Light-sensor interface repair

Steps

Screens captured against IoT Ideator aa0f6c2f299ef9404864df05928c6856471a9a98 on 2026-09-05; the tool may have moved on — the text steps are the contract.

1. 1 Step 1

   Do

   In the Site canvas, select the light sensor and inspect its I2C connection to the ESP32.

   You will see

   The prepared connection shows an I2C distance warning because it exceeds the model’s 1 m limit.

   Why it matters

   The chapter treats I2C as a shared link for nearby parts. Cable length is one piece of evidence when a bus fails.

2. 2 Step 2

   Do

   In the Site canvas, drag the light sensor toward ESP32 until Physical placement shows a cable length below 1 m.

   You will see

   Physical placement reports less than 1 m, and the I2C distance warning clears.

   Why it matters

   Moving one part isolates the length condition. The chapter also checks pull-ups, clock speed, and signal integrity before declaring a bus usable.

3. 3 Step 3

   Do

   In the Communication panel, add Bidirectional Logic-Level Shifter and place it between ESP32 and the relay on the Site canvas.

   You will see

   The shifter appears with separate low-voltage and high-voltage digital ports.

   Why it matters

   GPIO provides a direct control line. The chapter’s logic-threshold checks explain why that line must meet the receiving input’s electrical limits.

4. 4 Step 4

   Do

   In the Site canvas, replace the direct ESP32–relay link with ESP32 GPIO–shifter 3.3 V and shifter 5 V–relay control links.

   You will see

   The controller connects to the shifter’s 3.3 V side, and the relay control connects to its 5 V side.

   Why it matters

   The two sides make the voltage boundary visible in the design. A drawn link still needs the chapter’s electrical checks on real hardware.

5. 5 Step 5

   Do

   In the Scenarios panel, read the connected-shifter, complete-control-path, and valid-link checkpoints.

   You will see

   All three checkpoints pass for the sensor–controller–relay route. They do not report a measured light threshold.

   Why it matters

   A complete path establishes which parts can exchange the modelled signals. The chapter also records raw data, units, timing, and error state to support interpretation.

6. 6 Step 6

   Do

   In a browser tab, open the linked chapter knowledge check and answer the address-conflict and bus-selection questions.

   You will see

   The questions test I2C addresses and interface choices separately from the model’s cable and voltage checks.

   Why it matters

   I2C uses addresses to distinguish parts sharing its lines. Fixing cable length or logic levels does not assign different addresses to conflicting devices.