TSYS01 (SPI) accurate temperature sensor with SD card module

Other Hardware Sensors
1

Hey guys! I'm still a novice at arduino so please bear with me. I'm using an Arduino Uno as a the master with two slaves - an accurate temperature sensor (TSYS01) and an SD card module. I connected SCK (D13), MISO (D12), & MOSI(D11) of both modules in parallel. The CS pin of the SD card module is connected to digital pin 4 while the CS pin of the temperature sensor is in digital pin 10. I connected the TSYS01 to the UNO's 3.3V and the SD card module to 5V.

Problem: I'm trying to record temperature and putting the data on an SD card. However, when I open the serial monitor, the temperature sensor reads but the SD card module doesn't seem to write anything to the SD card.

I have the code here:

#include "Tsys01.h"
#include <SD.h> 
#define slaveSelectPin 10 //FOR THE TSYS01 SENSOR
#define powerPin A0
Tsys01* sensor;

const int chipSelect = 4; //FOR THE SD CARD MODULE

void setup() {
Serial.begin(115200);
sensor = new Tsys01(TSYS01_SPI, powerPin,slaveSelectPin);
}

void loop() {
sensor->startAdc();
delay(10);
float temperature = sensor->readTemperature();

Serial.println(temperature);

File dataFile = SD.open("datalog.txt", FILE_WRITE); //writes the data to the sd card
  if (dataFile){
    dataFile.println(temperature,4);
    }
    else {
  }
delay(1000);
}

I read something about using multiple SPI slaves and have done some trial and error but still no success. I tried setting the CS pin of the SD card module to LOW but it's still not writing anything. I removed some SPI related codes since I really don't know what I'm doing and I'm pretty sure that something's lacking with the code.

BTW if you want to know about the TSYS01 sensor you can check out this instructable http://www.instructables.com/id/How-to-Measure-Temperature-Very-Accurately-With-an/