Outputs four CSVs (regenerated on each run) that together let you trace any decoded value back to its source bytes and the formula that produced it:

• signals.csv — what we decoded (one row per scalar)
• frames.csv — what was on the bus (one row per consumed frame, joined to signals via frame_index)
• decoders.csv — how we decoded it (per-signal formula catalog)
• can_ids.csv — every unique CAN ID seen, with J1939 breakdown

To re-derive a value by hand: pick a row from signals.csv, look up its frame_index in frames.csv to get the raw bytes, then look up its signal in decoders.csv for the formula.

signals.csv — tidy long-format measurements

file, timestamp, frame_index, signal, value, unit

In tidy / long format. Pivot to wide from any consumer:

import pandas as pd
df = pd.read_csv("signals.csv")
wide = df.pivot_table(index="timestamp", columns="signal", values="value")

Signal names use a domain.name (or domain.NN.name) convention — cell.NN.voltage_v, pack.voltage_v, motor.rpm_signed, bms.fault.code_NNN, dm1.dtc.spn, etc. The complete list with formulas, byte positions, and confidence levels lives in decoders.csv (generated from the DECODERS table in solecan-analyze.py); the decode itself is in solecan_proto.py.

frames.csv — raw frame log

frame_index, file, timestamp, can_id, pgn, source, len, b0, b1, b2, b3, b4, b5, b6, b7

can_id is 8-hex (e.g. 18F100F3), pgn is 4-hex, source is 2-hex, each bN is the data byte at position N as 2-hex. One row per frame that produced at least one signal.

decoders.csv — per-signal decode rule catalog

signal, pgn, source, bytes, formula, unit, confidence, notes

One row per signal name (parametric signals like cell.NN.voltage_v use NN as a placeholder). bytes references positions within frames.csv's b0..b7 columns. confidence is verified, tentative, or unknown.

can_ids.csv — per-unique-CAN-ID J1939 decode

id, ext, count, priority, R, DP, PF, PS, SA, PGN, PDU, PS_role, name

solecan-stream.py — live dashboard

Live (or replayed) BMS / charger / motor dashboard. Decodes the same J1939 frames as solecan-analyze.py and serves a dashboard.

# Live capture using slcan
solecan-stream.py --interface slcan --channel /dev/cu.usbmodem101 --bitrate 250000

# Live capture using socketcan
solecan-stream.py --interface socketcan --channel can0 --bitrate 250000

# Replay an existing capture
solecan-stream.py --replay session.log

Displays pack voltage / current / DC and estimated AC power, BMS-published SOC, charger output, per-cell voltages with min/max/spread, module temperatures, vehicle-controller heartbeat, and live alerts (low/high cell, spread, temp, AC budget, stale BMS).

bms/ — UDS diagnostics dashboard

Polls UDS Data Identifiers on the BMS's separate 2-pin diagnostic port in a background thread and serves a localhost dashboard. Independent of the main-bus tools and solecan_proto.py; its DID map lives in bms/README.md.

python3 bms/solectrac-bms-diagnostics.py

Embedded firmware — esp32-s3/

ESP32-S3 firmware that re-implements the main-bus J1939 decode in C++ and exposes it as a WiFi dashboard, JSON endpoint, BLE, USB SLCAN, and socketcand. Supports the RejsaCAN, LilyGo T-2CAN, and Adafruit Feather S3. Build, wiring, and flashing are in esp32-s3/README.md.

Android app — android/

Mirrors the ESP32 dashboard over BLE so the phone doesn't need to join the tractor's WiFi. See android/README.md.

Disclaimer

This is a personal exercise based on observed CAN traffic. PGN meanings are inferred from data and may be wrong.