Teensy 3.0 based accelerometer datalogger

[UnaClocker]

This is my latest creation. It's something I've been trying to make for awhile now. First couple tries were with an ATMega328, which I couldn't even get to write to the SDCard. I'm hoping this one works out. The board is 2.1"x.9", uses a Teensy 3, which I'll probably permanently solder to the thing. It's going to read an ADXL345 accelerometer and record the readings to a MicroSD card.
The board is going to run off a LiPo pack, so I used an LT1962 3.3v regulator. It's good for 300ma. I also put a 12mm coin cell on the board to run the RTC, so I can timestamp the datalogs.
I'll keep everyone posted on how it works out.

 

[Constantin]

Looks good.

View attachment 104
This is my latest creation. It's something I've been trying to make for awhile now. First couple tries were with an ATMega328, which I couldn't even get to write to the SDCard. I'm hoping this one works out.

I'm surprised that you couldn't breadboard a solution with a pro mini from sparkfun (328P running at 3.3V and 8MHz), a chronodot, and a SD card writer. Then bake your own board later based on the same components. Using a teesny for this application seems a bit overkill, but who am I to criticize, others have pointed out the same thing about my power monitor.

Best of luck and look forward to hearing how it went. Cheers! Constantin

 

[UnaClocker]

Got the boards, got pins that fit in the really tiny holes that accidentally got put into the Teensy footprint I had created. The voltage regulator works (haven't scoped it yet, to check out how clean it is). The RTC backup battery works. The uSD card works, though the footprint I used was all funky and I had to dig and dig to find one that mostly lined up, after finding out the ones I had don't line up at all. The temp sensor is noisy as hell, so I'm looking into that. And the accellerometer doesn't work, the microcontroller seems to lock up when I try to initialize the i2c bus.. So I need to desolder it and try again, must have gotten some of the crazy tiny pads bridged.

 

[Jp3141]

There's a possible issue with the I2C where you need to add external pull-up resistors -- do you have them ?