Hi there. I am building a monitoring system that uses 5 sensors, an LCD, a buzzer, a Wi-Fi module and a GSM module on an Arduino UNO. Everything works fine except that due to the high current drawn from the Arduino, the voltage regulator heats up a lot. So I thought of providing a separate power supply to all the electronic parts.
My question is, is it possible to connect all the VCC and GND pins of all the electronic parts to a separate power supply such as a buck step down converter and connect only the data pins to the Arduino? Will this work or will blow out any of the sensors or Arduino?
Or else if there is any other way of powering up my system pls feel free to comment. My maximum current usage including the GSM module is around 2.7A.
Thanks in advance.
is it possible to connect all the VCC and GND pins of all the electronic parts to a separate power supply such as a buck step down converter and connect only the data pins to the Arduino?
No. The GND of the Arduino must also be connected to the other GND pins, as it defines 0V for the data pins.
You can use any number of power supplies, but grounds must always be connected. The only exception to this rule is when using optoisolators to transmit data signals. At the very least, use a separate power 3-4A supply to power both the WiFi and GSM modules.
Yes you can use "one big" 5V power supply (assuming everything works on 5V) or separate power supplies. Make sure the grounds are connected together so that everything shares a common ground.
Connect to the 5V pin instead of Vin to bypass the built-in voltage regulator.
Put three 7805’s in parallel.
Put three 7805's in parallel.
It is never a good idea to connect voltage regulators in parallel, as they will disagree on the output voltage and perhaps even oscillate.
Even if cap’d right? And a heat sink?
LandonW:
Put three 7805’s in parallel.
Voltage sources don't work in parallel. You could trash an entire circuit that way.
@MarkT
For my education and whom ever else might read this..... why?
jremington:
No. The GND of the Arduino must also be connected to the other GND pins, as it defines 0V for the data pins.You can use any number of power supplies, but grounds must always be connected. The only exception to this rule is when using optoisolators to transmit data signals. At the very least, use a separate power 3-4A supply to power both the WiFi and GSM modules.
So will 2 step down buck converters do the job? One for the sensors and LCD and another for the GSM and Wifi module. Since it can supply upto 3A each. As long as I connect all the grounds to the Arduino it should be fine right?
DVDdoug:
Connect to the 5V pin instead of Vin to bypass the built-in voltage regulator.
Is it possible to power the Arduino using the 5V pin? I thought it was only to give a 5V output.
Is it possible to power the Arduino using the 5V pin?
Yes, we do it all the time.
For my education and whom ever else might read this..... why?
What do you think will happen when two voltage regulators are connected in parallel, each attempting to maintain the output voltage at a different setting?
ZakirJ:
Is it possible to power the Arduino using the 5V pin? I thought it was only to give a 5V output.
In fact, it is the only alternative to using the USB connector and indeed, the proper way of powering the Arduino. It is not really for an output at all, though it can be used as a reference voltage.
The USB port has in a UNO, a polyswitch to protect it from supplying more than 500 mA, and a diode in the Nano to isolate the USB to serial chip. In either, the on-board regulator is essentially useless as it can only power the microcontroller itself and a few LEDs at 20 mA.
jremington:
What do you think will happen when two voltage regulators are connected in parallel, each attempting to maintain the output voltage at a different setting?
Well, the one with the higher voltage will provide up to its current limit, then the voltage will drop to the next highest as it "takes the load".
The problem is twofold - they will not share the load equally and you do not want to run regulators at their current limit - and without sufficient output capacitance, there is a risk of instability and oscillation.