Accepting multiple inputs from Pi and sending to Arduino and storing all the values in Variables

[Prominent_being]

Hello,
I am trying to communicate between Raspberry Pi and Arduino using serial. I want to send input data from Pi to Arduino and Arduino should store in variables all the values from Pi. I am unable to read and store data in Arduino Variables although my python code is working fine. please help me with it.

Python Code (Working)

import serial
import time

if __name__ == '__main__':

    ser = serial.Serial('/dev/ttyACM0', 9600, timeout=1)
    
    ser.reset_input_buffer()
   
    while True:
        
        pul, csol, sol, de = input("pulse = ") ,input("From Solenoid = "),input("To Solenoid = "),input("delay in minutes = ")
        print(pul,csol,sol,de)
        ser.write(pul.encode('utf-8'),csol.encode('utf-8'),sol.encode('utf-8'),de.encode('utf-8'))        

Arduino Code

int pulse, From_Solenoid, To_Solenoid, Delay;

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

}
void loop() {
  if(Serial.available()>0){
    int pulse = Serial.readStringUntil('\n');
    int From_Solenoid = Serial.readStringUntil('\n');
    int To_Solenoid = Serial.readStringUntil('\n');
    int Delay = Serial.readStringUntil('\n');
    Serial.println(pulse);
    Serial.println(From_Solenoid);
    Serial.println(To_Solenoid);
    Serial.println(Delay); 
}
}

[PaulRB]

@Prominent_being

ser = serial.Serial('/dev/ttyACM0', 9600, timeout=1)

What kind of Arduino is this? How is it connected to the Pi?

[Prominent_being]

It is port number when you connect Arduino to Raspberry Pi

[b707]

In Arduino you wait for newline after each reading:

@Prominent_being

int pulse = Serial.readStringUntil('\n');

I don't know python well, but does this line insert newlines between values?

@Prominent_being

print(pul,csol,sol,de)

[jfjlaros]

You could consider using an RPC library and Python client.

The Arduino code could look like this:

#include <simpleRPC.h>

void solenoid(int pulse, int from, int to, int wait) {
  Serial.println(pulse);
  Serial.println(from);
  Serial.println(to);
  Serial.println(wait);
}

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

void loop() {
  interface(Serial,
    solenoid, F("solenoid: Solenoid stuff. @pulse: Pulse. @from: From. @to: To. @wait: Wait."));
}

and this would be the code on the Raspberry Pi:

from simple_rpc import Interface

interface = Interface('/dev/ttyACM0')

interface.solenoid(1, 2, 3, 4);

Alternatively, you could send delimited text and use a text parser library, e.g.,

#include <textparser.h>

TextParser parser(", ");  // Delimiter is a comma followed by a space.
int pulse, From_Solenoid, To_Solenoid, Delay;

void loop() {
  char line[80];

  // Assume `line` is of the form "1, 2, 3, 4\n".
  Serial.readBytesUntil('\n', line, sizeof(line));
  parser.parseLine(line, pulse, From_Solenoid, To_Solenoid, Delay);
  Serial.println(pulse);
  Serial.println(From_Solenoid);
  Serial.println(To_Solenoid);
  Serial.println(Delay); 
}

And of course you can come up with your own protocol.

[Prominent_being]

thankyou