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Topic: Looking for circuit design feedback (UNO, Two Servos, Proximity Sensor and LEDs) (Read 451 times) previous topic - next topic

creatify

Hello -- new to the forums and fairly new Arduino.

I'm working on a circuit design for a project and would really appreciate some guidance or thought on the circuit layout -- does it appear correct? Most importantly, the power and capacitor layout and any need for resistors? Attached is a fritzing diagram.




Thank you!

dustin02rsx

Your power and grounds are not right. The grounds on the capacitors are right, but you're straight shorting your power supply and hooking up your peripherals backwards.

creatify

Updated images.

Thank you for the quick response! I did see that my ground from arduino was wrong -- I updated that.

I also removed that dc barrel jack to indicate just +/- going into the bread board.

Can you explain '...hooking up your peripherals backwards' ?

Thanks!

dustin02rsx

It just meant the other parts that aren't the arduino. It actually looks like the only thing hooked up backwards is the ultrasonic sensor.

I'm assuming the digital pins are correct.

creatify

Aha, yes, thank you, fixed the image again -- the pins on the LED strip are wired to match what I have currently.


Wawa

On the Fritzing:
"The arduino will be powered via the one 5V 3A power source through it's barrel jack"

Can't do that.
The barrel jack needs at least 7volt, for the onboard regulator to make a stable 5volt supply for the MCU.
Leo..

creatify

Aha - I didn't know that. Can I just wire a USB cable into the 5V line and power the Arduino that way?

Or, I guess I'd need 7V DC power and then resistors between power and the peripherals? The LEDs should be fine on 7V but that may not be good for the proximity sensors and servos.

Wawa

Not wise to power the other devices from 7volt.
You can connect the 5volt supply directly to the 5volt pin of the Uno, bypassing the onboard regulator.

Disconnect before you connect the USB lead to a computer.
The PC  might not like backfeeding 5volt into it's USB socket.
Leo..

creatify

Not wise to power the other devices from 7volt.
You can connect the 5volt supply directly to the 5volt pin of the Uno, bypassing the onboard regulator.

Disconnect before you connect the USB lead to a computer.
The PC  might not like backfeeding 5volt into it's USB socket.
Leo..
I see -- I just need to be darned sure my power supply is regulated, correct? And if I were to power it this way, I'd have power into the 5V pin, and ground into one of the ground pins... but would I still need need a separate ground back to the bread board?

Yeah, I'm being cautious when the arduino is connected to the PC and the rest of the circuit is powered by the DC input.

Wawa

I see -- I just need to be darned sure my power supply is regulated, correct?
Yes, but that also is important for the addressable LEDs.
Leo..

TomGeorge

Hi,
Welcome to the forum.

Please DO NOT keep going back and changing your first post.
In doing so you have made the first 6 posts absolutely misleading and confusing.

Each time you update anything PLEASE write a NEW POST.
This thread may be used by someone in the future to fix their own problem, it is now basically useless as most of the content has been compromised.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Use labels on your connections to servos, sonar, and include your power supply, please don't cross wires at angles, only 90deg please.

Sorry but there is no better CAD package for new users like a pen/pencil and paper.

As a beginner the looks of Fritzy look real schmiko, but it does not convey the necessary info needed for proper circuit analysis.

Thanks.. Tom.. :)
http://www.urbandictionary.com/define.php?term=schmicko
Everything runs on smoke, let the smoke out, it stops running....

creatify

Thank you for the tips, TomGeorge.

I'm not sure if my hand-drawn circuit will be more legible than what I posted via fritzing, but I'm a big fan of pen/paper. I've attached a sample if this helps others that may see issues -- if a hand drawn circuit needs to be more of a standardized 'diagram' I'll have to dig a bit to determine how to modify it. 


TomGeorge

Hi,
Thank-you, that is much easier to read, just need some pin names on the UNO and some polarity signs on the electrocaps.
Also point out the barrel connections, what polarity the inner barrel and the outer sleave of the plug.

Thanks.. Tom.. :)
Everything runs on smoke, let the smoke out, it stops running....

creatify

I'll add as much details as is necessary to get qualified answers! (Versus combing through many different random google findings that only show parts of what I'm looking to do.)

So, I added three power step downs (couldn't I just use one?) to this 'schematic' to ensure I
A) have a solid connection of 7.5V into the arduino
B) knock the voltage down to accomodate 3/4 peripherals.

Seems like by adding these I'm increasing the potential points failure by quite a bit? Maybe that is a reservation I'll have to make being new building these types of circuits.

I'm really looking for a long term stable design here -- I plan to use this exact same circuit on several projects with the only variable being the number of LEDs (which I'll ensure I have enough current to run). I'm decent at soldering and can write the code, but I have a lot of uncertainty and noob in the circuit itself.




kenwood120s

Servos don't have to be controlled from PWM pins: any pins, including the A0-5 pins, will do.

[gumby]I've got my head stuck in the cupboard[/gumby]

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