CODEWITHSUNDEEP
arduinoraspberry-piserial-portsodaq-mbili
Thomas Devriese
Thomas Devriese

Reputation: 23

How to read sensor data from Arduino in Raspberry Pi via Serial

for a school project I have to read data from 2 sensors on an Arduino (Sodaq Mbili) board. The sensors I use are TPHv2 (temperature, pressure, humidity) and a Grove Light Sensor. I want to read the temperature, humidity and light intensity. I use the following code for this:

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

void loop() {
    Serial.println(bme.readTemperature());

    Serial.println(bme.readHumidity());

    int sensorValue = analogRead(SENSOR_PIN); 
    Serial.println(sensorValue);

    delay(3000);
}

This gives me the following output every 3 seconds:

21.23
25.65
256

I then connect the Arduino to my Raspberry Pi 2 through USB. I want to get the data in variables so that I can put it in a Json format and send it to an Azure Event Hub. I now have this code in Python on the raspberry (I found this online):

import serial

ser = serial.Serial('/dev/ttyUSB0',9600)
s = [0]

while True:
   s[0] = ser.readline()
   print s

My output then gives, every 3 seconds:

['22.46\r\n']
['37.93\r\n']
['643\r\n']

My question now is, how do I get these 3 values in 3 different variables? I tried to put them in the same array (I want something like this: [22.46,37.93,643] ) but that didn't work.

Does anyone have suggestions? Thanks in advance!

Upvotes: 0

Views: 8707

Answers (1)

Taira
Taira

Reputation: 489

Well, if you don't want to format the code in the arduino like jabujavi said, you could do something like this:

import serial

ser = serial.Serial('/dev/ttyUSB0',9600)
s = []

while True:
    data = ser.readline()   #read data from serial
    if data:                #if there is data, append it to s
        s.append(data)
    if len(s) == 3:         #when s is 3 elements long, (all data has been retrieved)
        print s             #print out s
        s = []              #and then reset s to start over.

Upvotes: 1

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