It would be great if SparkFun would supply example code in PicAxe BASIC as well as the ATmega and ARDUINO

Will Sparkfun be making more of these? I like the tiny size versus the SEN-11931 breakout.

Hey Guys!

Am a newbie in PIC programming. I recently purchase this tmp102 breakout board for my school project. Am trying to read the temperature register with PIC16F877A using CCS Compiler. I connect the SDA and SCL to the SDA and SCL pins of the PIC respectively and ADD0 to ground. The tmp102 is powered with 3.3vcc. Everything went weird as what am getting is 255(0xFF) and 255(0xFF) for the MSB and LSB respectively. This might not be the appropriate place to post this challenge, but has any one done something related to this or can link me to other resources?

Here is the code am using in CCS C

// tmp102 code
#include  
#FUSES NOWDT                     
#FUSES HS                        
#FUSES NOBROWNOUT                
#FUSES NOLVP, PUT 

#use delay(clock=20000000)
#use i2c(Master, sda=PIN_C4,scl=PIN_C3) // Configure Device as Master
#use rs232(baud=4800,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,stream=UART, ERRORS)

#define TMP_RD       0x72
#define TEMP_REG    0x00

void main()
{

delay_ms(2000);         
 fprintf(UART,"TMP102 Example \r\n");
 fprintf(UART,"Reading Started...\r\n");
 delay_ms(500);
 while (1)
   {
      unsigned int8 msb, lsb;

      i2c_start();   
      i2c_write(TMP_RD);      // Read from this I2C address, R/*W Set
      delay_ms(50);
      i2c_write(TEMP_REG);       //Set pointer regster to temperature register  
      msb= i2c_read(1);            //Read the MSB data
      lsb = i2c_read(0);            //Read the LSB data
      i2c_Stop();

      printf(" %u ", msb); // check
      printf(" %u ", lsb);    // check

      delay_ms(3000); 
   }
}

Thanks

I did a little project to get back into electronics using this sensor and your Electric Imp breakout last weekend. This blog may help someone that has the same idea :) http://techgurka.blogspot.com/2013/04/quick-temperature-graph-using-electric.html

This sensor is incredibly stable. I have used and abused it while experimenting (dropping it, etc), it is still going strong. Being digital, it is not necessary to take an average of 5 or so readings as is commonly done with analog sensors. IMO the easiest to use as far as code goes (maybe tie with the TMP36 or a thermistor). I have an Arduino mounted (in a box) on the outside of a snake cage, connected to this sensor placed in a box inside the cage. I use the Arduino to control heating (Arduino output to an NPN transistor circuit to a zero-volt-turnon SSR and LED for status.) Works nicely.

Hey Guys,

I just want to give you a link to some example code written in C that I used to communicate with the TMP102 from my Raspberry Pi through its I2C ports - http://bit.ly/X8xZGi Hope it's helpful!

How do I get this board to work with a Sparkfun Pro Mini (5V)?

It works just fine on an Uno. I'm using a voltage divider to reduce current on V+ to 3.3v. I'm guessing that it has to do something with needing to add pullup resistors on A4 and A5 or possibly converting the current to 5v on A4 and A5, but can't seem to find a wiring diagram on how to do that.

I get this error when I try to compile the program using AVR studio for the Atmega328. In the file ic2.h I get this:

error: 'F_CPU' uncleared (First used in this function)

Code:

    //calculate bitrate division    
bitrate_div = ((F_CPU/40001)/bitrateKHz);
if(bitrate_div >= 16)
bitrate_div = (bitrate_div-16)/2;
outb(TWBR, bitrate_div);

Any help guys?

Does this product have eagle file? or this is not OSHW.

I'm using the following code and it reads 31.86 F and -0.06 C It's nearly 75 F in here. And it appears to be stuck on this numbers? Any ideas ? Thanks in advance, Rick

//Arduino 1.0+ Only //Arduino 1.0+ Only

////////////////////////////////////////////////////////////////// //©2011 bildr //Released under the MIT License - Please reuse change and share //Simple code for the TMP102, simply prints temperature via serial //////////////////////////////////////////////////////////////////

include

int tmp102Address = 0x48;

void setup(){ Serial.begin(9600); Wire.begin(); }

void loop(){

float celsius = getTemperature(); Serial.print("Celsius: "); Serial.println(celsius);

float fahrenheit = (1.8 * celsius) + 32; Serial.print("Fahrenheit: "); Serial.println(fahrenheit);

delay(200); //just here to slow down the output. You can remove this }

float getTemperature(){ Wire.requestFrom(tmp102Address,2);

byte MSB = Wire.read(); byte LSB = Wire.read();

//it's a 12bit int, using two's compliment for negative int TemperatureSum = ((MSB > 4;

float celsius = TemperatureSum*0.0625; return celsius; }

For anyone using a Raspberry Pi (or any other Linux device) there is support built into the kernel for these sensors using lm-sensors (so you don't have to write your own drivers). Make sure the temperature sensors (LM75 I think) are compiled into your kernel as well as i2c-dev, then, as root:

echo tmp102 0x48 > /sys/class/i2c-adapter/i2c-0/new_device

Replace 0x48 with your address and tmp102 with whatever chip you have. I don't have the 102, but have a bunch of TMP100's I sampled a while back that work perfectly with this setup (using 'tmp100' instead of 'tmp102').

Here's a perl script I made for use on the Raspberry Pi using the Adafruit Occidentalis OS.

