powerning my project?

hello, I am using arduino nano v3.0 (328 if it matters), controlling 2x 4051 multiplexer, a 4094, a 16x2 lcd with backlight, 2 x irf540 transistors, a buzzer, 4x lm335, and 2x hall switch..... I am powering all that through arduino vin, and when using 12v the voltage regulator becomes hot, so i tried 8v, and it is a little cooler...

Is this ok solution for powering all that, and the heating is normal, or would it be better(smarter) to use a external 5v regulator, and connect it to the 5v pin on arduino, and thus to all the other 5v...?

about heat & voltage regulator, check out this thread: http://arduino.cc/forum/index.php?topic=106232.0

imo, if it works, it works. However if you want to use additional power and have a regulated power source, I would use it to directly power some of your components. Connecting a power source to the power pin sounds like a bad idea to me.

if i would use a regulated power source, i would not use the power over the vin pin, so the only power supply would be the regulated 5v, connected to the 5v arduino pin, and all the other 5v "inputs" which are all connected..

ok, and how is the arduino powered?


its just not a smart idea. for the whole thing to work, you still need a common ground... and then all of a sudden you have +5v flowing the wrong way into your Arduino. I dont really know what would happen, but I suspect it might involve blue smoke.

Why not just power your electronics directly via your 5v source?

The Arduino Nano can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source.

ok. your right and I'm wrong.

I once fried an Arduino under similar conditions, that's why I am recommending you don't do it.

I have found that if the Arduino is not moving (being plugged into the wall) then it is best to go with a 5 volt USB adapter phone charger. You can plug the USB cord of your Arduino into the USB Charger.

it is moving... This is on a e-bike.

I Would use 4 rechargeable Energizer AA batteries, the rechargeable batteries will peak at 1.3 volts putting 4 of them gives 5.3 volts on full charge and 4.9 on low battery. You can attach these directly to the Arduino +5 and ground as the Arduino is okay working on 5.3 if you wanted to you could even add a diode to lower it to 5.2 if you have sensitive equipment. I use 2 packs hooked up in parallel and can get 4 amps out of them.