Problem sending analog read values over serial

Question

Ok I apologize as I have edited this quite a bit, but I have narrowed down the problem a bit more. For some reason I can't transfer values from my arduino analog pins??

I am trying to send values from my arduino to raspberry pi over serial (USB cable).

Here is very simple code:

int someVal = 0;
int inputPinA = A0;
int pin = 0;

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

void loop() {
someVal++;
Serial.println(someVal);
delay(100);
pin = analogRead(inputPinA);
Serial.println(pin);
}

When my arduino is plugged into my windows PC, running the arduino IDE, this prints exactly as expected. When my arduino is plugged into my raspberry pi, someval is printed normal, but pin is just 0 repeating... I tried changing int pin = 1; at the beginning to see if it would print 1 instead of 0, but nothing. I also tried Serial.println(String(pin)); which still printed 0.... what is going on here, I am stumped.

Raspberry pi code:

import serial 

ser = serial.Serial('/dev/ttyACM0', 9600,8,'N',1,timeout=None)
ser_bytes = 0
decoded_bytes = 0


while True:
    ser_bytes = ser.readline()
    recoatVal = str(ser_bytes[0:len(ser_bytes)-2].decode("utf-8"))
    print(recoatVal)

I also simplified my python code to:

import serial 

ser = serial.Serial('/dev/ttyACM0', 9600,8,'N',1,timeout=None)
ser_bytes = 0

while True:
    ser_bytes = ser.readline()
    print(ser_bytes)

Which just returns(prints):

b '1\r\n' <----someVal

b '0\r\n'<----pin

Also, some people were asking for what the arduino outputs:

1
245
2
556
3
433
4
545
...and so on

Answer 1

MattG,

analogRead a returns a float.. and the print() was probably getting confused too.

Leave out the int inputPinA = A0; because you only need to put A0 in the AnalogRead.

Make int pin = 0; a float, or better use float pin_value = 0.0; for clarity

Then the stuff in your loop becomes:

pin_value = analogRead(A0); Serial.println(pin_value);

Dave