I need to work with SD card and TCRT5000 sensor (Reflective Optical Sensor with Transistor Output) and save data from sensor to file. So I select Arduino Uno and added to it a SD card shield(from LC STUDIO) and a TCRT5000 sensor but it isn't working. My circuit and code is here: enter image description here

#include <SPI.h>
#include <SD.h>

const int chipSelect = 10;

void setup() {
  pinMode(chipSelect, OUTPUT);
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
  Serial.println("card initialized.");
  File dataFile = SD.open("test.txt", FILE_WRITE);
  dataFile = SD.open("test.txt", FILE_WRITE);
    Serial.println("Error in creating file.");

void loop() {
  float value = analogRead(A3);
  File dataFile = SD.open("test.txt", FILE_WRITE);
  if (dataFile) {
    Serial.println("Error in opening file.");

When TCRT5000 isn't connected SD card working without any problem. I think it is related to current and supply current. Any idea?

  • 1
    I would like to believe that you made a mistake with +5 and GND from board???
    – Martynas
    Commented Oct 17, 2014 at 10:56
  • 60mA can not do any problem. Maybe you connected it wrong? 90% problems are in wiring :))
    – Martynas
    Commented Oct 17, 2014 at 11:30
  • I checked it again. The circuit isn't wrong. I do it like this and this. If problem is not related to current,it is related to what? Why the SD card work when I remove TCRT5000 from circuit without any change in wiring?
    – Ahmad
    Commented Oct 17, 2014 at 14:03
  • Try disconnecting only D+. That way you know if the problem is with the IR-diode or the phototransistor.
    – Gerben
    Commented Oct 17, 2014 at 17:21
  • 1
    The 5V to the breadboard power rails is 100% not in the right spot. Both the 5V and GND are in the same rail, causing a short. I assume this is just an error in the diagram, like @Martynas said? Commented Dec 5, 2014 at 22:42

1 Answer 1


Did you figure this out yet? If not, you have the +5 volts going to the GND on the breadboard, causing a short.

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