Hi
I did the Beginners workshop this weekend (really had fun) but we couldnt seem to get the board to work from a 9v battery. We are using the Duemilanove board
We tried the same battery/connection on a different board and thet didnt work either (no LEDs light up)
We put a multimeter on it and we can see 9v is on the solder points behind the power connecter, so it looks ok
Cany anyone help me out with this ?
Thanks, Adrian :-/
Can you tell us a bit more about the battery? Was it a 9V rectangular type with two press studs on top? If so, be warned that the cells inside that kind of battery are tiny -- much smaller than AAA size. That type of 9V batterty is not capable of supplying very much current, posibly not enough for the Arduino and whatever else (LEDs, etc.) that you had wired to it.
In what way did it not work?
Yes it was a square 9v battery (NM 1694)
So it doesnt have enough current then? I thought it must be something basic as Im very new to this and we tried it on two boards - none of the onboard LEDs even lit up
So should I be using 6 x AA batteries then ?
Thanks so much for the quick reply
Ade
Worth trying a pack of six AA size cells, yes. Make sure you have the correcy polarity, negative (black wire) to Ground and positive (red wire) to Vin.
The Vin will be the certre pole of the connector?
Yes it is.
Hi Ade! This is Spike! Not much consolation for you I guess, but my Duemilanove runs the "Blink" example running from a 9V Duracell Plus (other batteries are available) MN1604.
Measuring the current shows around about 30mA - poss a bit high for a MN1604 (PP3) but should run for a bit. I regularly drive circuitry at 100mA plus from PP3s.
Please feel free to PM me if you wish.
Spike
I am having similar problems with the duemilanove.
I will need to power it from battery eventually but for the moment i am trying to power it via an external power supply. I have tried connecting it to both the female power socket and the gnd+Vin pins but nothing happens with either compared to when its connected via USB.
Is it possible to connect the power leads directly to usb when its not in use?
What type of battery are you trying to use? I'm looking at the circuit (schematic) diagram (http://arduino.cc/en/uploads/Main/arduino-duemilanove-schematic.pdf) ATM. Do you have a multimeter or similar voltage measuring instrument to hand?
Spike