Logging with the Mooshimeter

The Mooshimeter can be left unattended and will write samples to a microSD card for several months. The Mooshimeter ships without a microSD card installed.

Quick Start:

  1. Format a microSD card <=32GB with a FAT filesystem
  2. Remove the back of the Mooshimeter and install the SD card
  3. Replace the back of the Mooshimeter
  4. Connect to the meter from the iOS or Android app
  5. Configure the meter for the measurement you’d like to take (voltage AC/DC, range, etc).
    1. NOTE: The meter will not autorange in logging mode.  Be sure to set the meter to the range you expect to capture.
  6. Optional: Press the settings icon in the top right of the screen to set the logging interval (time between log samples)
  7. In the bottom left of the metering screen, tap the logging button to turn logging on or off
    • If the meter can not initialize the SD card, the error message will be displayed here and the button will be disabled
  8. Disconnect the app from the meter
  9. The meter will take a sample and write a line to the log file every X seconds, where X is the logging interval.  You will see the LED chirp every time a sample is written
    • In firmware versions >144xxxx, the chirp is 3 quick blinks
    • In firmware versions <144xxxx, the chirp depends on the sample settings

MicroSD card requirements:

  • SD or SDHC (not SDXC)
    • This covers almost all cards up to  32GB
  • Formatted with FAT filesystem

MicroSD card insertion and retrieval:

The Mooshimeter’s MicroSD card slot is on the side next to the reset button.  The keen observer will note that there’s a slot in the case which would give access to the microSD slot without opening the case, but that it has been blocked by a fin.  This is not a defect, it’s the result of product safety testing.  You can read about that here.

To insert or retrieve the MicroSD card, you will need to open the back of the Mooshimeter and push the microSD card in until you hear and feel a click.  Then re-install the back of the meter.


Log Settings

The logging settings are controlled through the Mooshimeter app for iOS or Android.  All measurements settings (input selection, range selection) are controlled through the metering screen.

The logging interval (how often a sample is recorded) is controlled through the meter settings accessed by touching the settings icon in the top right of the metering screen.

If the SD card is properly installed, the bottom left button will allow you to toggle logging off or on.  If the SD card can not be initialized, the button will display an error message.

Log Format

The logs are stored as comma separated value (CSV) files.  There are 3 types of entry:

  1. Log Header: Firmware version and PCB version
  2. Log Settings: Measurement settings including inputs and ranges
  3. Log Entry: A single line of timestamped data
    1. Timestamps are Epoch time, which is seconds since 1970.  You can convert these in to Excel dates with the instructions here.