it's possible to power suply 9v to arduinobt? connecting in the pin 9v and gnd ?or it will kill it? cuz i have 3v as power but it ends quickly...thanks
According to this page:
the max is 5.5V.
I run mine on 3 AAs.
How long do your batteries last? What is your application?
You may be able to get more by lowering the power of the BT radio.
Mike
hi, i'm running on 2 AA and i have a program that is always receiving data from processing and displays it in a 16x2 lcd, how do i lower the power of the BT radio ? thanks
You can send a command to th BT module: SET BT POWER - it is in the user manual for iWrap, available from the bluegiga website, though you may need to register first.
You will need to put the module into cammand mode first.
The wt-11 spec sheet shows that max current when transmitting / receiving is 170mA.
How long do your batteries last? How long do you need them to last?
Mike
I'm suprised nobody has mentioned this on this thread, but a 9V battery will not last longer than a few AAA or AA batteries while powering a device. Higher voltage does not mean longer life.
You're right, of course. I depends on the size of the battery.
I don't know if there is enough room for a couple of D cells in the project.
You're right, of course. [It] depends on the size of the battery.
I believe the suggestion was related to capacity which isn't necessarily correlated to physical battery size.
Using 4 x AA or 4 x AAA (assuming 6V maximum is okay) will probably give you better results than a 9V battery.
You may find these Arduino battery life results helpful.
--Phil.
Using 4 x AA or 4 x AAA (assuming 6V maximum is okay)
The max is 5.5V. Its a shame as using 4 1.5V batteries would be convenient.
Mike
Why not use both serial AA's (to up the voltage) and parallel AA's (to increase the current available/draw time at the same current)?
If you hook up the batteries serial, they increase the voltage, but the amperage remains the same. If you hook them up parallel, you can get more amps, or increase the Ah rating.
For example, 3 AA's in series will give you 4.5V, but remain at ~ 2.8Ah hooking another 3 AA's (wired serial) in parallel to this combination would remain at 4.5V, but increase to ~5.6Ah, doubling run time.
That is, within each series, the negative is connected to the next battery's positive. Between the series, the negatives are connected together and the positives are connected together.
Edit: here's a link that shows both serial, parallel, and combined techniques: http://www.batteryuniversity.com/partone-24.htm
!c
The max is 5.5V. Its a shame as using 4 1.5V batteries would be convenient.
Nickel-Cadmium AA and AAA have a rating of only 1.2V/battery, or 4.8V for four cells. The rechargeable nature might be nice. NiMH cells are in the same range, but about 1.4V unloaded.
You might also try a simple boost converter (like LadyAda's MintyBoost) to generate the 5V from a lower voltage. An equivalent buck converter could be built for stepping down the voltage, but the boost converter is simpler.