I’m attempting to reduce a 8.5v power source to 5v with a regulator module, to power a Nano and a servo.
The Nano works fine with the 5v feed, but as soon as I connect the servo (taking about 350ma) the Nano stops working.
Attached is a diagram of this, forgive the crude nature of it.
When I connect the Nano to an independent power source (with a common GND) everything works fine, so it seems that the servo is pulling too much current. But this confuses me as the Nano should take 40ma(yeah???), and the servo 350ma. The output of the regulator is 800ma, so it SHOULD work, but doesn’t.
Presumably I can use a second regulator, but I’d like to understand what’s happening here.
I’m very much a newbie so all help is greatly appreciated.
Hello xfpd, the lights are not connected yet.
But I reckon, having done some further testing, that my assumption that the servo is drawing 350ma might be wrong. I took this from the reading on my bench power supply which briefly spikes to 350ma, but I think this is an underestimate.
Andy
Even the smallest servos can require up to 1 Ampere to start moving, then after a few milliseconds, the current draw drops. Larger servos like the MG996R require 2.5 Amperes or more to start. Look for the "stall current" servo specification on the data sheet.
It is always best to power the Arduino and motors or servos separately.
Yes, they are. We can see that they are, from the diagram you posted. The diagram you posted represents the circuit you are asking for help with, doesn't it? Would you go to your doctor or car mechanic and misrepresent the situation to them?
Just because the advice you get on this forum is free, does not mean you can treat that advice as worthless. You owe an apology to @xfpd and @jremington.
@brooko67 there is a problem with the button in your circuit. When the button is not pressed, the pin D2 is floating and could read HIGH or LOW randomly. If your code (which you forgot to post) uses mode INPUT_PULLUP, then it won't be a problem. But in that case the 10K is not required at all, and could even cause problems.
Your Nano 3 has a built-in regulator, which maybe will allow the Nano to operate normally when the servo is activated. Connect your 8.5V supply to the Nano's Vin pin to take advantage of that.
Not solving your problem but based on the wiring diagram in the opening post your switch seems to be wired incorrectly.
If you use the internal pull-up, you don't need the 10k resistor; if you don't use the internal pull-up you have a floating input when the swicth is open.
Now that I've bypassed the VR and powered the Nano directly from the 8.5v source, does this mean that I have to address the issue of the GND now not being common to the servo and the switch? Is this correct? Can i simply connect the GNDs together? If you're able to help then I can supply a new diagram.
