program stops after disconnecting from computer

i have a new arduino uno and a i noticed that the program stops after disconnecting from computer. i am programing it on a mac 10.6 and powering it with a 9 volt rechargeable battery by makeing this http://www.arduino.cc/playground/Learning/9VBatteryAdapter

has someone had this problem before?

Other than a 9 V battery, what is connected to the board?

legoaceking: i have a new arduino uno and a i noticed that the program stops after disconnecting from computer. i am programing it on a mac 10.6 and powering it with a 9 volt rechargeable battery by makeing this http://www.arduino.cc/playground/Learning/9VBatteryAdapter

has someone had this problem before?

With the arduino unplugged from USB but with battery plugged in measure the voltage between the Vin pin and ground pin and tell us what you read. I suspect you have too low a battery voltage. Those small 9vdc batteries are almost useless for arduino useage as they have very low current capacity.

Lefty

after disconnecting from the computer just the 9 volt battery. in the program i use the led connected to pin 13. how much voltage does the Arduino uno use?

how much voltage does the Arduino uno use?

In your case, it is not a question of voltage (9 V is fine) it is a question of current. A 9 V battery has very little to offer.

@retrolefty's test will determine if you are trying to draw too much current from your battery. It will also determine if the battery is near dead.

before i did that i noticed that the 9 volt rechargeable battery that i was using did not give off 9 volts. on the battery itself it said below 9 volt part in small text "7.2V-150" mAh. can someone tell me how much power the arduino uno needs?

legoaceking: before i did that i noticed that the 9 volt rechargeable battery that i was using did not give off 9 volts. on the battery itself it said below 9 volt part in small text "7.2V-150" mAh. can someone tell me how much power the arduino uno needs?

After having to go through the series polarity protection diode, 7.2vdc is just at the threshold of the auto-voltage selection function for the board. I would suggest that one needs at least 7.5vdc at the external power connector to reliably trigger the board's auto-voltage selector switch.

So you need a higher voltage if you want to utilize external voltage connector to power your board, 7.2vdc doesn't cut it. And a small 9vdc barrey (even if providing 9 volts) is still a poor choice to power an arduino board because of the low current capacity they offer.

Lefty

what would you recommend to power my arduino uno?

If you'd like a satisfactory answer, you will have to provide a description of your intended application. At this point, the best choice for power is the USB port.

legoaceking: what would you recommend to power my arduino uno?

Something like this maybe:

http://www.sparkfun.com/products/298

what would you recommend to power my arduino uno thats is portable?

I would recommend 4 1.5 volt batteries. It should provide enough current, and in my opinion 9v batteries are a ripoff anyway.

This probably doesn't apply to many people, but when I used my nxt in conjunction with my arduino, I found that my rechargeable lego battery could power both at once. Also, 6 batteries worked, though it may not be recommended to use 12 volts.

zonedabone: I would recommend 4 1.5 volt batteries. It should provide enough current, and in my opinion 9v batteries are a ripoff anyway.

No, 4 1.5 volt batteries equals 6 volts, that is not enough voltage for the external power connector and too much for direct connection to the +5vdc pin, as the AVR chip has a 5.5vdc max voltage limit. One would need to use 6 AA cells if using the external power connector.