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Discussion Starter #1
For any seriously useful bike headlight, a number of light output levels is highly desirable, if not essential. I would like to raise for discussion :-

(a) Is the almost universally employed method of sequentially switching between modes convenient or optimum?

(b) How many power levels are desirable? (Assuming a convenient way of switching between them)

(c) If we could choose, what is the best method (user interface) for switching between modes, or power levels?

My own views on (a) are shaped by owning multimode LED torches, and I absolutely can’t stand them!! You know the deal, one click to turn on, next click gives low power, next click a useless gimmick flashing mode, next click back to high power and so on. Drives me totally nuts. Even ignoring the flashing mode that I don’t want, but am still forced to cycle through, I find the method of sequentially cycling through “N” modes to be silly and completely unsatisfactory. This sequential method suits manufacturers because it is very cheap and easy to implement, especially with microprocessor based designs. Too bad it is a total pain in the arse to use ….

Here’s what I want. It would be nice to have around 8 power levels, and essential to have a method of simply and instantly switching from any power level, to any other power level. No led driver board that I know of comes even close to achieving this goal, so I’ll build my own. My suggested solution is simple.

For the purpose of illustration, I’ll assume that the light I’m building has a maximum output of 700 Lumens, which will be close to the truth. On the back of the light there will be three small toggle switches, arranged in a horizontal row.

The left hand switch, switches100 Lumens of light in or out.
The middle switch, switches 200 Lumens of light in or out.
The right hand switch, switches 400 Lumens of light in or out.

Being a binary sequence, that gives 8 power settings, from zero up to 700 Lumens, in steps of 100 Lumen. OK, that’s a nice start, but what really rocks is the ease with which you can instantly switch from any given power setting, to any other power setting. Here are some examples of switching functions that would commonly be required, illustrating the power and convenience of this simple arrangement. Note that here in Oz, switches are turned ON by pulling the toggle downwards.

(a) From ANY power setting, you wish to instantly go to full power. Easy, push all three toggles down, in a single action.

(b) From any power setting, you wish to instantly turn the lights off completely. Easy, pull all toggles up.

(c) You decide that 700 Lumens is ideal for “high beam”, and 300 Lumens good for low beam when you see an oncoming bike or vehicle. Easy, with all switches down for high beam, pull the RH switch up for low beam, then down again to resume high beam.

(d) You are riding at full power, and decide to cut the power back just slightly to conserve battery. Easy, flick up the LH switch to remove 100Lumen, or the middle switch to remove 200 Lumen, or both to remove 300Lumen, or RH switch to remove 400 Lumen. Of course,should a corner or tricky section come unexpectedly, you can be back to full power in a flash (if you'll pardon the pun) by pushing all toggles down.

I think you get the idea. By pulling toggle(s) up or down, you can simply and almost instantly go from anything to anything, which is exactly what I want, and will tolerate no less.

This is very easy to implement in the driver hardware – I can talk about how to do that if anyone is interested.

Toggle switches would not be suitable for an underwater light but, provided the toggle is horizontal or slightly downwards facing, I have never had a problem with waterproofing, though I do try to avoid riding for hours in heavy rain ….

Does this idea make sense to anyone else, and has anyone else tried it?
 

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Just a thought... can the eye easily tell the difference between all 8 levels of power?

Obviously 100 has a power save over 200 but it is enough to make the extra build complexity etc worth while?

On the lights I've got with TaskLED drivers, I don't bother with the 5 diming mode - 2 is enough.
 

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I agree 2 levels are perfect as I use Taskled drivers for all my lights.
One thing I think we are all overlooking is the size of batteries has fallen dramatically and the capacity has increased enormously really negating the need for dimming at all!
 

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Yes I am in agreement too , Have tried the multi mode on taskled drivers and much prefer the duo mode Hi / Low even better with a remote switch next to the shifter .

Light housings are by design as small as possible and having 3 toggle switches would be a no goer for me nearest I would get to that would be a 3 position switch Off / Hi / Low
 

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Discussion Starter #5
Harpoon said:
Just a thought... can the eye easily tell the difference between all 8 levels of power?

Obviously 100 has a power save over 200 but it is enough to make the extra build complexity etc worth while?

Agreed that 8 power levels is more than enough, but as I see it, why not have them if your setup can conveniently accommodate 3 toggle switches?

Another option would be 2 toggle switches, giving off-low-med-high. Even if your light is only 20mm in diameter, that is big enough to fit 2 miniature toggle switches on the rear endplate. I have such a switch in my hand - body is 8x5mm, and could be mounted at 8.5mm centers, closer spacing being limited by the 8mm diameter mounting nut.

