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Thanks for the ideas. Please allow me to switch to "devil's advocate" mode and
take a critical look ...
As it happens, the present regulators are both low drop out and work fine with
2S Li-Po packs. The unit runs right down to below 6V, although my Fr-Sky
transmitter module also requires minimum 6V. The 3.3V regulator was especially
chosen too. It's one that doesn't like much more than 5V input, and give low
drop-out, low loss in return.
The LCD back light, of course, already runs off a switching, step-up supply,
and uses precious little power, thanks to the phosphorus at work.
The LDR idea is an interesting one, except there isn't really any spare place
to connector such a sensor -- certainly not if we want to read analogue values
by the CPU.
Also, with my current 2S Li-Ion cells (TrustFire 2Sx3.7V at 2400mAH), I get
days of run time, even with the backlight on a lot of the time. So, whilst it
would be a nice feature, I don't feel it's needed.
Certainly, when running from an 8S dry-cell pack, things are not so efficient.
I do not recommend this at all. Far too expensive in the mid to long run.
More comments always welcome.
Original comment by gru...@gmail.com
on 17 Jan 2011 at 9:29
Oh and, single cell reading -- perhaps even with a built in Li-Ion charger ...
again, there are no spare analogue ports. I suppose I could multiplex other ADC
ports "only in charge mode". But that's a poor solution.
In theory, though I'm yet to test it, the TrustFire "protected" cells (they
have a little round circuit board at the negative end of each cell) should be
safely chargeable with a simple, crude charger -- the likes of what could
already be plugged in the existing charge socket. I need to find more
information on this. But the sales literature does say, "protects from over
charging."
See this article concerning the cells I use:
http://www.rcmodelreviews.com/tendollarbattery.shtml
Original comment by gru...@gmail.com
on 17 Jan 2011 at 9:33
hi, they are the same cells I use :)
last times I charged them one by one with crocodile plugs, but I noticed they
keep well balanced. I also removed the diode on the charge plug so I can also
use the jack port on the side.
I'll keep you informed with new ideas.
Original comment by reis...@gmail.com
on 17 Jan 2011 at 9:36
On the other side of the coin, I am thinking of going further with the next
custom board design, by moving up to a more powerful chip, with at least
another 20 odd inputs. But that's a complete redesign from the ground up, as
well as major changes to the code base. So it won't be happening soon. For one
thing, I'm completely out of money to fund such a project, so that too would
have to be remedied, somehow.
P.S: The guy pictured at the ten-dollar-battery site is Bruce, not me. :p
Bryan.
Original comment by gru...@gmail.com
on 17 Jan 2011 at 9:37
what about a cortex m3? 32 bits and plenty of power.
I really like this radio and I think it can become the perfect one.
Original comment by reis...@gmail.com
on 17 Jan 2011 at 9:42
The V4 PCB design, being produced by a new contributor (Cam), is using the
100-pin ATmega2560 chip. I believe there will be free ADC ports available. So
the individual cell voltage measurement could possibly be added. I'll point Cam
to this issue's comment thread.
Original comment by gru...@gmail.com
on 21 Jun 2011 at 10:43
Voltage dividers to the spare ADC channels have been added to the V4 PCB.
Cam.
Original comment by th9...@gmail.com
on 21 Jun 2011 at 7:44
Plans are being discussed to design a built-in LiPo charger -- as a separate,
optional add-on board, probably replacing the transmitter module (all but
blank) PCB in the rear of the cabinet. Might make sense to stick the SD card
interface on there also. We shall see. Such a board will require the single
cell reading feature, so the V4 (or V5) PCB(s) will include whatever is needed
for that interface, later.
Original comment by gru...@gmail.com
on 28 Jun 2011 at 6:01
This one has been lost in the noise and no longer thought to be of priority.
We're letting it go.
Original comment by gru...@gmail.com
on 30 Dec 2011 at 2:30
Original issue reported on code.google.com by
reis...@gmail.com
on 17 Jan 2011 at 3:01