Logging

The Logging blocks, shown in Fig. 55, provide a facility for writing data into files on the Kookaberry.

Note

At present KookaBlockly does not directly support the reading of files from the Kookaberry’s file system. MicroPython scripting does however contain extensive functionality for reading, writing and manipulating the Kookaberry’s files. In the Advanced Category there is an example of using Python blocks to read a text file.

The Kookaberry contains a 3 to 4 megabyte (depending on hardware model) non-volatile serial memory store which is used to store files. These files can be written and read by the Kookaberry and also via a USB interface by any attached computer.

Logging files are text files which are in the comma-separated-values (CSV) format. That is, each line contains alphanumeric text data which are separated by commas. The first line of the files can be used to represent headings for the data item columns that are in the following lines. An example of a CSV file is:

Time,Temperature,Humidity
12:04:00,25,50
12:09:00,26,49
12:14:00,27,48
etc

During experiments, data is collected over time from instruments comprising sensors. These data are stored in a CSV file at time intervals as above.

When the experiment is finished, the data can be retrieved from the CSV file stored on the Kookaberry using a computer to perform analysis of the results. CSV text data is most commonly used to draw graphs of the data values over time using a spreadsheet program.

Clear File

The file block creates a new empty text file with the specified name in the Kookaberry’s file system. If a file with the same name already exists, then it will overwritten with an empty file.

The name of the file is specified in the to file parameter with log.csv the default name. Edit this field to change the file name. This can be any legal filename, usually in the form name.typ where name is a text string and typ is a short, usually three letter, file type description.

CSV is the recommended file type, but other common types are: txt for text files, and log for log text files. File type conventions are determined by the computer operating system that will read these files.

Log To File

The Log To File block writes the text provided by the attached value block(s) as a new line appended to the named text file. If the text file name does not already exist, a new empty text file with the specified name will be created.

The value blocks attached as inputs to this block will provide text values to be written to the line in the file, separated by commas.

The first input, by default, is a text representation of the current time read from the Kookaberry’s internal clock. This input block can be replaced by any other value block that provides a text string.

There are three varieties of the Log To File block, accepting one two or three further inputs. These inputs are also expected to be text string representations of the data to be recorded in the file record.

To create a heading line in the CSV file, use the appropriate Log To File block first within an On Start control block and plug in text string value blocks with the names of each of the columns.

Note

KookaBlockly presently supports a maximum of four data items per file record inclusive of the time string input.

If logging the time is not needed, then the time string can be replaced with some other string input.

If more data items are required then it is possible to use an Advanced block with the required MicroPython script in it.

The Show Script button on the KookaBlockly editor will open a window with the MicroPython script derived from the current KookaBlockly script.

Hint: Use a Log To File block to model the first four data items, copy the equivalent MicroPython (it all has to be on one line), paste it into the Advanced block and modify it to suit your application.

You will need to learn about MicroPython nonetheless to make it work correctly.