I agree with Troutie that even a single 3-position toggle (off-low-high) is a useful and far superior option to the sequential method.


On the lights I've got with TaskLED drivers, I don't bother with the 5 diming mode - 2 is enough
If you are forced to sequentially cycle, then I agree that 2 modes is more than enough !!

Best I shut up for a while and actually build something.
 

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One of the first lights I made used a pot so had infinite variability. My feeling was I always had it a little brighter than I needed, so noticeable steps is useful.
The five level taskled UI is probably as much as anyone needs, and more than enough for some. Again, depends on where you ride. My rides tend to be lots of steep up and down and a little flat so three levels is fine. But in the wet those three levels need to shift up.
 

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I use Tasled too and only ever use the multi (5) mode when I use the light for night walks, on the bike though high & low is enough.

I agree with you on the flash mode when it comes to high power LEDs, great in the past to help you stand out when LEDs were dim feeble little things.
 

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I like lots of levels personaly. So with the taskled drivers I use the 5 levels the ui with one button is simple just click it to get more light hold it for less. Want some more light click again. If I reprogram the driver I keep this UI but with potentialy more levels. Of course what I realy like to use on the bike (as opposed to running) is my custom setup with the speed controlling the light level via my home made bike computer.

I don't think I would get on with your 3 switches idea, far to complicated. I just need more light or less having to know what level I am at at the moment just would not work and finding the switches without looking may be problematic and when you want more light is not the time you want to look away from the trail.
 

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Discussion Starter #9
ifor said:
I like lots of levels personaly. So with the taskled drivers I use the 5 levels the ui with one button is simple just click it to get more light hold it for less. Want some more light click again. If I reprogram the driver I keep this UI but with potentialy more levels. Of course what I realy like to use on the bike (as opposed to running) is my custom setup with the speed controlling the light level via my home made bike computer.

I don't think I would get on with your 3 switches idea, far to complicated. I just need more light or less having to know what level I am at at the moment just would not work and finding the switches without looking may be problematic and when you want more light is not the time you want to look away from the trail.
Hi, and thanks for the feedback.

You make some good points. I agree that with my 3-switch scheme the user needs to keep track of what the current switch setting is in order to easily increase or decrease light output from the current level. If incrementing the light up or down in small steps is your main priority, then the Taskled interface you describe may be better, and would work sort-of OK, though still fiddly.

However, the UI you describe would be unusable for rapidly and easily switching between setting #2 and setting #5, for example, as I would frequently require for city riding.

The reality is that both schemes are compromised by the reality of the available mechanical interface. In the case of Taskled, they have done the best they can within the limitations of a single pushbutton switch. In my case, I have done the best I could think of using off-the-shelf toggle switches.

Both solutions are basically crap, and you would find neither in the cockpit controls of an aircraft, for example.

Lets open out minds for a minute, and think about how the interface problem would be optimally solved if we could have whatever we wanted. In that case, an excellent solution would be a 5-position (doesn't need to be exactly 5) slider switch, or slider potentiometer, on the top of the light. Incrementing up or down would be effortless, with the advantage of seeing at a glance where the current power output is within the available range. Going from "anywhere to anywhere" is also fast and effortless, whether it is a quick panic adjustment to full output, or rapidly moving to "low beam" setting for an oncoming vehicle. Unfortunately a high-quality, waterproof slider mechanism of this type is not available, nor likey to be, but I think it is useful to let the mind wander free and consider what funtionality we want, as opposed to what we are forced to accept.

In terms of a "microprocessor style" push-button interface, it is clear that a single switch doesn't cut the mustard. However, several push-button switches, each with a dedicated function, probably could. For example, on button to adjust the level up and down, another to instantly dim to a previously set "low" beam setting and then return to the previous setting, and another to intantly go to full power and then back to the previous setting.

Another solution would be a small rotary pot to set dimmimg level, plus a 3-position toggle switch, with functions:
Down = "low-beam"
Middle = "intensity as set by pot"
Up = "full power"
I'm throwing thoughts around as I write, but personally this option appeals to me the most. Apparently this solution does everything either of us want? Thanks Ifor, you forced me to think a bit more, and now I'll probably do it this way, at least until you force me to think again ....

Colin
 

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Another solution would be a small rotary pot to set dimmimg level, plus a 3-position toggle switch, with functions:
Down = "low-beam"
Middle = "intensity as set by pot"
Up = "full power"
I'm throwing thoughts around as I write, but personally this option appeals to me the most. Apparently this solution does everything either of us want? Thanks Ifor, you forced me to think a bit more, and now I'll probably do it this way, at least until you force me to think again ....
Would it not be easier to just turn the pot?
 

