Double checking correct power supply/wiring

I am beginning my first project using power from a line cable rather than USB through an arduino itself. I have an RS-15-5 power supply that outputs 3 amps.

My plan during prototyping is to run the power supply to the breadboard and an out from the breadboard to the Vin and ground on an arduino uno wifi V2. I will then have three runs of addressable leds powered by the breadboard and the data pins from each will go back to digital pins on the arduino. At some point I will be wiring up a motion detector and an MP3 Player.

But my main worry is wiring the power incorrectly. Will I fry my arduino with the above setup? Is there any power concern about the digital pins if I'm only using them for data?

Thank you.

That looks like a 5v power supply. You can’t feed 5v into Vin. Recommended input for Vin is 7-12v for an Uno.

I had read, and forgotten that about the Vin. I could use an rs-15-12 solving the issue with powering the arduino but then I would have to step down to 5v for the led strings and everything else I connect to the breadboard. What am I missing here?

run the power supply to the breadboard and an out from the breadboard to the Vin and ground on an arduino uno wifi V2.

Connect it to ground and the 5V pin, not Vin.

I will then have three runs of addressable leds powered by the breadboard and the data pins from each will go back to digital pins on the arduino.

How long are the runs of LEDs? How much current do they draw? Your basic idea is OK but the problem is you might be passing too much current through the breadboard. Breadboard is not designed to carry large current. I would think maybe 1A absolute maximum, maybe not even that. Unless the LED strips are very short give them their own wires back to the power supply. Each strip should have its own connection.

Will I fry my Arduino with the above setup?

No, because the current isn't flowing through the Arduino. You might suffer from poor connections, low voltage and damage to your breadboard.

PerryBebbington:
How long are the runs of LEDs? How much current do they draw? Your basic idea is OK but the problem is you might be passing too much current through the breadboard. Breadboard is not designed to carry large current. I would think maybe 1A absolute maximum, maybe not even that. Unless the LED strips are very short give them their own wires back to the power supply. Each strip should have its own connection.

They are a neo pixel knock off with good tolerances. And I am planning on running 1 run at 16, 1 at 10, and 1 at 4 or 6. 8 hadn't considered the issue with running too much power through the bread board. Is it safe to drop multiple power lines back to the same power supply port? They are the screw down type, but that doesn't seem safe to me.

In terms of safety, I think the least of the issues are your DC connections. For ease of tying everything together, you might use a bus bar or barrier strip to link everything up. But it's only 5V at 3amps on DC, so nothing to worry about there.

HOWEVER... one potential safety issue that jumps out is the fact that the power supply you mentioned takes AC in via bare screw terminals. So you want to think about making sure your high-voltage AC side and wiring is safely managed in terms of secure wiring, enclosures, access by curious hands, etc.

steve20016:
In terms of safety, I think the least of the issues are your DC connections. For ease of tying everything together, you might use a bus bar or barrier strip to link everything up. But it's only 5V at 3amps on DC, so nothing to worry about there.

HOWEVER... one potential safety issue that jumps out is the fact that the power supply you mentioned takes AC in via bare screw terminals. So you want to think about making sure your high-voltage AC side and wiring is safely managed in terms of secure wiring, enclosures, access by curious hands, etc.

Thank you. I will look into a bus bar. As for the ac side, by the end of this, I'll be mounting everything in a project box. Hopefully that should stop anyone from touching anything. This unit will eventually hang on the wall in my office.

This is your data sheet for the series of PSU you plan to use. Just keep in mind and follow the Terminal Pin No. Assignment shown in the data sheet. Once you have things wired and ready give it all another once over just to make sure you're not in for any unwanted surprises. You will do just fine and pay attention to what you were told as to where to connect your external 5 volts to your Arduino board.

Personally for the PSU I would likely use spade lug connectors which are available just about anywhere from home improvement stores to auto parts stores and a better choice is the ring style. The crimp tools are cheap and use lugs sized for your wire gauge.

Also this like most power supplies has a plastic barrier over the terminals. Nice feature and always leave it on. Thus nothing of consequence is exposed.

Ron

You always have the option of using a good quality 5v wall-wart power supply and strip off the barrel jack and land the + and ground on bus bars inside the project box.
Something like this:

That way, don't have to muck around with AC connections. I would personally go this route if it were my project.

steve20016:
You always have the option of using a good quality 5v wall-wart power supply and strip off the barrel jack and land the + and ground on bus bars inside the project box.
Something like this:
Pololu - Wall Power Adapter: 5VDC, 3A, 5.5×2.1mm Barrel Jack, Center-Positive

That way, don't have to muck around with AC connections. I would personally go this route if it were my project.

Maybe I am misunderstanding but I don't think that will work 8n my case. I am powering the arduino and 32+ leds. My power supply will have to be able to handle both the arduino and the strings of leds.

Calculate how many amps you need and go from there.

The wall wart I linked to provides the same number of amps (3A) as the device in your original post. So it does the same thing.

Do you have a bench supply (or can you hack something together using a digital multimeter) to measure how much current your LED strips draw?

