COMMAND BEHAVIOR SUMMARY
========================

PING
----
Format:
    PING

Response:
    Analog_System_Monitor_<version>

Purpose:
    - Confirms the device is alive
    - Allows PC-side auto-discovery
    - Returns firmware version


SETALL
------
Format:
    SETALL: v0,v1,v2,v3,v4,v5,v6,v7

Rules:
    - Exactly 8 comma-separated values
    - Each value must be numeric
    - Each value must be between 0 and 100
    - No extra values allowed
    - No missing values allowed
    - No trailing commas or extra characters

Success Response:
    OK

Error Response:
    ERROR

Purpose:
    - Updates all 8 channels in one atomic operation
    - Applies calibration to each channel
    - Resets watchdog timer


UNKNOWN / MALFORMED COMMANDS
----------------------------
Format:
    Anything not matching PING or a valid SETALL command

Response:
    ERROR

Purpose:
    - Keeps protocol strict and predictable
    - Prevents accidental meter movement
    - Simplifies debugging