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Three settings by switch. low, mid high. Say 200, 500 800mA
Pot gives fine control, so will range the low from 50 to 350mA, etc
 

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Discussion Starter #12
yetibetty said:
Would it not be easier to just turn the pot?
No, for 3 reasons.

(a) Turning a pot is NOT a quick or convenient means of switching from one intensity to another, especially if the intensities in question are widely spaced as will probably be the case when switching to "low beam" and then back to somewhere near full power. Imagine if you bought a car that used a rotary pot to switch headlights in this way!!!! No one would in their wildest dreams consider that satisfactory in a car - enough said.

(b) A mechanical pot would wear out and get "noisy" if frequently spun between extremes for the purpose of high/low beam switching.

(c) The optimum intensity for "low beam" is a fixed value that the user would determine and set, and it would not usually correspond to the lowest intensity setting on the pot. So, quite apart from the slowness and general undesirablity of spinning the pot back and forth, you also don't want to be frigging around judging where to spin the pot down to when you quickly want to switch to low beam. Again, think "real world" and what would be considered satisfactory for a car.

I do admit though that everyone's needs are different. If you only ever ride offroad then maybe a rotary pot is all you need. However, the addition of a 3-position toggle switch costs you essentially nothing, and gives you much more flexiblity, namely the ability to INSTANTLY switch to full intensity, or a predetermined "low beam" setting.
 

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znomit said:
Three settings by switch. low, mid high. Say 200, 500 800mA
Pot gives fine control, so will range the low from 50 to 350mA, etc
That's an interesting idea....hadn't thought of that one before.

JZ
 

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I'm not sure you need to worry about a pot wearing out, at least not before the next big advance in LEDs when you may rebuild or scrap the thing anyway. I have used pots and the only drawback is trimming it down on the low side, and actually turning the thing on the trail, but the high side easy to get to. A rotary encoder (EDIT - oops, this was the wrong term - I was thinking of a rotary switch with several positions, can't recall the correct name right now though) would work as well, though try to find one that is sealed to any degree cheap, good luck.

EDIT - this is what I was thinking of, but I think you already mentioned them -

This is only 3-pos though:
http://www.goldmine-elec-products.com/prodinfo.asp?number=G17068


The driver I use has 4 basic modes, 2 flashing modes (going to be 1 next time I take it apart) and will step down when the LEDs get too hot or the battery sinks too low. The modes have obvious advantages, but the main disadvantage is that to go lower I need to cycle though off. Thought about setting it up so that with my on-off-on momentary - normally off switch, I could hit it up to go brighter and down to dim, while keeping the modes in tact. This seems like the best of both worlds since it is just a couple bumps to get to whatever level I need and there is still just one switch used - less stuff to break.
 

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Discussion Starter #16
Hi all,

I think there is more to be said on user interfaces, but decided to resurrect this thread rather than pollute Deesta's thread asking for comments on his light, which was not intended to debate the merits of UIs.

Re the taskled UI
It takes around a second to go from <10% to 100%, not much longer to drop back down.
Yep, that's fiddly by my standards. A good interface will whip the pants off that... And you need to count clicks to get to a specific power level, and then count clicks again to return to the same level, assuming of course that you even know what power level you are on, as you have no way of knowing.

Its a very nice interface.
There is a lot of thought gone into it, and it is probably the best that can be done with a single pushbutton switch. So much power and functionality built into these drivers, and all that functional power being bottlenecked by a single primitive pushbutton switch. It's like trying to piss through a hyperdermic needle - sure, you can do it, but I would go mad if I had to do it too often, and there are faster and better ways ...

If you use a remote switch its easier than changing gears.
That would certainly improve matters, in fact I'll revise my score to 75% for a remote switch implementation


65%???.....Arghhh totally disagree on this point, i have configured mine to
click "light goes on low" (50ma)
click "light goes off"
or,.....
click and hold "light goes to full"(1A)
click "light goes off"
surely it couldn`t get easier than that!!
I find one push buttion switch and duo mode far easier to cope with, rather than different switch positions to change light levels.
Exactly!!! You have had to 'configure" yours just to make it useable for some of the functions you particularly want, and the result is a very dumb and limited light indeed, that can do almost nothing else!!! "Duomode" is essentially an admission of failure, that the 'general" interface doesn't do most things very conveniently, so you have the option of greatly reducing what it can do, so that at least the few things that it now does, it does well. Whoa!!! Impressed, I am not.


