arduino uno power

hi guys,

i have connected 3.3v and 5v ports to accelerometer and temperature sensors to arduino uno, i needed to connect bluetooth reciever(3.3v). please guide me. thanks a lot. =)

i needed to connect bluetooth reciever(3.3v).

How much current does it take. The 3V3 on an arduino is only good for 50mA so it looks like you will have to use a 3V3 voltage regulator and use the 5V line to power your bluetooth device.

I think the Uno uses the same regulator as the Mega http://www.digikey.com/product-detail/en/LP2985-33DBVR/296-18476-1-ND/809911 and its good for closer to 150mA but will get very warm providing that much.

A bluetooth module like this one needs 50mA http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Wireless/Bluetooth/Bluetooth-RN-42-DS.pdf

Others need more, up to 100mA http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Wireless/Bluetooth/rn-41-ds-v3.41r.pdf

(both found at Sparkfun)

so more than likely a seperate 3.3V regulatur will be needed to support all your components.