SDLogger SPI Direct
Introduction
The direct SPI SD Logger is originally designed to be used with the Lisa/S, but should also be compatible with other supported autopilots. It connects directly to the SPI bus of the autopilot and communicates using the SDCards SPI interface. This method is slower than when using it in SD mode, but the speed is sufficient to log IMU data at 512 Hz.
Hardware
Installation
The SD Card needs to be connected to the SPI bus of the autopilot. The pinout for an SD Card is shown in the figure.
- VSS = Ground
- VDD = 3.3V
KroozSD
The KroozSD(BRE) board has a built in SD card slot connected over SPI bus to the controller. So all you need is to add the following:
<load name="logger_sd_spi_direct.xml"> <configure name="SDLOGGER_DIRECT_SPI" value="SPI1"/> <configure name="SDLOGGER_DIRECT_SPI_SLAVE" value="SPI_SLAVE0"/> <configure name="SDLOGGER_DIRECT_CONTROL_SWITCH" value="RADIO_CAM"/> <configure name="LOGGER_LED" value="3"/> </load>
to the modules section of your airframe file, choose the mx-16.xml as radio setup and insert the SD card into the board. In this case the logging should be started/stopped over the 8th channel of your radio control (set the proper switch on the 8th channel of your sender).
Lisa/SD
A SuperbitRF-sized PCB connects the SD card to the Lisa/S. Additionally, this PCB has pads to connect a Deltang R31d RC receiver and a molex connector for general purpose.
Software
Retrieving the data
A logger is of no use if one can not easily retrieve the logged data. To make this a simple reality there is an app for that.
- Connect the FTDI cable to the computer and autopilot.
- Plug the battery or external power to the autopilot.
- Start the logger download tool.
The tool is found in this directory : sw/logalizer
So a simple
cd ~/paparazzi/sw/logalizer/ && ./sdlogger_download -a <AC_ID> -p /dev/ttyACM1 -b 115200
where <AC_ID> is your aircraft ID, would start the process of reteiving the data from the SD card to your local machine, ready for you to use.