I want to create a project where I need 4 servo motors and the Transceiver NRF24L01+Antena.
The problem is I don't know a lot about electricity and I am facing a problem now.
I know that the I/O pins can act as a GND pins or 5V pins.
After searching for a little it says that the pins can handle 40mAh.
And the servo motors draw about 100-250mAh.
So I don't know if it is possible to connect the servo motors and the transceiver with Arduino like this.
Note that I will be using Uno R3 which have 2 5V pins and 3 GND pins.
If that doesn't work, do I need to separate the servo motors supply or use another Arduino.
keep in mind that I am willing to use as less batteries as possible for my project.
I know that the I/O pins can act as a GND pins or 5V pins.
Wrong. They are signal pins, it just so happens that the signal level can be 5V or GND
After searching for a little it says that the pins can handle 40mAh.
that's 40 ma(not mAh, time is not involved) is a maximum rating; a better design goal is 10 ma.
And the servo motors draw about 100-250mAh.
(ma); and you'll be lucky to find one that draws that little if it stalls out.
So I don't know if it is possible to connect the servo motors and the transceiver with Arduino like this.
possible, yes, but doomed to failure. For servos, you need to provide an external 5VDC supply; you then connect the +/-sides of that to your servos. You also MUST provide a wire from the - of the external supply to any one of the GND pins on the Arduino. That provides a reference level for the output signal from the signal pin of the Arduino, which connects to the third pin(green).
You will also want to use that external supply for your NRF24L01.
This is all necessary because the built-in 5V power of the Arduino is EXTREMELY LIMITED.
Note that I will be using Uno R3 which have 2 5V pins and 3 GND pins.
If that doesn't work, do I need to separate the servo motors supply or use another Arduino.
keep in mind that I am willing to use as less batteries as possible for my project.
Batteries??? This gets worse. Suggestion - make it all work on a stable, decent power supply, then start messing with batteries, that will induce a whole different level of pain.
C
Thanks for correcting all the wrong info I had.
So basically I need to separate the power supply for the servo motors and the Arduino.
But I don't see a problem with batteries or supplying another source for the Transceiver.
I know that I need to connect the + side of the battery with the VIN pin in Arduino and the - side of the battery with the GND pin in Arduino.
But why do I need to separate the Transceiver?
That kind of transceivers uses from 1,9 V to 3,6 V. https://lastminuteengineers.com/nrf24l01-arduino-wireless-communication/
And the site says I need to connect it to the 3,3 V pin in Arduino. ... Which means I don't need to separate it's power supply.
Edit : I have connected the servo motors as you explained. Hope I understood it right.
Your servos likely need five or six volts, but certainly not nine. What sort are they? Also, those little nine volt batteries can't provide nearly enough current for servos - use a set of AAs instead.
As to the radio, it seems to be very low power so it may be ok on the Arduino 3V3 pin but be aware that there is very little current available on that pin.
Yes I know that the servos don't need that much volts. I just couldn't find a 5v battery on the website.
So if the pin has a low current, what is the worst case scenario that could happen while communicating with a transmitter? Or is it not going to work as expected?
Edit : I re-checked the website and the modules max operating current is 13,5 mA.
and after googling What is the maximum output current of 3.3 V pin? It says its 50mA.
Even the site itself showed the pin layout of the module and connected it to Arduino board.
Then it sounds like, once your servos have separate power, the radio will be fine on the 3V3 line. I'd verify that without anything else connected first though.
One thing missing is the ground to the Arduino. It might seem obvious, but the servos and the Arduino must share a ground or the signals cannot be properly sent to the servos.
Edit: looks like you used red for a ground, connect the power from the battery to the Arduino too
I used the red wires for VCC and connect the servos with the battery.
And used the black wires to connect the servos GND with the battery, and the pink wire connects the batteries - with the GND.
And the green wires for signal.
The maximum volt the servos can handle is 5 or 6 Volt.
While the recommended Arduino voltage supply is 7-12 Volts.
So how can they have the same battery?
So I can connect a batteries + side to the Arduino's 5V pin as an input?
There is sites that tells me that if I supplied Arduino with 5Volts the 5 Volt pin output wont be stable.
Therefore the 5V pin wont supply 5V.
I haven't used any 5V pins as an output in my project so far so I guess that's not a problem
Note: The servos exploded in the previous image because the volts were 9.
Now I have connected the same 9 Volt battery but this time its connected with the 5V pin in Arduino.
And it did not explode
Any explanations? Will this work irl without any damages?
Or should I just stick to 5V battery?
I tried a 5 Volt battery on the site but couldn't run the simulation.
The battery was a lemon battery
If you're going to power via the 5V pin, you need a stable regulated voltage. If you're using something as variable as a lemon battery (Zinc & copper electrodes?), you'll need to use Vin and as you suggest, 9V there is acceptable.
Probably not. The Arduino wants stable power at 5V plus or minus a little bit. If you have a nice big battery that can provide five or six amps, that would be fine.
The problem is that servos pull quite a bit of current and a small battery is likely to have voltage sag when they do and will cause the Arduino to brownout. IIRC, lemon batteries produce tiny current, so you would need a huge array of them to power this thing.
