RS-485 Serial Communication between Raspberry Pi and Arduino Uno

Overview of RS485 Serial Communication Protocol:
RS-485 is an asynchronous serial communication protocol which doesn’t not require clock. It uses a technique called differential signal to transfer binary data from one device to another.

So what is differential signal transfer method?
Differential signal method works by creating a differential voltage by using a positive and negative 5V. It provides a Half-Duplex communication when using two wires and Full-Duplex requires 4 fours wires.

[beastflow]

Thank you just what I was looking for!

[Antipathie]

Heyho, don't we need a Logic Level Converter for the Raspberry Pi in order to protect the Input Pins?

[rishabhgawai]

Does anyone knows how to send data from raspi to aurdino.
it should be modbus rtu communication.
If needed Max 485 module can also be used.

[fabiooliveira]

I am Brazilian and I speak Portuguese, I did the translation by Google translator, so if something is wrong, sorry, but I really liked your project, congratulations.

But I would like to know if it would be possible with this script, just as information was sent from Raspbian (master) to Arduino (slave), if there is a possibility of arduino sending information to raspiberry, for example if instead of the display print the information, this information would be sent to raspiberry.

[priyapriya-nrvp]

hi, ,
why we use arduino, , cant we use modbus, , please reply

[ibrahim-]

how to make raspberry receive data from slave?

[harditakurniawan]

hey dude, can u help me how to send integers from raspi to arduino over usb cable??
my code for raspi :
import serial
usbCom = serial.Serial('/dev/ttyACM0', 9600)
#usbCom.open()
x = '31'
usbCom.write(x)


and this is the code in arduino :
int usbRead = 0;
//String message = "";

void setup(){
Serial.begin(9600);
}

void loop(){
if (Serial.available()){
usbRead = Serial.read() - '0';
Serial.println(usbRead);
}
}


I want to send 31 to arduino but when I check in serial monitor there are 2 numbers (3 and 1) not 31