There was a reason we chose the mini pro, but can't remember it now. Maybe price, or something, I don't know I've slept since then lol, mini pro was a conscious decision though.
Right, so I've been advised previously in this thread to buy a power source greater than 5v.... Now I'm being advised to regulate it back to 5v after buying one of a higher value. This confuses me. Why bother buying higher value?
ALSO...
Why can't I just keep the same setup I have now and just have the servos pos and gnd connected directly to arduino? It's working absolutely fine from USB power through arduino to servos, so why would battery power be any different? Been advised countless times to power them externally but nobody has said why.
1.) the voltage regulator on the Arduino (at least on the Duemilanove/Unos) its +5v regulator.. (meaning you need MORE than +5v to power it.. they recommend 7-12.. but you 'can' use +6v at a minimum)
2.) Your servo(s) do NOT have any sort of voltage regulator... (and they are rated (usually) for +5v tops.. some maybe a bit more..(have to read your specific servo spec sheet), which is why you are being told that if you want to attach a battery pack DIRECTLY to the servo.. make sure the voltage is regulated correctly to be with-in its specs.
A.) being plugged into your USB hub might be causing extra 'noise' on the planes.... this is ALSO a regulated power source form the hub as well..
(solid +5v)
a battery its NOT solid +5v... and in fact you need MORE than the voltage regulator to power it.. ... once your battery pack falls below (about) +6v the Arduino wont work anymore.. the voltage drop across the regulator and the project itself will drain the battery a bit. (this is why you are told to get a battery above +5v.. its what everyone and the Arduino site says to do)
And the suggestion about WHY using external power has been commented on.
1.) The Arduino board can ONLY do'give so much.. (it has limits).. MANY compoennts need MORE than what an Arduino can delivery in terms of current..
Arduino = 20mA (40 max) per pin.. and only (I think 200mA in total)
When you servo works/runs.. it pulls current.. (they say usually 1 servo hooked up if fine..if you use more.. try powering things from external battery source).. if the servo or motor is under load.. it may pull more (maybe even more than the Arduino can safely give and possibly ruin the Arduino permanently)
2.) could help on noise reduction... as well as moving away form the USB power.. and finally getting OFF the breadboard test bed.. (these can all lead to 'noise' in your circuit)
If you want to drive the servos' from the Arduino.. all wires go tot Arduino (none to battery pack)..
V++
GND
Control line
...all go to Arduino pins.
If you want to power from battery pack..
V++ on servo goes to battery pack (make sure the battery pack is regulated to a voltage the servo can handle)
Control pin goes to Arduino
GND goes to battery pack GND
(also make sure the GNDS on the battery pack/arduino/servo are all connected.)
Question:
looking forward... how wold you keep USB power? IN the end you need to use a self contained battery source..right? (cant keep your costume plugged into a computer)
I think removal of USB power
cleaning up the final test bed form the breaboard
will help in things..
maybe post a pic of your current/final wiring?? maybe we can see something that was overlooked?
