Multiple HC-SR04 sensors, first line only prints a few of them

Projects Programming
1

Hello, I am using an arduino to connect 6 hc-sr04 ultrasonic sensors and then send the output over serial to a rapsberry pi. The pi reads the arduino using serial with python. My issue is that the first line will always be less than 6 sensors but after that all 6 sensors output their distances. How would I fix this on the arduino side so that the first line will output all 6 sensors data?

The output looks like this:
0 2 4 (only 3 of the sensors)
0 2 4 5 6 8 (all 6)
1 5 22 10 12 14 (all 6)

Here is my arduino code using the NewPing library:

#include <NewPing.h>
#define SONAR_NUM 6    // Number of sensors.
#define MAX_DISTANCE 500 // Maximum distance (in cm) to ping.


NewPing sonar[SONAR_NUM] = {   
 NewPing(12, 13, MAX_DISTANCE), // Each sensor's trigger pin, echo pin, and max distance to ping. 
 NewPing(10, 11, MAX_DISTANCE), 
 NewPing(8, 9, MAX_DISTANCE),
 NewPing(6, 7, MAX_DISTANCE),
 NewPing(4, 5, MAX_DISTANCE),
 NewPing(2, 3, MAX_DISTANCE)
};

void setup() {
  Serial.begin(115200); 

}

void loop() { 
  for (uint8_t i = 0; i < SONAR_NUM; i++) { 
    delay(10); 
    Serial.print(" "); 
    Serial.print(sonar[i].ping_in());
   
   
  }
  Serial.println();
}

Here is the python code:

import serial
ser=serial.Serial('/dev/ttyACM0',115200)

while True:
    read_serial=ser.readline()
    val= read_serial.decode()
    val =val.strip()
    print (val)
2

You don't have anything to indicate the start of a line so the Python script just starts reading in the middle of a line. Change the Python to throw out characters until it reads an newline before reading full lines.