Uber simple HUD reminder thingy

[bogan]

Sorry for asking the annoying question. But I tried reading and now I am tired.

But, In once sentence. What does it do?

e.g. wire in input contacts, little thing flash in helmet when contacts close.

yup, thats the basics of it, also added special functions for audio, rpm, and a delay for the indicators (you don't need to know you just turned them on)

[imdying]

AAA is too big as I would need 2, maybe 3 of them. If I can get the sleep duty cycle up there enough with hardware interrupts I can probably stretch out the lifetime to hundreds of days. Which is getting into the region of doing away with the power switch on the receiver. Batteries are about 10 bucks to replace.

How about the 12v cells that are used in garage door remotes, the A23. Sure it's just a stack of cells, but maybe more convenient, especially to sort out a mount/holder for?

Size:

[bogan]

How about the 12v cells that are used in garage door remotes, the A23. Sure it's just a stack of cells, but maybe more convenient, especially to sort out a mount/holder for?

Size:

yeh was thinking it may be better to stack them that way anyway, however, I need 3.6V, anything over is just wasted, and 25mA, the later I've found to be pretty rare in button cells.

[imdying]

yeh was thinking it may be better to stack them that way anyway, however, I need 3.6V, anything over is just wasted, and 25mA, the later I've found to be pretty rare in button cells.

No worries, if anything else comes to mind I'll post it up.

[bogan]

Done some more testing tonight, found that the reg is whoring up the power, drawing 180uA through the ground pin, so will get rid of that somehow. I've got the rest of it sleeping at <2uA (but I'm unsure as to the accuracy of the multimeter, with some programming I think i can get it down to a 50uA or less average draw, giving a theoretical life of 562days for the batteries I got. However I did some more reading on zinc air and after they are unsealed their self discharge rate is pretty high and they only last a few weeks

So looking for better batteries, have to be 2.7V-3.8V (reg can fuck off if it's in range) capable of 25mA output, decent capacity (>500mAhr would be ideal), and as small as possible.

[jonbuoy]

Done some more testing tonight, found that the reg is whoring up the power, drawing 180uA through the ground pin, so will get rid of that somehow. I've got the rest of it sleeping at <2uA (but I'm unsure as to the accuracy of the multimeter, with some programming I think i can get it down to a 50uA or less average draw, giving a theoretical life of 562days for the batteries I got. However I did some more reading on zinc air and after they are unsealed their self discharge rate is pretty high and they only last a few weeks

So looking for better batteries, have to be 2.7V-3.8V (reg can fuck off if it's in range) capable of 25mA output, decent capacity (>500mAhr would be ideal), and as small as possible.

What about cannibalising a Nokia mobile phone battery, small Li Ion 3.6v 950mA.

[bogan]

What about cannibalising a Nokia mobile phone battery, small Li Ion 3.6v 950mA.

Bit on the big side, and then I'd have to sort out charging them etc, be alright for very low volume where you just just buy broken phones, but probably get a bit pricy for high volume. I'm thinking two vertical AAAs with a 15mm gap between for the circuit, gives me around 10mm helmet-face clearance on mine still, more if it's off to one side. You guys reckon that would be suitable?
Lithium ones should be good for a few years, or alkaline replacements could be used as well, anything 1.4V and higher, so no rechargeables.

[avgas]

Sorry for stating something that sounds a bit stupid, but why not make the battery pack external and run a power lead out.
Can always velcro some AA's (or any other batteries) to the back/bottom of a helmet.

[imdying]

I've got one of those waving cat things on my kitchen window shelf, it's solar powered... with such low current requirements, one of those any good?

[imdying]

I'm thinking two vertical AAAs with a 15mm gap between for the circuit, gives me around 10mm helmet-face clearance on mine still, more if it's off to one side. You guys reckon that would be suitable?

That would be fine, AAAs weigh bugger all and the power has to come from somewhere. That, and with the current draw you're talking about, they should go forever... and if they don't they're cheap and easy to find. No rechargables is fine too if you're going for such a cheap/common battery.

[bogan]

Sorry for stating something that sounds a bit stupid, but why not make the battery pack external and run a power lead out.
Can always velcro some AA's (or any other batteries) to the back/bottom of a helmet.

External adds complexity and wiring could get buggered, also doesn't look as nice.

I've got one of those waving cat things on my kitchen window shelf, it's solar powered... with such low current requirements, one of those any good?

See above, and with such a long expectancy from a AAAs, if it fits good in most helmets, and ok in others, they will be the way to go.

[ducatilover]

I have these really strange lights on my dash that for some reason flash as if to remind me I am using my indicators :P

[avgas]

External adds complexity and wiring could get buggered, also doesn't look as nice.

heh your another engineer aren't you.

Word of advise from one engineer to another. There is a point of over-engineering. We can't see it. But it exists.

The difference between perfection and error is one you can recover from, the other you never fix.

[bogan]

I have these really strange lights on my dash that for some reason flash as if to remind me I am using my indicators :P

shhhh au, don't tell them about the compeditor's products!

heh your another engineer aren't you.

Word of advise from one engineer to another. There is a point of over-engineering. We can't see it. But it exists.

The difference between perfection and error is one you can recover from, the other you never fix.

indeed, what gave it away

Both over, and under-engineering will lead to a poor quality product, better to just apply quality-engineering the whole way through

[Aristocat]

In the meantime, could we do something like this? Seems pretty simple; use an input (in this case radar audio) to trigger some really bright LEDs. No helmet, no wireless, no batteries. Can you do this?