TMP103 I2C temperature sensor test

Posted byIan 1 Comment on TMP103 I2C temperature sensor test

TI’s TMP103 is a temperature sensor with 1 degree accuracy from -10 to +100 degrees Celsius. The two-wire I2C interface has some special sauce so you can address them all at once, instead of repeating commands to each. Today we’ll take a quick look at the evaluation module for this chip. You can win this or the TMP006 infrared temperature sensor later day, just leave a comment on the giveaway post (comments on this post will not be considered).

The TMP103 evaluation board has 8 tiny temperature sensors. It connects to the same evaluation kit USB module as the TMP006 we reviewed yesterday. This module has data and power pins brought to convenient test points/solderable vias, it would have been nice to do that on the TMP006 too.

TI evaluation kits come with a simple demo application. This time we didn’t need to restart after the install because whatever framework the app uses is already available. Be sure to remove the demo when you’re done, it adds a constantly running webserver program to your computer that could be a security risk.

The test application interfaces with the evaluation board from the USB module. It shows the current reading from each sensor, and gives direct access to read/write the chip registers.

The TMP103 is a fairly slow sensor. We put a bag of ice over the A and B sensors and started the test app. After 22 seconds the temperature had only dropped a few degrees, as seen in the graph above.

If you can afford $50 to check out a new part, these eval kits are great. For TI, they’re probably a necessary evil to get developers to check out super-tiny surface mount parts. The TMP103 doesn’t have a lot of appeal to us because there’s so many temperature sensors out there with versions in more friendly packages. The TMP006 infrared temperature sensor is very cool though, and we’re going to make some cheap breakout boards for it.

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1 Comment

  1. The license on the demo code starts out ok:

    Unless otherwise stated, the Program written and copyrighted by Texas Instruments is distributed as “freeware”. You may, only under TI’s copyright in the Program, use and modify the Program without any charge or restriction. You may distribute to third parties, provided that you transfer a copy of this license to the third party and the third party agrees to these terms by its first use of the Program. You must reproduce the copyright notice and any other legend of ownership on each copy or partial copy, of the Program.

    But then it degrades into:

    You acknowledge and agree that the Program contains copyrighted material, trade secrets and other TI proprietary information and is protected by copyright laws, international copyright treaties, and trade secret laws, as well as other intellectual property laws. To protect TI’s rights in the Program, you agree not to decompile, reverse engineer, disassemble or otherwise translate any object code versions of the Program to a human-readable form. You agree that in no event will you alter, remove or destroy any copyright notice included in the Program. TI reserves all rights not specifically granted under this license. Except as specifically provided herein, nothing in this agreement shall be construed as conferring by implication, estoppel, or otherwise, upon you, any license or other right under any TI patents, copyrights or trade secrets.

    And then dies with a whimper:

    You may not use the Program in non-TI devices.

    TI is pretty good with open source, but this is a weak spot. This is example code should be public domain IMHO…

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