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| Title:TempTale Direct Teardown | ||
| Author:rsaxvc | ||
| CreatedDateTime:2017-04-05T22:10:52 | ||
| ModifiedDateTime:2017-04-05T22:10:52 | ||
| Tag:STM32 | ||
| Tag:ARM | ||
| Tag:flash | ||
| Tag:Teardown | ||
| --- | ||
| <h2>A Handy Shipping Watchdog</h2> | ||
| <p> | ||
| Ever wonder if your kobe beef shipped quickly enough? If your | ||
| suspicous neighbor popped the lid on your coolerful of science | ||
| experiment? Some other, simple, zany reason? TempTale makes a line | ||
| of very handy environmental monitors. Drop one in when a sensitive | ||
| shipment is packed, and the receipient can quickly verify that | ||
| the package temperature was maintained through the shipment | ||
| by opening an automatically generated PDF file on the device. | ||
| The device appears as a USB mass storage device with a single PDF | ||
| file onboard. | ||
| </p> | ||
|
|
||
| <h2>But, how does it work?</h2> | ||
| <p> | ||
| Album link:<br/> | ||
| <a data-flickr-embed="true" href="https://www.flickr.com/photos/40925843@N03/albums/72157678556173453" title="TempTaleDirect"><img src="https://c1.staticflickr.com/4/3771/33284635230_b9c74882cb.jpg" width="375" height="500" alt="TempTaleDirect"></a> | ||
| </p><p> | ||
| Internally, it consists of an STM32 ARM microcontroller, | ||
| external serial flash, a coin cell battery with solder | ||
| terminals, some buttons, a high-speed and low-speed | ||
| oscillator, and a bare LCD panel. | ||
| </p><p> | ||
| The bare LCD is neat, as the static discharge on my fingers | ||
| caused a shimmer of pixels when I first touched it. Also, pay | ||
| attention to the front edge below: The glass has metal contacts | ||
| that then touch thin metal sheets embedded in the thick white-faced | ||
| foam strip at the front. Contact is held in by the case and pcb. | ||
| </p><p> | ||
| <a data-flickr-embed="true" href="https://www.flickr.com/photos/40925843@N03/32855532543/in/album-72157678556173453/" title="TempTale direct teardown"><img src="https://c1.staticflickr.com/4/3666/32855532543_34ffea30da.jpg" width="500" height="375" alt="TempTale direct teardown"></a> | ||
| </p><p> | ||
| Software-wise, only a few components are needed | ||
| for something like this. | ||
| <a href="http://www.keil.com/download/docs/362.asp"> | ||
| A USB mass-storage driver</a>, | ||
| <a href="http://www.st.com/content/ccc/resource/technical/document/user_manual/61/79/2b/96/c8/b4/48/19/DM00105259.pdf/files/DM00105259.pdf/jcr:content/translations/en.DM00105259.pdf"> | ||
| a filesystem driver</a>, | ||
| <a href="/~https://github.com/libharu/libharu/"> | ||
| a PDF writer</a>, | ||
| and some custom logic to wake up the CPU from a | ||
| low-power event, likely the RTC alarm, | ||
| read the temperature, and store it to a | ||
| circular buffer. Just before USB enumeration, | ||
| write the circular buffer into a PDF file. Possible | ||
| example components are linked above. | ||
| </p><p> | ||
| These are really handy little devices, I hope they | ||
| become more widely deployed in the future for shipment | ||
| validation. Sensitech even makes models with GPS and | ||
| accelerometers as well. | ||
| </p> |