07 – shitty TMP11x breakout boards

A project log for micropower micrologger [mPmL]

A set-and-forget I2C/digital datalogger. Size: 25.3x 18x 10mm incl. battery. Runtime: > 1year

JanJan 08/20/2018 at 20:382 Comments

As I need to try and connect up to four TMP112 sensors to my logger, I decided to make some breakout boards for them. Individual board will be around 6.5x3.5mm.

Address can be changed to one of 4 hex-values by a multi-solder bridge. I did not do fancy panelizing, instead I just chose 0.8mm board and added silkscreen lines where I need to cut the boards with a Dremel or knife:

[+/-/C/D] are the I2C connections, [1/2/3/4] is the address select solder bridge (connect one of them to the longer middle pad) and on the other side is the SOT563 pad with longer pads for easier hand soldering. I'll use a hot air station anyway.
There's space around the lines so I can use up to 1mm cutting disks without damaging the traces.


Edward Mallon wrote 02/25/2019 at 17:29 point

For the trouble of making a separate breakout, you might be better off putting a crystal on your main board for the system clock.  I've been using vanilla Pro Mini boards to measure temperature to 0.0025°C or better using only the watchdog timer inside the mcu:

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Jan wrote 02/25/2019 at 17:44 point

Hi Edward and thanks for your comment!
The breakouts were just a test to connect three external sensors to my logger.
I want all three versions to use the same sensors without needing to calibrate it for each board.

At the moment I am standardizing my loggers to 2 or three versions of which each one has a special use-case.

The smallest one will be 18x13x6mm including battery with a runtime of 2 years logging one temperature every 15 minutes.

The beekeeping-season starts soon, so there is lots of new stuff coming!

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