Run this script as root or sudo to output the current temperature in Celsius and Fahrenheit:

#!/usr/bin/perl

#Grab the data from the device (Addr0 pin tied to ground gets 0x48 address)
$rawhex = `i2cget -y 0 0x48 0x00 w`;

#Switch the position of the two bytes and convert to integer
$decimal = oct("0x" . substr($rawhex,4,2) . substr($rawhex,2,2));

#Shift right four bits (12 bit mode)
$decimal = $decimal >> 4;

$celsius = $decimal * 0.0625;
$f = (9.0/5.0) * $celsius + 32;

#Profit!
print "C: $celsius, F: $f\n";

I'm having trouble getting this to work with an Arduino. I have hooked it up to A4 and A5, and I have it on the 3.3V power supply with the reference pin tied to ground. When I use the Bildr code to try to test it, I'm only ever reading values of 0 from the device. that is, I will get a temperature reading of about 0.0625 degrees celcius no matter what. This is my first time using I2C, so I might have made some stupid mistake, or I could have a bad chip, who knows. Any help anyone can give would be awesome. Thanks!

Has anyone used this thing with an MSP430??

I'm trying to incorporate this sensor for a project. I'm using an MSP430 F169 on an Olimex development board. I already have an LCD working and displaying calculations based on the closures of two reed switches.

I'm using Code Composer Studio V5, and I haven't been able to read anything from the sensor. I have the I2C interface set up, and have been messing with all kinds of things, from addressing to timing, but I, for the life of me, cannot read a temperature.

Any help would be greatly appreciated!!

Thanks, Mike

If this temperature sensor outputs a digital signal why is it connected to the analog inputs of the Arduino?

You guys might want to consider adding a pullup or pulldown resistor in the next revision. Without a connection on ADD0, the sensor stops transmitting valid data whenever there is electrical interference (a finger on the connections, for example). If anyone has this problem, tie ADD0 to ground (address 72) or V+ (address 73). Also, on the arduino, 3.3V is enough to register high on the I2C bus, so no logic converter is required.

I composed a blog on using the Speakjet with a PICAXE-18M2 and an I2C temp sensor TMP102 in PICAXE Basic code for another programming example. Less than 40 lines of code made a system that compares the last temperature reading to the current one, and speaks "hotter" or "colder" if it changes a degree or more. [http://dinsmorerobotlab.blogspot.com/2011/09/hottercolder-talking-temp-sensor.html]

Can these be cascaded on one bus? That is, can I connect 4 of these on a single bus and connect them to a netduino? I can't remember if the i2c lets you do that or not...

Can the TMP102 be used with DEO-nano from terasic? Is there example assembly code for the TMP102? Thanks.

Argh! :) Been banging my head against this device for months now and i can't get it to work in LabVIEW with an Arduino for the life of me. If anybody has this TMP-102 working in LabVIEW can you PLEASE post a link showing how you did it?

Board dimensions: 1cm by 1.3cm
The chip is in the exact middle of the board.

BTW, here is the code in StickOS (on PIC32, ColdFire, etc.) to print the temperature in degrees C:

list
10 dim r as byte, t[2] as byte
20 let r = 0
30 i2c start 0x48
40 i2c write r
50 i2c read t
60 i2c stop
70 print t[0]
end
run
25
_
See: http://www.cpustick.com/index.htm

Though it is a trivial task, I figured that many people new to this sensor would look here for info as I have.
To get an output in degrees F, someone going by the conversion formula might attempt to do ((Counts * 0.0625) * 9/5 + 32), but that will give you an incorrect result.
The proper way is to first shift the °C/count scale to a °F/count scale, and for this step you must leave out the "+ 32" part of the equation. Only after you have multiplied your raw data by the 0.1125°F/count (0.0625°C/count * 9/5) scale factor do you add the 32°.
The correct equation is therefore (counts * 0.1125) + 32.
Trivial, but hopefully will save someone a few minutes of confusion. I used the code from the wiring example posted.

Oh, man... I was just about to buy a couple of these. Any idea when they will be back in stock?

There is a Netduino friendly example here:
http://forums.netduino.com/index.php?/topic/906-sparkfun-tmp102-digital-temperature-sensor/

Why not make a breakout board for the TMP275 instead of this particular chip? Though the low current and large range are appreciated in this case, it's voltage requirements are different than that of the vast majority of micro-controllers out there. It adds just a little more unneeded cost and complexity to circuit design. I can buy the TMP275 in a breakout board elsewhere, but I'd rather just get everything I need here.

Does this work in Standard mode?

Has anyone hooked one of these up to an arduino?

futzle: I contend that connecting A0 to GND (72) or V+ (73) are the only reliable options.
I'm not even convinced of this any more. With A0 wired straight to V+, my TMP102 was responding happily on address 72. Then switched to 73 spontaneously after a few hours.
I'm going to stop fighting it, and wire A0 straight to ground. If I need another temperature sensor on my household I2C bus I'll have to look for a different brand.

tz: So, if I leave the A0 pin unconnected, it acts like it is grounded, i.e the address is 1001000?
I'd say that the absence of an answer in the spec means "then don't do that".
I lost a couple of hours today trying to talk to the TMP102. Figuring that with A0 in line with SDA on the breakout, I'd save having to cut the stripboard between the two pins. The datasheet puts that configuration at address 74. But respond it didn't. Only by accident did I find that it was listening on address 73 all along, as it is supposed to when connected to V+. I contend that connecting A0 to GND (72) or V+ (73) are the only reliable options.

So, if I leave the A0 pin unconnected, it acts like it is grounded, i.e the address is 1001000?
Or is it pulled up or something else? (Hard to tell from the data sheet - it doesn't say it requires a pullup, but then it doesn't say what it does if not connected to anything, only if connected to any pin but ALERT).