Teensy 3.0 based accelerometer datalogger

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.

Looks good.

UnaClocker said:

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.

Click to expand...

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

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.

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