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.
npx skills add HermeticOrmus/LibreEmbed-Claude-Code --skill communication-busesgit clone --depth 1 https://github.com/HermeticOrmus/LibreEmbed-Claude-CodeWrote 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.
[](https://agentmods.dev/skills/hermeticormus/libreembed-claude-code/communication-buses)<a href="https://agentmods.dev/skills/hermeticormus/libreembed-claude-code/communication-buses"><img src="https://agentmods.dev/badge/skills/hermeticormus/libreembed-claude-code/communication-buses/github.svg" alt="Measured on agentmods" height="20"></a>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.
<a href="https://agentmods.dev/skills/hermeticormus/libreembed-claude-code/communication-buses"><img src="https://agentmods.dev/badge/skills/hermeticormus/libreembed-claude-code/communication-buses.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00075 | $0.04189 |
| Opus 5.5 | $0.00030 | $0.01676 |
| Sonnet 5.5 | $0.00015 | $0.00838 |
| Haiku 4.5 | $0.00007 | $0.00419 |
Grade A, and why
communication-buses 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 15d 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.
How it starts
The opening of the file, as written. The whole thing — 471 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Communication buses pattern library
Reference patterns for I2C, SPI, UART, CAN, and USB driver development. Use as a lookup when designing or reviewing drivers.
I2C reference
Address resolution
| Address space | Bits | Range |
|---|---|---|
| 7-bit | bits 7..1 | 0x08–0x77 (0x00-0x07 and 0x78-0x7F reserved) |
| 10-bit | bits 9..0 | 0x000–0x3FF |
Format on the wire (7-bit):
S | 7-bit addr | R/W | A | ... | P
The R/W bit is bit 0. Many HALs accept the address pre-shifted (address << 1); some accept it raw. Confirm against the HAL docs — common bug source.
Pull-up sizing
For VCC = 3.3V:
| Speed | Recommended pull-up |
|---|---|
| Standard (100 kHz) | 4.7 kΩ |
| Fast (400 kHz) | 4.7 kΩ or 2.2 kΩ |
| Fast Plus (1 MHz) | 2.2 kΩ or 1 kΩ |
| High Speed (3.4 MHz) | 1 kΩ + external buffer |
Bus capacitance matters. Wire capacitance ~ 1 pF/cm. Total bus capacitance (wire + slaves + master) should be < 400 pF for standard, < 200 pF for fast modes.
Clock stretching
Slave holds SCL low to gain processing time. Master must wait. STM32 hardware I2C handles this. Some software bit-bang implementations don't. If using bit-bang, sample SCL before assuming the master controls it.
Bus recovery
When SDA is stuck low (slave hung mid-transfer):
1. Configure SDA + SCL as GPIO (out of AF)
2. Pulse SCL low → high, 9-16 times
3. Check if SDA released (high)
4. If yes: generate STOP (SCL high, SDA low → high)
5. Restore SDA + SCL to AF
6. Re-init the I2C peripheral
SPI reference
Mode card
| Mode | CPOL | CPHA | Idle clock | Data captured on |
|---|---|---|---|---|
| 0 | 0 | 0 | Low | Rising edge |
| 1 | 0 | 1 | Low | Falling edge |
| 2 | 1 | 0 | High | Falling edge |
| 3 | 1 | 1 | High | Rising edge |
Most sensors: mode 0 or 3. Always verify against datasheet — wrong mode silently corrupts every byte.
CS line patterns
Hardware NSS (single slave):
- Peripheral toggles NSS automatically
- Faster setup/hold timing
- Limited to one slave
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.
- 15d ago First seen · 471 lines · 75 tokens per session scan A 39b4d25da898
communication-buses is a skill published in the GitHub repository HermeticOrmus/LibreEmbed-Claude-Code (50 stars, last pushed 6d ago), licensed MIT. It adds 75 tokens to every session and 4,189 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-10-01.
Other skills, from other repositories
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Produce a complete firmware architecture spec for a described device — layer diagram, module responsibilities, HAL interface definitions, key state machines, RTOS decision. Use when asked to "design firmware architecture", "plan embedded firmware", "architect an IoT device", "how should I structure this firmware", or…
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Build a device driver or protocol handler — I2C sensors, BLE services, MQTT clients, SPI peripherals with interrupt-driven I/O and clean HAL abstraction. Use when asked to "write a driver", "I2C device", "BLE service", "MQTT client", or "sensor integration".
volt-power
Power management audit — analyze sleep modes, wake sources, power state machines, radio duty cycles, and battery life estimates. Use when asked to "audit power usage", "optimize battery life", "review power management", "why is my battery draining", "power budget analysis", or "sleep mode review".
volt-recon
Firmware reconnaissance for takeover — inventory the MCU, peripherals, RTOS, protocols, OTA, power management, and assess code quality with risk flags. Use when asked to "understand this firmware", "device inventory", or "embedded assessment".
iot-expert
Expert-level IoT systems, embedded devices, edge computing, and IoT protocols. Use when the user mentions embedded, edge computing, MQTT, sensors, or firmware, or when the task involves IoT Architecture, IoT Protocols, Embedded Systems, or Device Design.