Logging data to SD card from software serial

Question

I have an Arduino Uno and an Adafruit data logging shield and I have connected a digital pressure sensor that uses serial communication. The sensor requires a character to start transmitting data. I have managed to read the data using this code:

#include <SoftwareSerial.h> 
SoftwareSerial mySerial(8,9); 
int depth;
void setup() {
 Serial.begin(9600);
 mySerial.begin(9600);
 mySerial.print("C");
}
void loop() 
{
 if (mySerial.available()) {
 depth = mySerial.read();
 }
}

This returns the following:

C1000
C1000
C1000

where 1000 is the value.

I have written another code that logs data to the shield and tested with other sensors but I cannot log data from this sensor by modifying the above code and cannot find any relevant examples. If I add something like this it does not return the same value.

logfile.println(depth);

Complete newbie in so any suggestions are welcome.

UPDATE

enter image description here

• VE7JRO: Comments are not for extended discussion; this conversation has been moved to chat.

Answer 1

use the C as the line start indicator. if received char is 'C' then do a file.println(); example with output to Serial

#include <SoftwareSerial.h> 
SoftwareSerial mySerial(8,9); 
void setup() {
 Serial.begin(9600);
 mySerial.begin(9600);
 mySerial.print("C");
}
void loop() {
 if (mySerial.available()) {
 char c = mySerial.read();
 if (c == 'C') {
 Serial.println();
 }
 Serial.write(c);
 }
}

• Nik_ol: But this code does not do anything different than the simple code. My problem is not that I am not reading the data or that I do not see the data printed in the serial monitor. I do receive all the data. The problem comes when I try to log the data. I think the data come in so fast from the serial, but when I add delays everything is messed up.
• Juraj: it prints completely different then the code in Question. did you try it?
• Nik_ol: Yes I tried it. It prints the same with a gap between its measurement. Also it uses a lot more of the dynamic variable. But it prints the same with a gap between each C1000
• Juraj: is it not what you want? every set on a new line?
• Nik_ol: No. I want to log the data to an SD card. When I use this code to log I get one number every second. I have added a screen shot in the original post. I want to get all the 4 numbers in one second and then the new 4 numbers in the next second.