Trace Qr Scan

Trace QR Scan

Trace the QR code $ARGUMENTS through the entire data pipeline in logs/IQRight_Daemon.debug.

Step 1: Search for the Code

Search the active log for all occurrences of the code. If no results, also try:

• Without leading P prefix
• With 31 prefix (known corruption pattern)
• Doubled/concatenated variant (e.g., P1234567831P12345678)

Step 2: Trace Each Occurrence Through the Pipeline

For each match, extract context (30 lines after the match) and determine:

1. Received? - Look for Received data from scanner {node}: Beacon={b}, Code={code}, Distance={d}

   • Extract: source node, sequence number, TTL (3=direct, 2=via repeater)

2. Looked up? - Look for Using local results or Using API results

   • If Couldn't find Code appears, the code was not in the database (possibly corrupted)

3. Found? - Extract student info: name, grade, hierarchyID

   • Multi-student: count how many results returned

4. Sent to scanner? - Look for Sent DATA to scanner {node}: {name}|{grade}|{id} [{index}/{total}]

   • Multi-packet: [1/4] means packet 1 of 4

5. Published to MQTT? - Look for MQTT-TX.*SUCCESS: Topic={topic}

   • Verify topic format: Class{hierarchyID} for student data, IQRSend for commands
   • If MQTT-TX.*FAILED: note Status code (7 = connection lost)

Step 3: Identify Where It Broke

If the trace breaks at any stage:

• Not received: LoRa signal/hardware issue
• Not looked up: Code pipeline bug
• Not found: Code not in DB, or corrupted (check for 31 prefix, null bytes, duplicated codes)
• Not sent: LoRa transmission failure (check Error in sendDataScanner)
• Not published: MQTT broker connection lost

Output Format

Show the trace as a timeline:

Code: P22510583
Occurrences: 3

[1] 2025-12-17 15:21:30
  1. Received:  OK - Scanner 102, seq=4, TTL=3 (direct)
  2. Lookup:    OK - Local (API offline)
  3. Found:     OK - 2 students (Raphael Winata, Gabriel Winata)
  4. Sent:      OK - [1/2] and [2/2] to scanner 102
  5. Published: OK - Topic=Class89 and Topic=Class103

[2] 2025-12-17 10:49:26
  1. Received:  OK - Scanner 102, seq=38, TTL=2 (via repeater)
  2. Lookup:    FAILED - Corrupted code: "\x00\x00\x01\x0031P22510583"
  3. Found:     N/A
  4. Sent:      N/A
  5. Published: N/A
  DIAGNOSIS: QR scanner buffer corruption (PATTERN-001)

Reference: See docs/LOG_ANALYSIS_SKILLS.md sections 2-5 for pipeline stages and known patterns.