Architecture & Goals

Architecture & Engineering Goals

Hard quantitative engineering targets that define Pyintel Lux. Every design decision in Lux is measured against these metrics.

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1. Why Pyintel Lux?

Cloud telemetry frameworks like OpenTelemetry assume:

• A dynamic heap allocator is available (malloc / free).
• Megabytes of available RAM and Flash storage.
• A full OS network stack (TCP/IP, HTTP/2, gRPC, TLS).
• Ample CPU headroom for runtime JSON / Protobuf string serialization.
• A stable, continuous internet connection to a cloud collector.

None of these assumptions hold on bare-metal microcontrollers, industrial CAN buses, real-time robotics, or battery-powered wireless sensor nodes. Pyintel Lux was engineered specifically for edge microcontrollers from the opposite set of constraints.

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2. Memory Footprint Targets

Metric	OpenTelemetry (OTel C++)	Pyintel Lux Target	Measured Status
Flash Footprint (MCU)	~200–500 KB	< 4 KB	Verified (< 3.2 KB C core)
Static RAM on MCU	~50–200 KB	< 1 KB	Verified (Static allocation)
Heap Allocation at Runtime	Required (malloc)	Zero	Verified (no_std / zero malloc)
Stack Usage per Emit Call	Variable	< 64 bytes	Verified
Ingest Proxy Binary Size	N/A	< 5 MB	Verified (luxd Rust binary)

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3. Wire Protocol Efficiency

Metric	OTLP / JSON	OTLP / Protobuf	Pyintel Lux
Min. Event Frame Size	~150–400 bytes	~40–80 bytes	14 bytes
Fixed Header Overhead	~100 bytes	~20 bytes	14 bytes
String Data on Wire	Full UTF-8 strings	Full UTF-8 strings	Zero (16-bit Token IDs)
Runtime String Formatting	Required	Required	Never (Compile-time tokenization)
Payload Size Reduction vs JSON	—	~60%	70–90%
CRC Protection	Relies on Transport/TLS	Relies on Transport/TLS	CRC-16/CCITT per frame

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4. Transfer Speed & Throughput

Transport Bearer	Target Frame Rate	Notes
UART @ 115200 baud	~800 frames/sec	14-byte min frame (~10–14 bytes on wire)
UART @ 921600 baud	~6,500 frames/sec	High-speed USB-Serial
UDP (Local LAN)	~50,000 frames/sec	MTU-limited single socket stream
ESP-NOW	~700 frames/sec	250-byte max payload, ~1ms latency
CAN 2.0 @ 1 Mbps	~500 frames/sec	8-byte CAN payload fitting single arg
CAN-FD @ 8 Mbps	~4,000 frames/sec	64-byte CAN-FD payload fitting full frame
WebSocket (Local)	~10,000 frames/sec	Browser dashboard live stream

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5. Execution Latency Targets

Metric	Target	Verified Performance
lux_emit_u32() execution time on ESP32 @ 240MHz	< 2 µs	4.00 µs (includes UART transmit FIFO fill)
UART Frame-to-Host Latency (115200 baud)	< 1.5 ms	~1.1 ms
UDP Frame-to-Host Latency (Local LAN)	< 2 ms	< 1.2 ms
ESP-NOW Node-to-Node Latency	< 5 ms	4.06 ms
luxd Ingest-to-SQLite Write Latency	< 10 ms	~2.4 ms
luxd-to-Browser WebSocket Latency	< 50 ms	< 15 ms