# SD-card storage If you don't want to store data on the platform, or remote connectivity is not available for you, you can choose to store data on the SD-card. By default, the [Data Board](https://docs.smartcitizen.me/hardware/boards/data-board.md) comes with a 16Gb micro SD-card, which can literally store years of data. Sensor data is stored in [CSV format](#sensor-readings). You will also find other files, which are described below, such as [hardware information](#hardware-information) or other special features, such as [debugging](#debugging), or the possibility to [access SD-card data via USB](#console-access). ## Sensor readings Data is stored on the SD-card in CSV format, with a `comma` separator and `UTF-8` encoding. Each day, a different data file is stored on the onboard SD-card, named `YY-MM-DD.CSV` (for example, `24-05-01.CSV` would contain data from May 1st, 2024). In case the [Data Board](https://docs.smartcitizen.me/hardware/boards/data-board.md) resets, it will generate an additional file for that day, and name it `YY-MM-DD-XX.CSV`, where `XX` are incremental numbers indicating the number of files (for example, `24-05-01-01.CSV` would contain data from May 1st, 2024, alongside with the previously generated file `2024-05-01.CSV`). !!! warning "Many files with additional numbering?" This could be a symptom that the device is having hardware issues, as it may be rebooting more than usual! !!! danger "Breaking change" As of firmware release `0.9.9`, the naming convention changed for these files. Previously, the naming was `YY-MM-DD.XX`, being `XX` the same as above. For convenience, the `.CSV` file extension was kept when `0.9.9` was released. The file format for the sensor readings is as follows:  Below you can find what each row/rows mean, in order: - `Short name`: Short name for the variable captured - `Units`: units in which the measurement was taken - `Description`: Short description for the variable captured - `Sensor ID`: this row is necessary in case you want to upload data to the [Data Platform](https://docs.smartcitizen.me/data/data-platform.md). Do not delete or change this row, becase data may get all mixed up! - `Data rows`: each row follows the same format, being the first column the `timestamp` in `ISO8601` and `UTC` format. Subsequent columns represent data, with `.` representing decimal numbers. Missing data is represented by `null`. ## Hardware information Hardware information is stored in a file called `INFO.TXT`. This file can be used to retrieve firmware information, hardware versions, and some brief debugging information. The same information is available via the [API](https://api.smartcitizen.me/devices) (on `hardware>last_status_message`) and on the [mobile access point](https://docs.smartcitizen.me/hardware/kit/features.md#local-access-point). This file contains the device serial number and the hardware and firmware versions and build dates for both microcontrollers: ``` Hardware Version: 2.1 SAM Hardware ID: SAM version: 0.9.7-5bbe51f SAM build date: 2021-05-25T18:50:42Z ESP MAC address: 8E:CE:4E:D5:62:45 ESP version: 0.9.2-5bbe51f ESP build date: 2021-05-25T18:51:28Z ``` ## Special features ### Console access As of firmware `0.9.9`, you can access data via USB by using the [shell](https://docs.smartcitizen.me/guides/getting-started/using-the-shell.md). The `file` command can become very handy to access to SD-card data, without having to extract the SD-card. ``` SCK > help ... file: SD card file operations: [-ls] [-rm filename] [-less filename] [-allcsv] ``` You can list files by: ``` SCK > file -ls Files found (date time size name): 2024-01-01 00:00 317 INFO.TXT 2024-01-01 00:00 17664 ERROR.TXT 2024-01-01 00:00 1585 24-11-19.CSV 2024-01-01 00:00 56448 24-11-20.CSV ... ``` Or output the content of a file (similar to `less` command on `linux`): ``` SCK > file -less 24-12-09_01.CSV 24-12-09_01.CSV ============== TIME,TEMP,HUM,BATT,SDCARD,RSSI,LIGHT,NOISE_A,SEN5X_PM_1,SEN5X_PM_25,SEN5X_PM_4,SEN5X_PM_10,SEN5X_PN_05,SEN5X_PN_1,SEN5X_PN_25,SEN5X_PN_4,SEN5X_PN_10,SEN5X_TPSIZE,AS7331_UVA,AS7331_UVB,AS7331_UVA ISO 8601,C,%,%,Present,dBm,lux,dBA,ug/m3,ug/m3,ug/m3,ug/m3,#/0.1l,#/0.1l,#/0.1l,#/0.1l,#/0.1l,um,uW/cm2,uW/cm2,uW/cm2 Time,Temperature,Humidity,Battery,SD card,WiFi RSSI,Light,Noise dBA,SEN5X PM 1.0,SEN5X PM 2.5,SEN5X PM 4.0,SEN5X PM 10.0,SEN5X PN 0.5,SEN5X PN 1.0,SEN5X PN 2.5,SEN5X PN 4.0,SEN5X PN 10.0,SEN5X Typical Particle Size,AS7331 UVA,AS7331 UVB,AS7331 UVC ,55,56,10,221,220,14,53,193,194,195,196,197,198,199,200,201,202,214,215,216 2024-12-09T12:20:05Z,21.49,42.12,-1,1,-63,176,40.77,2.90,3.00,3.00,3.00,1950.00,2270.00,2270.00,2270.00,2270.00,39.70,0.38,0.10,0.05 ``` Remove a file (be careful): ``` SCK > file -rm 24-12-09_01.CSV Deleting 24-12-09_01.CSV ``` Or output all files to `CSV` (this will take a while, be careful!!), note that there is no header between the files. ``` SCK > file -allcsv ``` !!! info "More on the shell guide" Check the [shell guide](https://docs.smartcitizen.me/guides/getting-started/using-the-shell.md) for more information. ### Debugging If you are having issues with the hardware, and you want to read the [shell](https://docs.smartcitizen.me/guides/getting-started/using-the-shell.md) output, you can enable the `debug` interface by: ``` SCK > debug -sdcard ``` This will store all the `console` output from the kit into a `DEBUG.TXT` file in the SD-card. Make sure you turn it of once done: ``` SCK > debug -sdcard ``` And check: ``` SCK > debug ... ``` !!! danger "This is an advanced feature" Make sure that you use this feature with caution and that you disable it after you are done.