serial

# Serial Debugging Use this skill for UART/COM-port observation and command exchange during embedded bring-up. ## Capabilities - Scan available serial ports. - Monitor text output with filters and timestamps. - Send text or hex payloads, optionally with CR/LF and response wait. - View binary streams as hex dumps. - Record logs to text, CSV, or JSON. - Use a mux helper so monitor/log/send can share one hardware port when configured. ## Configuration Workspace-level config lives in `.embeddedskills/config.json`: ```json { "serial": { "port": "COM3", "baudrate": 115200, "bytesize": 8, "parity": "none", "stopbits": 1, "encoding": "utf-8", "timeout_sec": 1.0, "log_dir": ".embeddedskills/logs/serial" } } ``` Parameter priority: CLI arguments > workspace config > `.embeddedskills/state.json` > defaults. ## Commands Scan: ```powershell python <skill_dir>\scripts\serial_scan.py --json ``` Monitor: ```powershell python <skill_dir>\scripts\serial_monitor.py ` --port COM3 --baudrate 115200 --timestamp --timeout 10 ``` Send text: ```powershell python <skill_dir>\scripts\serial_send.py ` --port COM3 --baudrate 115200 "AT" --crlf --wait-response --json ``` Send hex: ```powershell python <skill_dir>\scripts\serial_send.py ` --port COM3 --baudrate 115200 "01 03 00 00 00 02" --hex --json ``` Hex dump: ```powershell python <skill_dir>\scripts\serial_hex.py ` --port COM3 --baudrate 115200 --timeout 10 ``` Log: ```powershell python <skill_dir>\scripts\serial_log.py ` --port COM3 --baudrate 115200 --duration 30 --timestamp --json ``` ## Rules - Never send data unless the user asks or the task clearly requires it. - Do not guess a port when multiple ports are present; ask or list candidates. - Do not guess baud rate. Use project config, firmware constants, schematic notes, or the user's value. - Prefer passive monitor/log before sending commands to an unknown device. - For binary protocols, use `hex` or `send --hex` and record exact bytes. - If a port is busy, report likely causes: another terminal, IDE monitor, flash tool, or mux state. - When using mux, warn that multiple writers can corrupt the serial stream. ## Bring-up Pattern For MCU firmware debugging: 1. Scan ports and confirm the expected adapter. 2. Monitor for reset/banner output. 3. If no output, verify baud rate, TX/RX direction, voltage domain, firmware UART init, and whether the current HEX was flashed. 4. Log evidence before changing firmware. 5. For commands, send one minimal request and wait for response.