Simple and cheap temperature logger: New update coming

I’m working on a new revision of the temperature logger: new PCB and new firmware. It’s easier to solder, as the resistors/caps are now 0603 instead of 0402 and the PIC package is now a SSOP28 (instead of QFN).
The sleep current is smaller than 10uA and below 1mA when measuring the temperature (plus a few mA every 20-or-so logs, when writing to EEPROM).

The EEPROM is a SST25WF080 (still 1,8V 8Mb), as the previous Atmel memory is not available any more.

Some 3D renderings of the PCB:

Simple and cheap temperature logger 2.1

The USB connector is a Multicomp MC32604, cheaper than the previous MCKUSBX-SMT2AP1S-W30. (I couldn’t find a suitable 3D model for the PCB rendering)

The ISCP connector for programming the firmware  is SMT but fits the Microchip’s ICD header:

The new firmware has functions for the new EEPROM, a low battery indication, more robust logging and USB update capabilities. Plus a lot of bugfixes and optimizations.

Now, to complete the firmware, I have to build at least one logger, which means ordering the PCB and the components. That’s why I added a “donate” button to this blog (on the top right side of the page, just under the title), especially I don’t earn any money with this blog and content is free (and will stay free, of course).

If my work helped you, if you find it interesting, if you want more articles and more projects, dropping a few coins will motivate me and help me to materialize all the projects waiting in my head. 🙂

Stay tuned for more!



4 thoughts on “Simple and cheap temperature logger: New update coming

  1. Nice to see the change to SSOP28 (more hack friendly :P). Maybe one day you can crowdfund some of the dataloggers (for those who doesn’t have the time, skill or knowledge of ordering pcbs and rest of components 🙂

  2. Thanks!
    I realised I have to get rid of the QFN if I want to be able to make more than a few units myself.
    I’ve been thinking of selling the loggers for quite some time now, but it still have to “mature” the project in my head. For now, I see more cons than pros for this. It’s a great idea, but can turn very quick into nightmare if one isn’t well prepared. So I’ll keep on thinking for now.. 😉

  3. Very interesting reading your detailled progress on this project, especially as the commercially available USB temperature loggers seem to need proprietary software, I look forward to seeing more on this, or perhaps even a version available to buy and solder one day.

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