How to read from ATmega328P with Raspberry Pi

[henkoegema]

I have compiled and flashed following program to the atmega328P (connected to a raspberry pi). This program reads a voltage on pin. A0

============================Begin program================================
const int analogInPin = A0;

float sensorValue = 0;

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

void loop() {
sensorValue = analogRead(analogInPin);

Serial.print(¨Voltage Output = ");
Serial.print(sensorValue*5/1023);
Serial.println(" ");

delay(100);

}
===============================End program================================

I only use the command line in the raspberry pi. (no GUI)

When I've flashed the program I get the command prompt back.
Q: How do I read the values of the program in the atmega328p back in my raspberry pi?

[BulldogLowell]

@henkoegema

are they connected via Serial TX/RX?

[henkoegema]

Connected via SPI (MOSI, MISO,.....etc)