Go Down

Topic: Powering nano and stepper from single supply (Read 215 times) previous topic - next topic

setiawanj

Hi guys!

I've currently got my Nano powered via USB, and my 28BYJ-48 stepper motor powered by 5V 1A DC supply plugged into the wall.

Say I wanted to power both of them via a single DC supply, how would I go about doing that? I have very poor understanding of electronics (can barely decipher a schematic), so descriptions in terms of 'wire goes from here to here' would be more helpful.

My assumption is that it would be something simple like, positive from the DC supply being split to go to Vin on the nano and to the 5V input on the stepper driver, and likewise for ground (negative from DC supply to both GND on nano and stepper driver).

Is this more or less correct? Do I need a capacitor or resistor somewhere (and if so, what rating)? Do I need a higher voltage or higher current power supply than 5V 1A?

Any help would be much appreciated. Thanks!

Paul_KD7HB

Hi guys!

I've currently got my Nano powered via USB, and my 28BYJ-48 stepper motor powered by 5V 1A DC supply plugged into the wall.

Say I wanted to power both of them via a single DC supply, how would I go about doing that? I have very poor understanding of electronics (can barely decipher a schematic), so descriptions in terms of 'wire goes from here to here' would be more helpful.

My assumption is that it would be something simple like, positive from the DC supply being split to go to Vin on the nano and to the 5V input on the stepper driver, and likewise for ground (negative from DC supply to both GND on nano and stepper driver).

Is this more or less correct? Do I need a capacitor or resistor somewhere (and if so, what rating)? Do I need a higher voltage or higher current power supply than 5V 1A?

Any help would be much appreciated. Thanks!
Welcome to the Arduino forum. That question has been asked so many times.

Measure the voltage of the 5 volt supply then again when the stepper motor is running. If there is very little difference, then you can power the Arduino from the same supply. No other components are needed.

Your DVM will not show rapid changes in voltage, but if they are present, your Arduino may have problems, but try it and find out.

Paul

groundFungus

#2
Jul 22, 2019, 06:59 pm Last Edit: Jul 22, 2019, 06:59 pm by groundFungus
Quote
positive from the DC supply being split to go to Vin
If the power supply is well regulated 5V,  connect to the 5V, not Vin.  The voltage to Vin needs to be greater than 7V to ensure that the 5V regulator has enough voltage to properly regulate.

JCA34F

And buy yourself some of these to break the adapter barrel plug out to wires.
Barrel plug to screw adapter

setiawanj

Thanks everyone!

I don't currently have a multimeter.. I guess it would be wise to invest in one.

Thanks @groundFungus for the tip on 5V vs Vin. The DC adapter I have doesn't say anything about 'regulated', so I'm guessing it's not regulated. Something like this, then is what I need?

https://www.jaycar.com.au/7805-5v-1a-voltage-regulator-to-220-case/p/ZV1505

Also, I'm assuming this goes after the split from the power supply (so it's only relevant to the Arduino), and not before the split?

There's also this thing, but being variable voltage, I'm worried I'll accidentally bump it and fry my Arduino.. https://www.jaycar.com.au/arduino-compatible-dc-voltage-regulator/p/XC4514

@JCA34F The nano doesn't have such a barrel so can't do that unfortunately. Maybe I can splice up a mini usb cable, and connect the DC 5V to that? That way it would use the board's built-in regulator.

Thanks again everyone :)

setiawanj

#5
Jul 23, 2019, 12:08 pm Last Edit: Jul 23, 2019, 12:09 pm by setiawanj
Okay! I've got a diagram now. The plan is to use a 9V 500mA DC supply. 9V into Vin on the Nano, and use a LM7805 regulator to turn the 9V into 5V for the motor so it doesn't overheat.

Does this look okay? The motor shouldn't draw more than 100mA if I'm not mistaken. The LM7805 says it has a rating of 1A though, will it matter that I'm feeding it only 500mA?

I intend to use `INPUT_PULLUP` for the switches, hence the lack of resistors on them.

Thanks again!

Go Up