Whether you get a panel mount supply like the one in your first post or a wall wart — they all are capable of supplying some set amount of current. As long as it’s greater than the current requirements of your project you are good to go.

Edit: just noticed this in your original post. You should get estimates of the current requirements for these components as well, if you plan to power them from the same supply.

At some point I will be wiring up a motion detector and an MP3 Player.

Ron_Blain:
[
Personally for the PSU I would likely use spade lug connectors which are available just about anywhere from home improvement stores to auto parts stores and a better choice is the ring style. The crimp tools are cheap and use lugs sized for your wire gauge.
[/quote]

Do you mean that I could stack the ring style connectors to have multiple runs out to various components? For example, 3 rounds to led strips, one run to the breadboard, etc.

Or do I need some other barr style connector? I am not familiar with using those.](https://www.alliedelec.com/m/d/dd2718f3d2fe7c9e368d3258b2ba7306.pdf)

steve20016:
Edit: just noticed this in your original post. You should get estimates of the current requirements for these components as well, if you plan to power them from the same supply.

I will he checking this again and again but I have calculated a need for 1.92amps 9.6 watts for the led's. The MP3 Player and its two 3 watt speakers are the only thing I haven't really measured yet. Though I am also concerned about the actual usage of the components. As I understand it, they can use up to 20% more than what's advertised at times. If that's the case, my 15 watt power supply would not be enough.

one run to the breadboard, etc.

I think with the idea of the busbars/barrier terminals etc, we are all strongly steering you in the direction of totally getting rid of the breadboard for your final project implementation. Heck, you could even make connections with wire nuts. But just don't use a breadboard in the final project!

The MP3 Player and its two 3 watt speakers are the only thing I haven't really measured yet.

Do you know what unit you'll be using? Can you post the model/links? Also, does it run on 5V like everything else in your project?

steve20016:
Do you know what unit you'll be using? Can you post the model/links? Also, does it run on 5V like everything else in your project?

Here is everything in the project I haven't linked thus far. Sorry for any formatting issues. I'm posting from my phone.

HC-SR501 PIR Sensor Infrared IR Body Motion Module for Arduino Raspberry Pi(Pack of 5pcs) https://www.amazon.com/dp/B07KBWVJMP/ref=cm_sw_r_other_apa_i_KoOyEb5D4Z4W3

Aideepen YX5300 UART Control Serial MP3 Music Player Module for Arduino/AVR/ARM/PIC https://www.amazon.com/dp/B01JCI23JG/ref=cm_sw_r_other_apa_i_aoOyEbW1R4M1E

CQRobot Speaker 3 Watt 8 Ohm for Arduino, JST-PH2.0 Interface. It is Ideal for a Variety of Small Electronic Projects. https://www.amazon.com/dp/B0738NLFTG/ref=cm_sw_r_other_apa_i_YlOyEbPPQ36RX

5PCS 200 Times Gain 5V-12V LM386 Audio Amplifier Module for Arduino EK1236 https://www.amazon.com/dp/B01FDD3FYQ/ref=cm_sw_r_other_apa_i_EeOyEbPZ5KHKH

eBoot 30 Pieces Photoresistor Photo Light Sensitive Resistor Light Dependent Resistor 5 mm GM5539 5539 https://www.amazon.com/dp/B01N7V536K/ref=cm_sw_r_other_apa_i_8oOyEbG6BCCVG

Hi Joerdie,

Sorry, I've been out, it seems that you have had lots of good answers since you asked me about multiple connections to the PSU. I have nothing useful to add.

Hmmm, I think you're right on the cusp with 3A. Others with more experience could lend better perspective here.

But I see in your OP that you're using the wifi Uno board, so that could use a lot of current. Say you budget 1A worst-case for the Uno wifi board, and add 1.96A from your LED measurements, you're already at 2.96A without the other components. Again, say average worst case 100 mA per component, you'll need 2 amplifiers (one for each audio channel), the PIR, and the MP3, that's another 400mA. Best case here might be 50mA per component perhaps and 500mA for the Uno wifi? But that's putting you close to your limit.

If you aren't using wifi, you might be okay on 3A. But if you're using wifi, it'll be close. A 5A supply might be the way to go

If you have an existing power supply to play with, you always just hook everything up and see how it measures, and then acquire your final supply based on those results. But flying blind, I'd go with a 5A supply.

joerdie:
I will he checking this again and again but I have calculated a need for 1.92amps 9.6 watts for the led's. The MP3 Player and its two 3 watt speakers are the only thing I haven't really measured yet. Though I am also concerned about the actual usage of the components. As I understand it, they can use up to 20% more than what's advertised at times. If that's the case, my 15 watt power supply would not be enough.

Once you pretty much know your power consumption allow an overhead in choosing your supply needs. I like numbers like 20% ~ 25% so you have a comfort zone. I estimate I will need a 4 amp supply so I get a minimum 5 amp supply. Keep in mind also the Chinese amp has never been the same as my amp. :slight_smile: Most of the low cost, low end stuff you get what you pay for.

Ron