Connecting an Arduino Nano to a Raspberry Pi using Serial Cable on an a Pi 3B+ or Zero W

Question

I wanted to connect an Arduino Nano to either my Pi 3B+ or my Zero W, preferably my Zero. When I connected my Nano to my Pi Zero and ran a simple script with the Python 3 serial library, it didn't work. I did the same with a 3B+, which didn't work either. I then tried connecting a normal Arduino Uno which worked just fine with both the Pi. I tried looking up the issue, but I didn't find any solutions related to connecting a Nano to any kind of Raspberry Pi. I think it might have something to do with the drivers because my Windows laptop recognizes my Nano.

A shortened version of my Python script:

import serial
from time import sleep

string = ""

sleep(2)
arduinoSerialData = serial.Serial('/dev/ttyACM0', 9600)
sleep(2)

#print statements are for debugging

while(True):
    sleep(1)
    arduinoSerialData.write(b's')
    sleep(1.3)
    string = arduinoSerialData.readline().decode('ascii')
    string = string[0]+string[1]+string[2]+string[3]
    f = open("soil.txt","w+")
    f.write(string)
    f.close
    print(string)

I'm using a standard Arduino Uno and Nano with the given serial cable.

Note: I'm using the "Arduino IDE Linux ARM 32 bit" on my Pi to code the Arduino. It recognizes and works with my Uno but not with my Nano, which led me to believe it was a driver issue. 

Answer 1

The "the given serial cable" is a bog standard miniUSB to USB-A cable. This information belongs in your Question - as does ALL technical detail.

The reference to "Serial Cable" is misleading the cable is USB; the serial interface is on the Arduino - no additional serial interface is needed. (It is technically possible to connect the Pi serial pins to Arduino serial, but far from straightforward, and not necessary).

Similarly the reference to "the GPIO of the Pi Zero" in your Comments is misleading - NO GPIO is involved.

It is unclear what you have connected to what, as the Pi Zero does NOT have a USB-A port (unlike the Pi 3B+) and requires an adapter.

Note the current version is ARDUINO 1.8.13 (some early versions did not support all Arduino models). All Arduino IDE versions have a serial terminal function.

Many Arduino clones DO NOT have the standard USB chips and substitute cheap clones, which are unreliable, and the manufacturer of the official chips has included code to prevent these working with their drivers.

I suggest you first ask on the https://arduino.stackexchange.com/ site to clarify the Arduino issues, then if you still have problems ask a new Question.