pinMode(A0, INPUT);
pinMode(A1, INPUT);
pinMode(A2, INPUT);
pinMode(A3, INPUT);
Setting the mode of the digital pins that share space with the analog pins is useless, when you are using the pins as analog pins.
for (;millis() < startTime + 5000UL;)
Why are you abusing a for statement this way? Use a while statement!
Use subtraction involving time, NOT addition.
sprintf(tuf1,"high ");
It's silly to us a sledgehammer to push in thumbtacks. Use strcpy().
It's especially silly to do that, when the print() function can take a string literal, which is all that you are copying to the array.
PT1A = analogRead(A0); // Reads data from analog pin A0
PTT1 = analogRead(A1); // Reads data from analog pin A1
PT1B = analogRead(A2); // Reads data from analog pin A2
PT1C = analogRead(A3); // Reads data from analog pin A3
Are you sure about that? Useless comments should be deleted.
Reading from two different analog pins like that, in succession, often results in incorrect readings from the second pin. Better to read from a pin, discard the value, and read again, when switching pins.
The SD card reader/writer is an SPI device. Do you know what pins SPI devices use, on your Arduino? Do you know that you can't use those pins for other purposes at the same time?