Developer Tools

Framecairn: CAN Decoder

Map Raw Frames & Signals

iOSfor iPhone and iPad

  • $1.99 one-time purchase
  • No account
  • No ads or app telemetry

View on the App Store

About Framecairn: CAN Decoder

Framecairn is a pocket workbench for decoding CAN frame payloads and sanity-checking bus load — all on one fast screen.

Type eight data bytes in hex into the frame field and everything below updates instantly. A 64-bit map colors each bit by the signal that owns it, so you can see exactly where every field sits in the payload. The Decoded fixture section extracts the built-in signals — wheel speed, motor torque, and temperature — applying each one's start bit, length, factor, and offset to turn raw bits into physical values. The Bus budget section estimates utilization at 500 kbit/s: drag the frame-rate slider anywhere from 10 to 3,000 frames per second and watch the load bar, which turns red past 70%. An overlap check confirms the signal definitions never collide.

FEATURES
• Live hex payload decoding — results update as you type
• Color-coded 64-bit ownership map of the frame
• Factor/offset scaling from raw bits to physical values
• Bus-load estimator with bit-stuffing overhead built in
• Automatic signal-overlap detection
• Monospaced readouts and VoiceOver labels on every bit cell

PREMIUM BY DESIGN
One-time purchase. No account, no ads, no analytics, no tracking, and no network access — Framecairn works entirely offline.

A Shadowfetch app. Published on the App Store by Robert Corbin.