With regard to driver I have my taskled set to touch button high, touch button low , Takes about a quater of a seond, same as a car and the best bit is hold for 2 seconds to turn off.
So if I understand you correctly, you have had to emasculate the underlying capability of 5 power levels down to effectively just two, so that the thing is useable.


The first light I ever made and still have (as it was the first) uses 2 toggle swithes, one for on/off the other for high/low and it is simply to easy to accidentally knock the switch and be plunged into complete darkness.
The 2 second hold to turn off is great as you can't switch off by accident.
Fair point, and accordingly I'll edit my previous claim that a good light needs a dedicated on-off switch.



I also find the taskled ui fine for bike light use. I do like the high/low beam thing. However, I use the multi-mode setting, the brightness changes rapidly. It's tap-tap for brighter, push-hold for dimmer.
Another perfect illustration of what I'm saying. In your case, you particularly like the multi brightness settings, but have had to forego a convenient high/low capability.

It is very clear to me, both from common sense and from the examples you guys have given me, that the taskled UI with single button control, can be set up to do a small number of things well, or a large number of things in a fiddly, inconvenient way.

This is a clear case of "liking what we are able to have", rather than "having what we would ideally like". Human nature.

I don't have a "compulsive dislike" (Troutie) of the Taskled interface. I think it is brilliantly good for what can be achieved with a single pushbutton. I judge it as I judge anything else. As with Deesta's light, I make a list of capabilities that a good general-purpose interface should have, assign a score to how well it achieves each capability, and average the scores. And that is exactly what I'll do in my next posting. Perhaps my 65% score was too harsh.

And don't take me too seriously. I enjoy to stir things up a bit:)
 

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More switches/buttons??? I think it depends on were the light is mounted and what the rider is comfortable with. I'm a light user not a builder(yet:) ) I like helmet mounted lights. I want 2 or 3 levels of light so I know run times for each. 1 button that controls all functions is easy to use (for me) and there is no risk of bumping another button/switch when bouncing down a trail one handed and maybe turn the light off completely.

Low beam for trail side stops, medium for when commuting through suburbia and high for every where else. Some of my riding mates have 5 levels and flash modes etc.....it just gets confusing in the the end they are forever adjusting it or they end up just leaving it on high as its not worth the hassle of fine tuning. If a car is approaching I just turn my head slightly to aim the light to the side until the car passes. Much safer than taking one hand off the bar, reaching up to my helmet to change to low beam then back to high again when the car passes.

Helmet mount, 1 button for high/med/low on/off, simple easy to do when riding along one handed trying to adjust the light. For a bar mount you could probably have more switches/buttons to control the light if that's your thing. Just because something can be complicated does not always mean it should be.
 

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Discussion Starter #18 (Edited)
My aim here is to try to identify the key capabilities that a good bike light user interface should have, then to score the Taskled style interface on each capability.

The scores will have little meaning unless compared against an alternative style of interface so, for want of something better, I'll also attempt to assign scores to the analog style interface that I use. This interface uses a rotary pot on the rear panel for stepless intensity control, with a toggle switch mounted on top of the light, to switch between the intensity set on the pot, and a fixed 'low beam" intensity. On-off is by a dedicated toggle mounted under the pot in such that it is almost impossible to accidentally switch the light on or off. I do NOT claim that this is an optimum way of doing things either, though I would claim it is better than the Taskled UI.


Elegance/compactness/simplicity/LowCost
Here is where the single pushbutton switch approach really shines, as it makes it easy to design the housing to be elegant, aesthetic, compact, simple, and a single switch is low cost and (relatively) easy to waterproof. Therfore, Taskled get 95%. My 2 toggle and one pot look somewhat awkward by comparison, though not too bad, so I'll score CD at only 75% here.

Number of power settings
I reckon you need at last 5 discrete settings, or stepless, and more than 5 settings is probably a waste of time. Taskled has 5 settings, I believe, for a score of 95%. As this particular score is awarded for the number of power settings, then presumably a stepless pot scores 100% here by definition.

Ease of changing power setting
This is a bit tricky to score for the Taskled, because it depends how it is configured. I'll assume that the the Taskled is set up so that a single press can increase or decrease the power by one step. Depending on whether you are increasing or decreasing power, and by how many steps, this operation could be performed extremely quickly, or relatively quickly. On average though, it is bound to be a bit slower and more fiddly than tweaking a rotary control, but not a lot in it. I'll assign Taskled 80%, rotary pot 90%.

