is still the same detail you'd see if I had the white balance correct.

-Garry