A dedicated logger with lots of flexibility, the Paparazzi TWOGA-LOGGA.
The logger is connected between the autopilot and the modem. It stores all telemetry on a micro SD card when power is connected. At the end of the flight a button is pressed just before disconnecting the main battery to stop logging (other ways of stopping are not yet done, e.g. by telemetry message from the GCS or a battery buffered voltage-drop detection). When logging is stopped and the USB is connected the logger acts as USB mass storage device and the micro SD card content can be read with any PC supporting FAT file system. The telemetry data is converted to the standard .data and .log file with a Paparazzi tool. Logging can be started again through a long press of the button if USB was not connected.
We decided to use the well known LPC2148 to do the logging. That allows to use the Paparazzi configuration/tool chain and have a standard USB connection for read out with any PC. All designs have a STOP button. It has to be pressed to close the file and be able to read the data! The USB should be connected after the logger is stopped to prevent going into download mode when re-powered.
LED2 on: logging enabled, press button to stop LED3 flashing: writing message to SD LED2 flashing: logging stopped, connect USB to read out data or press button long to restart logging LED1 on: USB mass storage enabled
It might seem strange that to compile the software to let the Logger hardware work is in the Airframe cnfiguration directory, but that's the way it is. Just use
How to connect the deice and get the data. Description is lacking so please add it here
A real life example and how to use it