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1  Using Arduino / General Electronics / Re: looking for a small alternative to AAA batteries on: October 28, 2011, 03:02:46 pm
not sure about how much current, but I have a 5v regulator going to the chip and to a 3.3v regulator where I have various accelerometers and other sensors...

Your image didn't get through, I don't think. And I didn't get anything useful from searching battery_hand or hand_battery...

And thanks for the website referral! They are cheap. but they don't seem to sell LiPos :-(

Was it the LiPo you said was  around 1" x 1.25"?

Thanks so much, f
2  Using Arduino / General Electronics / Re: looking for a small alternative to AAA batteries on: October 28, 2011, 02:24:41 pm
Very cool! Thanks Crossroads! How long do those usually last for? And do they recharge? They're kind of expensive...

Also, its 4 inches long :-----------<
3  Using Arduino / General Electronics / looking for a small alternative to AAA batteries on: October 28, 2011, 02:09:05 pm
I need to make a really small-sized board and was wondering if anyone has ideas about an alternative for using 4 AA or AAA batteries (to get 5V to my arduino chip) in a battery holder like this:

http://www.radioshack.com/product/index.jsp?productId=2102736

please help! AA IS way too bulky!!!!
4  Using Arduino / Microcontrollers / newbi question about data sampling rate on: June 29, 2011, 02:59:41 pm
So I am trying to understand how the arduino boatloader works. Does anyone know how to work out how many samples (or is it cycles?) per second is it sending out with these specs;

code for 2 analog channels with an 8 channel mux on each, sent at a baud rate of 9600. So is the deal that the looping code is only sampling the 2 analog pins, and doing some truth table stuff on each pin on both multiplexers, plus any other stuff it has to do in the bootloaded headers etc

Does anyone know how to work this out?

Thanks a lot in advance! f
5  Using Arduino / Microcontrollers / loading sketches via Bluesmirf?? on: June 21, 2011, 07:45:40 pm
I want to remove my FT232R USB programmer from my board and wondered if I can use my bluetooth module to program it instead. Is it possible? The only thing I can see that would be a problem is there isnt a DTR connection on it.... Is there some other way around this? With the FT232R you need a .1uF cap between the DTR and the 1st Arduino pin (RESET, PC6).... but how to do this with a Bluesmirf, I wonder.......

any ideas?
6  Using Arduino / Programming Questions / Re: modify the Wire library to import into my sketch? on: June 19, 2011, 03:04:27 pm
Ah, there it is!

Basically I want to get 3.3 volts into a gyro without needing extra hardware. Below is the original thread. I moved it here since it was going off topic....

http://arduino.cc/forum/index.php/topic,58111.msg420722.html#msg420722
7  Using Arduino / Programming Questions / Re: modify the Wire library to import into my sketch? on: June 19, 2011, 02:38:52 pm
OS 10.6.7
Arduino Alpha 0022
There isnt a folder- just the Arduino app itself in my Applications folder.
No, there is no Wire directory anywhere.....

maybe somehow I made an incomplete installation??
8  Using Arduino / Programming Questions / modify the Wire library to import into my sketch? on: June 19, 2011, 12:13:00 pm
is there a tutorial somewhere on how to find and modify the Wire library to import into my sketch? I want to change the internal Arduino pull-ups so they are not enabled.

Apparently this requires changing two lines of code in Arduino distribution libraries/Wire/utility/twi.c,  but I cant find this twi.c file.....

Can anyone point me in the right direction? Many thanks in advance, f
9  Using Arduino / General Electronics / Re: Arduino Uno on 3.3 volts instead of 5? on: June 19, 2011, 12:01:27 pm
Oh, ok. then AAA's are not good for my project. It seems AA's are the way to go! Wish they told me that in school. I would have saved a lot of money on 9v batteries....
10  Using Arduino / General Electronics / Re: Arduino Uno on 3.3 volts instead of 5? on: June 19, 2011, 11:48:28 am
or even better, I could use AAA's which are even smaller!
11  Using Arduino / General Electronics / Re: Arduino Uno on 3.3 volts instead of 5? on: June 19, 2011, 11:46:11 am
wow. never thought of that! And considering I am using it with a bluesmirf and efficiency with power is important, this is even better. I have already gone through 2 9v batteries just in testing....
12  Using Arduino / General Electronics / Re: Arduino Uno on 3.3 volts instead of 5? on: June 19, 2011, 11:36:22 am
huh. Thanks Lefty. I guess the best way is to just try it and see if I works! Thanks again. But if so, can I still go from 9 volts to the 3.3 voltage regulator?
13  Using Arduino / General Electronics / Re: Arduino Uno on 3.3 volts instead of 5? on: June 19, 2011, 11:34:42 am
oh, I forgot. If this is doable, I can use a 3.3 voltage regulator straight from a 9 volt battery (with the regulating caps on each pin to ground)? Like this one;   http://www.sparkfun.com/products/526

or do I still need to go from 9 volts to a 5volt regulator THEN to the 3.3 one? Sorry. NoooobbBB here... :-(
14  Using Arduino / Microcontrollers / Re: Arduino Uno baud rate change? on: June 19, 2011, 11:27:43 am
OH, I see. so I as mistaken that is needs to be 9600 only. Great! Thanks a lot.
15  Using Arduino / General Electronics / Arduino Uno on 3.3 volts instead of 5? on: June 19, 2011, 11:26:28 am
Can I use a 3.3 voltage regulator to power a board with a ATmega328 Arduino Optiboot (Uno) and expect it to work just as well as with a 5 volt voltage regulator?

thanks in advance, f
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