Technologies K–10 · Years 7–8

Logging light levels with a micro:bit and validating the data

Digital and Communication Technologies focus area (NSW Technology 7–8, 2023); Digital Technologies: Processes and production skills, Acquiring, managing and analysing data (ACARA v9)

PracticalLow risk

The idea

Sensor data must be checked against what the sensor can report and the planned sampling times before it is queried and graphed for trends.

What you need

1 BBC micro:bit V2 with a battery pack, programmed with the MakeCode data logger extension
Computer with a spreadsheet
The ACARA Digital Technologies in focus light table (micro:bit value against lux)

How to do it

Program the micro:bit to log the light level with a timestamp every 10 minutes, with columns named time and light.
Place it beside a classroom window for 6 hours and record events in a paper log (lights on or off, blinds, cloud).
Open MY_DATA on the micro:bit drive, download the CSV and import it into the spreadsheet.
Validate: flag any value that is not a whole number from 0 to 255, any gap between timestamps other than 10 minutes, and any duplicate rows.
Query the valid rows: filter for readings of 100 or more and count them; sort by light level.
Graph light against time, mark the paper-log events, describe the trend and predict tomorrow's reading at the same time.

What you should see

6 hours at 10-minute intervals gives 37 readings, counting the first. Every valid value is a whole number from 0 to 255, so anything else, or a missing time, is flagged. The graph rises through the morning near the window and drops sharply when the lights go off or cloud passes, matching the paper log. Readings of 255 mean the sensor has reached its ceiling, not that the light stopped rising. On the ACARA table a reading of 100 matches about 500 lux, the level described as acceptable for reading, so the filter counts the acceptable readings. The learner knows it worked when every flagged row has a stated reason and each sharp change lines up with a logged event.

What changes

This activity lists no variables to change, measure and keep the same.

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

Data from a sensor is always correct (sensors have limits, and logging can miss or repeat rows).
A missing row can be filled with any sensible number (gaps must be flagged, not invented).
A flat top at 255 means the light was steady (it means the sensor was at its maximum).

Safety card

Low riskLearners carry it out

Hazards

Device left on a sunny sill overheating

Controls

Place the micro:bit out of direct sun inside the window

Note

No chemicals or heat.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Technology 7–8 Syllabus (2023), NESA. Current: taught from 2026. Code read from the outcomes page on 2026-09-22.TE4-DIG-02
Technology Mandatory 7–8 Syllabus (2017), NESA. Outgoing: replaced by the Technology 7–8 Syllabus (2023) from 2026 and not available after December 2027. Code read from the official syllabus document (DOCX) on 2026-09-22.TE4-7DI
Australian Curriculum v9AC9TDI8P01AC9TDI8P02AC9TDI8P03

Sources

The pages the author read to write this activity.

All Concept Studio activities