55.6%. That's DeepSeek-R1's pass@1 on EmbedBench when it gets a circuit schematic alongside the task description. 50.0% without the schematic. Best score from the best reasoning model on the first comprehensive benchmark for LLMs in embedded systems development. Cross-platform migration to ESP-IDF tops out at 29.4%, set by Claude 3.7 Sonnet (Thinking). Take a second with that. The same models that one-shot a Next.js app are coin-flipping firmware. And the benchmark only tested three boards. That 1,553 number is the live count from pio boards --json-output against PlatformIO Core 6.1.18 on the day this post was written, and PlatformIO-MCP wraps that catalog directly. So when we say "1,553 boards," we mean an MCP server you can npx -install today that knows how to build, flash, and monitor against any of them. What EmbedBench actually measures EmbedAgent (Wang et al., 2025) is the paper. EmbedBench is the benchmark.…