General > General Technical Chat
Single-use temperature data loggers?
justanothercanuck:
So work occasionally throws out these temperature data loggers that according to the specs are for single use only... They use 2 different models, but here's the info on one of them...
http://www.sensitech.com/products/tt4usbfood
http://www.sensitech.com/assets/datasheets/fdtt4usb909.pdf
I got bored and cracked two of them open and noticed that it's just a battery with an ATMEGA, some support circuitry and a zebra strip glass LCD.
If that's all that's in them, I wonder what it would take to hack them to being re-usable, and possibly as a general use thermometer (since the range appears to be -30 to 70c)... My guess is they're either doing the single-use stuff by code, or battery voltage.
Sorry, no pictures of the boards at the moment, if I remember, I'll crack them open again and take a few.
Ian.M:
Due to the security requirements of their application, I suspect you'd have to reverse engineer the hardware and reflash them with your own code, as if they could be reset for reuse by any simple method it might be possible to compromise their log and cover up a storage/shipping temperature control failure.
Yansi:
awwww I have a bunch of those gizmos in my lab too. There's not much to reverse engineer inside. There's a crappy old ARM from Atmel, big 8bit cheapass MCU for handling the display, some ultra-hermeticaly sealed zncl non-rechargable battery and thats mostly it. The temperature is measured by a blobby NTC.
My friend even googled out matching PC firmware for these units, but we hadn't been successful runing it, because it required some license number we weren't able to find or hack around. But I think there is nothing interesting, only if you want some basic parts and two crappy old MCUs. :)
Here's a hi-res photo of the similar units I have. (Hope the eevblog will upload it).
//It won't. So only a small preview and here's link for the hi-res: http://n34.imgup.net/IMG_36822527.JPG
Oh, and I forgot to mention, it is not probably soldered with the patented european ROHS solder crap, it seems it is nice lead solder on the board.
amyk:
Free is free... USB MCU with display and temperature sensor isn't so bad.
Yansi:
It IS bad actually. Opening the heck-of-a-solid hermetically sealed glued or welded plastic enclosure plus desoldering the old crusty MCU plus one stupid NTC is simply not worth it.
You can have modern MCU with USB for just about one or two bucks.
Navigation
[0] Message Index
[#] Next page
Go to full version