Hi. I'm making a project in which I have to use a 5v external power supply (stripped usb cable which i soldered pins to connect 5v and gnd). I tried using those USB phone chargers and it works great. I need to find a way to power both the arduino and that 5v power supply with the less space possible. I tried to connect the arduino to one phone charger and the power supply to another one, that seems to work fine but i need it to be smaller. Can i use those double phone chargers like this one:
This has one port with 1A and other with 2.1A. One port would be for the arduino and the other one will be for the supply. I dont have much experience with this yet so i want to be as careful as possible. I assume that i should connect the 1A to the arduino and the other one i guess there wouldnt be problem with amperage, is that right? Let me know
Thanks
I think you are getting ahead of where you should be. What is in your project and how much current does it require worse case and at what voltage. Motors draw several times there current rating when starting. You can check this out: https://www.aliexpress.us/item/2251832800460315.html? This will give you more current.
For a Nano you can use one power supply and feed it to the external hardware as well as the 5V pin of the Nano. You will still have the option to connect the USB to your PC.
For the Uno/Mega the same applies but it's not advisable to use both 5V on the 5V pin and USB at the same time.
I need to power a MAX9814, DFPlayer Mini and a MicroSD Card module. I am afraid that the 5v pin is not enough so I stripped a USB cable, took the ground cable and connected it together with the arduino gnd, and power those three devices with the 5v cable from the USB I stripped. It works just fine but I am looking for a definitive way to do it, without a breadboard, so I will use a phone charger like the one I posted originally. What do I need to know in terms of amperage? Can I connect the arduino to the 5v 2.1A port or should i do it with the 1A? If I use the arduino with one port, the other will be for the USB power supply, will it work either way with 2.1A or 1A depending on which one the arduino needs?
Finally you provided some more relevant details, but not yet all. And my crystall ball is not working today.
Which speakers or headphones will play the music? What is their power consumption.
And which Arduino model? there are many with different power consumptions.
What you have to do is calcultate the maximum power consumption of all those devices in the worst case. Check the datasheets of all them.
But as a first approach, an arduino mini would need a few mA, the MAX9814 a few mA more. The DFPlayer Mini can consume about 50mA if I'm not wrong. The SD card other 100mA maybe?
Earphones usually consume less than 100mA, I think. But in the worst case with speakers it would be the 3W mentioned in the DFPlayer datasheet divided by 5V => 600mA.
So I understand that with a single phone charger of 2.1A or even 1A could be enough for all together.
Of course it all depends on your devices. If you connect a pair of speakers like the ones in the Maracana Stadium, then maybe 2A will be not enough.
After the calculations you can try and see if the music plays.
You can use a (5V) charger to power via USB; you can in that case also power external components from the 5V pin. For an Uno, there is a fuse on the board to protect the USB port of the computer so there are limitations (500 mA total).
What you should not do is apply 5V to the 5V pin and at the same time apply 5V via the USB port.