Means of knowing current intensity setting
As far as I know, with the Taskled approach there is no easy way of knowing what the current power setting is, and I know perfectly well that it cannot be judged reliably by looking at the apparent intensity, because the eye iris quickly compensates. If battery life was unlimited there would be no need for intensity control anyway, as we would just use the highest setting always. The reality therefore, is that at any time, we strike a compromise between intensity setting and current drain, and for this reason it is very useful to know and keep track of what intensity setting is in use. For example, in my case I know that when the pot is at midscale, I have about 3.5 hours of use at 900 Lumens, so if my ride will be for about 3 hours then it's easy to keep the pot averaging around midscale. But here's the crunch. it would be a useless piece of junk if the control knob was perfectly round with no pointer and with no way of knowing where it was set, just the capability of turning it either way to increase or decrease intensity. However, in effect, that's what the Taskled system gives you - you can relatively easily increment or decrement the setting, but if you want to change the intensity frequently and/or rapidly over a wide range, then you will have to put considerable effort into counting clicks and generally keeping track of what the current setting is. And if you are not sure, then the only way to find out is to count clicks to an extreme, and then carefully count clicks back again .... For this reason alone I could not live with taskled. By comparison, the rotary pot knob gives both tactile and visual feedback at all times as to where the intensity is set. Tactile because I can feel the sharp raised par of the knob pointer, and visual because I can see it. So to the scores, Taskled can only manage 40% here, while the rotary pot gets 90%.

High-Low-High Beam switching
We are talking highish powered lights here, well capable of dazzling oncoming traffic on full power, which is both antisocial and potentially dangerous. Unless you exclusively ride in wilderness areas, away from other riders and traffic, then you must either refrain from using the higher power settings, or have some means of rapidly and easily switching from the current power setting, to a "low beam" setting, and then back to the original higher setting. This is a legal requirement for cars for good reason. My interface has a dedicated toggle switch for this purpose, mounted on top of the light, away from the other controls on the rear panel. Operation is rapid and simple, and a score of 95% is appropriate. The Taskled can be set up in "duomode" to do this, but then you lose the ability to easily access the other power settings. Under the third point, "ease of changing power settings", I assumed the Taskled was not set up in duomode, but instead set up for relatively easy control over the full range of power settings, and on this basis I assigned a favourable (80%) score for that task. To be fair and consistent, I must assume the Taskled is still set up that way, in which case it fails dismally for the task of High-Low-High switching. I think a score of 40% is generous - just imagine being on the second highest setting, then quickly clickety-clicking the damn thing down to a low power when you see an oncoming vehicle, then carefully counting the clicks to get back to where you were .... You have gotta be joking - try selling a car as primitive as that.

Over temperature protection
Although not strictly a part of the interface, I mention this because I think it essential for a top class driver. The Taskled has it, and so do I, so I'll score us both at 95%. However, I won't include in the scores, as the discusion was really about the user interface.

Averaging the scores gives 70% for Taskled, and 90% for my analog style interface. There was no "cooking the books" here - I honestly had no idea just how the numbers would look until I finished writing.

My earlier "guestimate" of 65% for the Taskled UI wasn't bad, but as a result of the above it seems like Iwas a bit harsh, and 70% would be closer.

However, on my best attempt to do a fair analysis, that's still a fair bit inferior to the 90% I come up with for a pot+switch style interface.

I'm not saying that the Taskled UI is BAD as such, just that it is possible to do much better.

OK you "Taskled UI Rocks" guys - what am I missing?
 

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Feathers ruffled.....no chance. In the end it comes down to what each user wants/needs/prefers. There is no right or wrong.

Have you got some pics of your light that shows all the switches etc you could post up so we can see it in more detail?
 

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Discussion Starter #20
I think it depends on were the light is mounted and what the rider is comfortable with. I'm a light user not a builder(yet ) I like helmet mounted lights.
Good point. My discussion refers only to bar mounted lights.


Some of my riding mates have 5 levels and flash modes etc.....it just gets confusing in the the end they are forever adjusting it or they end up just leaving it on high as its not worth the hassle of fine tuning.
I agree totally, and that is exactly the type of mickey-mouse frigging around that I am talking about, where there is only one control switch and features are accessed sequentially. You like simple and easy to use? So do I.

I'll see if I can post a pic of my setup, though it is very simple to describe. A recanagular shaped light with a rotary pot and on-off switch on the rear panel, and a high-low switch on the top. To be more precise, the "high-low" switch switches between a fixed low power (360 Lumen) setting, and the intensity set by the rotary pot.
 
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