8051-mcu-debug

8051-mcu-debug is a skill for Claude Code, Codex from easyzoom/aix-skills. It costs 41 tokens per session (2,242 once invoked), scanned A, original, MIT.

A troubleshooting guide for 8051-compatible microcontrollers, an older family of small embedded processors, and their firmware. It covers common chips, compilers, programming tools, interrupts, timers, UART serial communication, and startup behavior.

In plain words
What is it for?
Use it for STC, Nuvoton, Silicon Labs, Atmel, WCH, and other 8051-like devices, including Keil C51 or SDCC projects, ISP or IAP downloads, SFRs, timers, interrupts, and UART debugging.
Why use it?
It provides a structured way to investigate firmware that will not download, run after reset, print serial output, or respond through its peripherals. It starts with observable checks before changing boot or clock settings.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it for STC, Nuvoton, Silicon Labs, Atmel, WCH, and other 8051-like devices, including Keil C51 or SDCC projects, ISP or IAP downloads, SFRs, timers, interrupts, and UART debugging.

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Install with agentmods
npx agentmods add skills/easyzoom/aix-skills/8051-mcu-debug
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add easyzoom/aix-skills --skill 8051-mcu-debug
Clone the repo
git clone --depth 1 https://github.com/easyzoom/aix-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for 8051-mcu-debug

README.md
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Your own site
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

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Your own site · 80×15
<a href="https://agentmods.dev/skills/easyzoom/aix-skills/8051-mcu-debug"><img src="https://agentmods.dev/badge/skills/easyzoom/aix-skills/8051-mcu-debug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,242 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00041 $0.02242
Opus 5 $0.00020 $0.01121
Sonnet 5 $0.00008 $0.00448
Haiku 4.5 $0.00004 $0.00224

Measured 10d ago against content hash cf0e011a012f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

8051-mcu-debug scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/8051-mcu-debug/SKILL.md · 226 lines

How it starts

The opening of the file, as written. The whole thing — 226 lines — stays where its author put it; the contents beside it link to each section on GitHub.

8051 MCU Debug

Overview

Use this skill to debug 8051-compatible microcontrollers and 51 MCU firmware systematically. Start by identifying the exact chip family, clock source, download method, toolchain, and failure phase, then prefer observable checks such as reset behavior, UART logs, GPIO toggles, interrupts, and SFR state before changing fuses or boot settings.

When To Use

Use this skill when:

  • The target is an 8051-compatible MCU, such as STC 89/90/12/15/8 series, Nuvoton N76/N79, Silicon Labs C8051, AT89, WCH 8051-like parts, or classic MCS-51 derivatives.
  • The user mentions 51 单片机, 8051, Keil C51, SDCC, STC-ISP, ISP/IAP, UART download, REG52.H, intrins.h, SFR, interrupt vectors, timers, or serial debugging.
  • Firmware cannot download, does not run after reset, has no serial output, timer/interrupt behavior is wrong, or peripherals do not respond.

Do not use this skill when:

  • The target is Cortex-M, RISC-V, AVR, ESP32, embedded Linux, or another non-8051 architecture.
  • The task is only generic C syntax cleanup and does not depend on MCU behavior.
  • The user wants to change lock bits, fuses, clock source, or boot configuration before collecting baseline evidence.

First Questions

Ask for the minimum context needed:

  • Exact MCU model and board name.
  • Toolchain: Keil C51, SDCC, IAR, vendor IDE, or other.
  • Download tool: STC-ISP, Nu-Link, C2 debugger, USB programmer, UART bootloader, or ISP adapter.
  • Current symptom: cannot download, no boot, no UART output, timer wrong, interrupt not entered, reset loop, or peripheral failure.
  • Clock source and frequency: internal RC, external crystal, PLL, divider, or unknown.
  • Power voltage and whether reset, crystal, and UART pins are accessible.
  • Available artifacts: source, HEX/IHX, MAP/M51 file, schematic, UART log, programmer output, or logic analyzer capture.

Workflow

  1. Identify the chip family. 8051 derivatives differ heavily. Confirm the exact part number before assuming SFR names, memory model, bootloader behavior, or download protocol.

Read the full file on GitHub · 226 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 10d ago First seen · 226 lines · 41 tokens per session scan A cf0e011a012f

Subscribe to this mod's changes

8051-mcu-debug is a skill published in the GitHub repository easyzoom/aix-skills (31 stars, last pushed 1mo ago), licensed MIT. It adds 41 tokens to every session and 2,242 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.