Connected hardware · EV batteries · In development
Diagnostics and control for EV battery packs.
A custom gateway that speaks to the battery management system over UART and to a technician’s phone over BLE — with every parameter change signed into an audit ledger.
JBD BMS
Battery management · protection, balancing, state of charge
Custom gateway
Our own firmware · secure BLE · byte-level contract
Technician app
Live instrumentation · on-site parameter writes
Broker + ledger
Policy, remote commands, signed audit trail
Pack KEV-0217 · live
BLE -58 dBm
78%
SOC
Pack
53.07 V
Current
-16.2 A
Temp
32.0 °C
Δ cell
46 mV
UART frames
- TXDD A5 03 00 FF FD 77read basic info
- RXDD 03 00 1B 14 A2 FB 3C …pack status
- TXDD A5 04 00 FF FC 77read cell voltages
- RXDD 04 00 20 0C D8 0C DA …16 cells
Audit ledger
Cell OVP
tech-014 · on site
3.65 V → 3.60 V
Charge OCP
support · remote
40 A → 35 A
Balance start
tech-009 · on site
3.40 V → 3.38 V
Illustrative readout. Pack data shown is simulated.
The challenge
Battery packs are serviced in the field with laptop tools and no record of who changed what. Fleets need live diagnostics, safe remote writes and an audit trail.
What we built
Three codebases, one product: firmware on the gateway, a technician app for live instrumentation and on-site writes, and an API that brokers commands, enforces policy and keeps the ledger.
Highlights
- Byte-level BLE contract shared and tested by firmware and app
- Command broker for safe remote parameter writes
- Immutable audit ledger of every change
- Installable PWA plus native iOS and Android builds
Stack
Next project
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