So, I know I can find this query's answer on Google, Still I wanna make sure. (I am scared of doing something wrong.)
I have connected by raspberry pi to a power bank (5V - 3A).
My Arduino Uno is getting its power from the dual bridge H motor (5V - 2A).
For them to communicate together, I just have to connect both of their ground with each other. Isn't it? Is anything else to do.
I am following a tutorial to learn, they power bank powered Arduino, R pi and motors (idk some great power bank he has) so it basically means the ground are connected to each other internally right? In my case I can just connect GPIO pin (ground pin of Rpi) to Arduino GND pins, right?
You certainly need to connect their GND pins together to give them a common point of reference, but that alone will not make them able to communicate with each other
For that you need some method of communication such as a serial link, which will need 2 more pins to be connected to allow the transmit pin on one device to send data to the receive pin on the other and vice versa
Other forms of communication are possible, but what data do you wish to pass between them and why ?
I am using Wiring Pi library. So I am going to use digital pins of raspberry to give input to Arduino Uno. I am just sending commands to Arduino Uno digitals pins on basis of some calculations!
Thanks for the help. So, should I connect Rpi GND pin to Ard Uno GND pin?
Yes, connect the GND pins, but there is another consideration when it comes to connecting their digital pins and that is the voltage that they run at
The Arduino Uno runs at 5V and will output 5V digital signals. I believe that the Pi is a 3.3V device. If so, then putting 5V on one of its digital pins may damage it. I know that is not what you are planning to do but be careful
Consider using a voltage shifter between the 2 devices