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All case studies
train
Rail / Safety-Critical
Locomotive Controller Migration
Legacy CAN → nRF5340 + BLE
Migrated a legacy locomotive controller onto a new nRF5340 board — behaviourally feature-identical to the original CAN controller, including man-down operator safety — with an added BLE backhaul and companion app for testing and diagnostics.
Feature-identical
To the legacy unit
Man-down
Auto-stop safety preserved
New path
Wireless diagnostics added
- Client
- A US rail / locomotive company (name withheld — NDA)
- Delivery
- Delivered by our founder at Croxel Inc (US)
- Role
- Embedded developer — PoC firmware and migration
- Timeline
- 2022 – 2023
Stack
nRF5340 Zephyr / nRF Connect SDK CAN BLE Flutter
help The problem
The client ran a locomotive controller on older hardware and wanted it on a modern Nordic platform — without changing how it behaves. In locomotive control, "feature-identical" is a hard requirement: the migrated board has to speak the same CAN messages and drive the same logic as the unit it replaces, so it drops into the existing system transparently.
build What we built
- A feature-identical re-implementation of the legacy CAN controller on a new nRF5340 board, matching the original's behaviour including CAN message encoding/decoding and multiplexing between the system's modules.
- Man-down operator safety: dual-accelerometer processing that detects when the operator has gone down and automatically stops the locomotive — carried faithfully from the legacy unit.
- A BLE backhaul alongside the CAN interface — a wireless path into the controller the legacy design never had.
- A companion Flutter app that connects over BLE to exercise the controller, relay data and diagnose behaviour, including simultaneous connections for multi-point diagnostics.
check_circle The result
- done A working proof-of-concept demonstrating the legacy controller's functionality on modern hardware, plus a wireless diagnostics path that did not exist before.
- done Legacy-system migration with behavioural fidelity, CAN bus firmware, and modern wireless diagnostics layered onto an industrial control product.