NT Data Logging: Difference between revisions
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The NT logger module is connected to the NT bus, as any other NT module. | The NT logger module is connected to the NT bus, as any other NT module. | ||
The micro SD card must be formatted with FAT32. | The micro SD card must be formatted with FAT32. The firmware author uses the Windows tool. Using the [https://www.sdcard.org/downloads/formatter_4/ SD Association formatting tool] didn't yielded any noticeable advantage. | ||
The micro SD card should be of very high speed. Unfortunately, not any card works equally well. Little experience is available so far: | The micro SD card should be of very high speed. Unfortunately, not any card works equally well. Little experience is available so far: | ||
Revision as of 08:37, 29 March 2016
A data logger can be connected to the NT bus, which allows us to record on a micro SD card a substantial amount of data for each cycle of the controller loop. It thus records the data with the maximal possible time resolution. Furthermore, the logger is quite small and can be easily mounted on-board. As a result one can get highly accurate and informative data taken in the real flight condition. This hopefully will allow use to better diagnose any troubles, such as jello or micro vibrations in the video, and find solutions to resolve them.
The data logger option also suggests many other applications. For instance, it can be used to dynamically balance the motors and propellers.
NT Logger Module
The NT logger module is connected to the NT bus, as any other NT module.
The micro SD card must be formatted with FAT32. The firmware author uses the Windows tool. Using the SD Association formatting tool didn't yielded any noticeable advantage.
The micro SD card should be of very high speed. Unfortunately, not any card works equally well. Little experience is available so far:
| micro SD card | experience | reported by |
|---|---|---|
| SanDisk Extreme SDHC 16GB UHS-I Class 10 U3 | very good, data loss just every once in a while | OlliW |
| Kingston 8GB HC class 4 | don't work | OlliW |
| Kingston 32GB HC class 4 | don't work | OlliW |
NTLoggerTool
For analyzing the recorded data, the NTLoggerTool is available, providing tools such as FFT, and others. It also allows us to convert the data into other formats, most notably into .cfl files. The .cfl files are suitable for the program BlackboxExplorer for STorM32, which is a decendant of CleanFlight's powerful BlackboxExplorer. The NTLoggerTool also allows us to record directly the data on the NT bus usiang a USB-TTL adapter, which enables many work-bench tests and procedures.
The NTLoggerTool is steadily advancing with fast pace, and any manual would be quickly outdated. For a discussion it is best to join the STorM32 NT thread at rcgroups.
The NTLoggerTool is open source (GPL3). Anyone is highly welcome to contribute to it.