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title: Troubleshooting Decision Tree description: Walk a clickable troubleshooting tree for Pico clocks: pick a symptom, answer yes or no questions, and reach a likely cause, the test to run and the chapter to review. image: /sims/troubleshooting-decision-tree/troubleshooting-decision-tree.png og:image: /sims/troubleshooting-decision-tree/troubleshooting-decision-tree.png twitter:image: /sims/troubleshooting-decision-tree/troubleshooting-decision-tree.png social: cards: false quality_score: 0

Troubleshooting Decision Tree

Run the Troubleshooting Decision Tree MicroSim Fullscreen

About This MicroSim

Most clock problems fall into a few families. This decision tree turns the troubleshooting table in Chapter 20 into a path you can follow one question at a time, always checking the cheapest and most likely cause first.

The first view shows the five symptom families:

  • Nothing on the display
  • Wrong image (colors, noise, offset)
  • Wrong time
  • Buttons misbehave
  • Random resets

Click a symptom to draw its branch. Orange six-sided boxes are questions with yes and no arrows, and green boxes are suggested fixes. Every box is clickable. The panel on the right explains why that question is asked and the exact test to run, and each fix names the chapter to review. The yellow box marks where you are, the boxes on the path from the top have a dark blue outline, and the breadcrumb at the top lists the answers you have given so far.

How to Use

  1. Click the symptom that matches your problem.
  2. Read the question and the test to run in the right panel. Do the test on your clock.
  3. Click the yes or no box under the question to follow your answer.
  4. When you reach a green fix, apply it and test again.
  5. Hover over any box to preview its details. Press Start over to return to the top.

Iframe Embed Code

You can add this MicroSim to any web page by adding this to your HTML:

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<iframe src="https://dmccreary.github.io/clocks-and-watches/sims/troubleshooting-decision-tree/main.html"
        height="602px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

9-12 (Clocks and Watches with AI)

Duration

15-20 minutes

Prerequisites

  • The troubleshooting table and systematic debugging steps in Chapter 20
  • Running an I2C scan and reading a traceback

Learning Objectives

Students will be able to:

  • Analyze a symptom and select the most likely cause
  • Choose the next test that best splits the remaining possible causes
  • Explain why power and wiring are checked before code

Activities

  1. Case studies (8 min): For each case, walk the tree and record the path and the fix: (a) an OLED clock shows nothing, the 3.3 V rail is fine, and i2c.scan() returns []; (b) a clock shows 2021-01-01 every morning after the power strip is switched off; (c) the mode button skips two modes at a time.
  2. Why this order? (4 min): In the Nothing on the display branch, why is the power test asked before the I2C scan, and the scan before checking show()? What would you waste if you started with the code?
  3. Extend the tree (6 min): Choose one branch and design one more question and fix that is not in the tree (for example, for WiFi that will not connect). Write the question, the test, and the yes and no outcomes.

Assessment

  • The student reaches the correct fix for each case study and names the test that decided each step.
  • The student explains the "cheapest, most likely first" ordering.
  • The student's new question has a clear, quick test that splits the possible causes.

References

  1. Troubleshooting - Wikipedia article on systematic problem solving and the half-splitting method.
  2. Decision tree - Wikipedia article on decision trees as a way to organize choices.
  3. MicroPython I2C class - Official documentation for scan() and the other I2C calls used in the tests.
  4. Mermaid flowchart syntax - The diagram library and the click directive that make each box clickable.