Grade 9 · From USB to Field System: ESP32 water quality

Demonstrate and evaluate the system

Follow the student handout to build, test and document this stage of the water-quality system.

Prepared lesson material. Start this task when your teacher introduces it; it is not currently assigned homework.

For this lesson

3 pages · Use the handout for the complete instructions, examples and response spaces.

Read the handout text online

For diagrams, visual examples and the full layout, open the handout above.

Lesson 14: Demonstration and Evaluation

Final test record, evidence, and reflection

Grade 9 MYP Design | From USB to Field System

Name: __________________

Class / team: __________________

Date: __________________

Today’s goals • Demonstrate the system safely. • Judge each criterion using evidence. • Propose technically justified improvements.

☐ Wiring has passed final inspection.

☐ Buck output has been measured.

☐ Turbidity divider point is below 3.3V.

☐ Code is saved and compiles.

☐ CSV header and rows are correct.

☐ Water sample and wet zone are ready.

☐ One team member can explain every major component.

Show the protected power path and identify the fuse.

Show the buck-converter measurement.

Power the system and open Serial Monitor.

Explain GPIO4 temperature, GPIO1 conductivity, and GPIO2 turbidity.

Demonstrate a sensor response to a controlled sample change.

Capture CSV and open it in a spreadsheet.

State which readings are calibrated, estimated, or relative.

Success criterion	Evidence	Met / partly / not met	Improvement
Operates from external 12V power system
Fuse is correctly placed
Buck output is 4.9–5.1V
No raw 12V reaches ESP32/sensors
Temperature responds plausibly
EC responds to ion concentration
Turbidity responds to suspended material
GPIO2 remains below 3.3V
CSV rows occur at correct interval
Wiring has insulation and strain relief
Runs for at least ten minutes without reset

Most successful feature and evidence:

________________________________________________________________________________________________________________

Most important limitation and evidence:

________________________________________________________________________________________________________________

Highest-priority improvement, how it would work, and why it matters:

________________________________________________________________________________________________________________

What did this unit teach you that a USB LED exercise did not?

________________________________________________________________________________________________________________