Go Down

Topic: Problems with tmp100 i2c temp sensor (Read 4 times) previous topic - next topic


Hello folks,

I'm trying to get tmp100 working with arduino fio. Here is the code
#define address 0x94
//address of the temperature sensor

#define delayC 1000
//delay count in ms

#define baudrate 9600
//baudrate for communication

#include <Wire.h>

void setup()

void loop()
  Serial.print("temperature in Celsius: ");
  //let's signal we're about to do something

  int temperature;
  //temperature in a byte

  //start the transmission


  Wire.requestFrom(address, 1);
  if (Wire.available()) {
    temperature = Wire.receive();
  } else {

  //end the transmission


When i run this code, i get "Temperature in celsius: ----" on serial monitor. I guess the device tmp100 is not giving any data to arduino over i2c. I checked address of tmp100 again and temperature register too. Both look fine. I don't understand what the problem is?
Please help!


Any chance you could post a link to the data sheet -- preferably from the manufacturers site? The one that shows the registers and recommended code is helpful. Who made it and what is the full part number.

Did you look for a library or working program for that device??
Just another Hacker


Here's the link to manufacturers datasheet:

The register is 0x00.

Thank you.


have you checked the forum yet ? - http://arduino.cc/forum/index.php/topic,10955.0.html

Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)


Thanks Rob. But i had checked that link already. I have tried some other variations in program also. Few libraries like I2Cmaster etc too!
Now i guess..the problem is in hardware, not the code. I have redesigned the tmp100 board. I'll get it manufactured in couple of days time and try out everything on it again.
Fingers crossed!



Problem is with your code.  You need a Wire.endTransmission after your Wire.send and you need to delete the Wire.endTransmission at the end of the sketch.
I2C GPS Shield

Checkout my Open Source GPS Tracker on Kickstarter


I have found an article about Arduino + TMP100 temperature sensor with Nokia 3310 LCD display here: http://avr.gamfrobotics.hu/?p=141

Go Up

Quick Reply

With Quick-Reply you can write a post when viewing a topic without loading a new page. You can still use bulletin board code and smileys as you would in a normal post.

Warning: this topic has not been posted in for at least 120 days.
Unless you're sure you want to reply, please consider starting a new topic.

Note: this post will not display until it's been approved by a moderator.

shortcuts: alt+s submit/post or alt+p preview