I am currently using two Arduino UNO, but in the future, I will use some Arduino Nano
Each Arduino is powered with a 9V battery. In the future I will use Arduino Nano, I am using the VIN pin connected to the positive terminal of the battery, and the negative pin to the GND of the Arduino and not using the jack port.
I want to communicate with both Arduino using the Serial protocol, so I connected the TX and RX pins of the Arduino in a crossway (TX-RX RX-TX). Additionally, I need to connect a common ground so it works, so it needs a connection between the GND of Arduino 1 and the GND of Arduino 2.
As I am connecting the negative terminal to the battery to GND, and then connecting both Arduino with a cable using GND pin, both batteries are electrically connected? Does this represent some kind of danger to the Arduinos? Is there any other way to make these connections?
As I want to do this later on with some arduinos nano, there might be a chance in which I move to some LIPO batteries, there will be any consequences with this as well?
I am brand new to this world of electronics so, I apologize if there is a conceptual mistake.
This means you immediately disabled your ability to use serial.Print() to debug your programs or even display the messages you are sending and receiving. Why did you design your project this way?
When you measure voltage you need a reference point (typically ground). When digital things communicate they do it with a voltage and a reference (typically ground). Putting this in perspective the two digital things are different but they need the same reference point. To accomplish this you connect all of the grounds together. You can actually do a lot more damage by not connecting the grounds. Your computer connects its ground to the Arduino via the USB connections.
Not exactly, I am able to use de the Serial.print() and it works totally fine, the only problem is that I cannot upload changes to the code if those cables are connected.
But anyways, I will change it to other pins using SoftwareSerial Lib