I need to use a wireless shield along with the duemilanova board.
It's going to need to power up outside -- battery only.
I'd calculate the V/current draw across the board, but yet
to purchase wireless device (likely Xbee or similar). I don't
know what the draw of the two together.
how much life you think I can squeeze out this pup from a single 9V?
how much life you think I can squeeze out this pup from a single 9V?
About 73 seconds.
A AA battery pack or better yet a li-po pack would give you much better endurance. Best to measure the current consumption after you get them all working together and then calculate to determine the mAH you wish to have and then use whatever battery pack that can supply that.
LEfty
How much do you think i could squeeze out a lith-ion?
Could I run it at 3.3v or does it need 5V+ to maximize
the wireless range? Like enough for an XBee or something
off a single battery.
How much do you think i could squeeze out a lith-ion?
Li-po/ion don't come in standard mah sizes, you buy the capacity you need. They also are wired in series strings of 3.7volt per cell nominal voltage, so you would need a 2 or 3 cell pack to wire to the external power plug of an Arduino. I use a small 2 cell li-po from a cheap R/C helicoper. Again any real meaningful battery life requires calculation once you know the actual current consumtion and have determined what you want for discharge time.
Lefty
thanks again
with an arduino, xbee a motor driver(motor powered separately) and a couple of leds, I get a couple of hours out of a 9v battery. I believe that the XBEE with adapter draws upwards of 70ma so the whole assembly might be 150ma.
The 9v batteries really are pretty pathetic but 150ma is quite a lot to draw from any small battery setup for an extended period.
Here's a great article/blog post on the subject:
XBEE Pro Power Req.
Supply Voltage: 2.8 [ch8722] 3.4VDC
Transmit Current: 215 mA @ 3.3VDC
Receive Current: 55 mA @ 3.3VDC
Power-Down Current: <10 uA @ 25 deg Cel.
Arduino Duemilanova Power
Operating Voltage 5V
Input Voltage (recommended) 7-12 V
Input Voltage (limits) 6-20 V
DC Current per I/O Pin 40 mA
DC Current for 3.3V Pin 50 mA
http://arduino.cc/en/Main/ArduinoBoardDiecimila
Power
The Arduino Diecimila can be powered via the USB connection
or with an external power supply. The power source is selected
by the PWR_SEL jumper: to power the board from the USB
connection, place it on the two pins closest to the USB connector,
for an external power supply, the two pins closest to the external power jack.External (non-USB) power can come either from an AC-to-DC
adapter (wall-wart) or battery. The adapter can be connected
by plugging a 2.1mm center-positive plug into the board's power
jack. Leads from a battery can be inserted in the Gnd and Vin
pin headers of the POWER connector. A low dropout regulator
provides improved energy efficiency.The board can operate on an external supply of 6 to 20 volts.
If supplied with less than 7V, however, the 5V pin may supply
less than five volts and the board may be unstable. If using more
than 12V, the voltage regulator may overheat and damage the
board. The recommended range is 7 to 12 volts.The power pins are as follows:
VIN. The input voltage to the Arduino board when it's using an
external power source (as opposed to 5 volts from the USB
connection or other regulated power source). You can supply
voltage through this pin, or, if supplying voltage via the power
jack, access it through this pin.5V. The regulated power supply used to power the microcontroller
and other components on the board. This can come either from VIN
via an on-board regulator, or be supplied by USB or another regulated
5V supply.3V3. A 3.3 volt supply generated by the on-board FTDI chip.
Maximum current draw is 50 mA.
Lith-ion is the way to go it seems.