---
type: reference
---
# Bill of Materials

## PEAK-System PCAN-USB

| Field | Value |
|-------|-------|
| **Manufacturer** | PEAK-System Technik GmbH |
| **Model** | PCAN-USB |
| **USB ID** | `0c72:000c` |
| **Purpose** | USB-to-CAN adapter for reading car CAN bus traffic |
| **Interface** | SocketCAN netdev |
| **Bitrate** | 500 kbps, measured on the Z27AG OBD port (listen-only by default; see [CAN bitrate plan](impl/plans/CAN-BITRATE.md)) |
| **Driver** | PEAK proprietary driver 9.2.0 (netdev build) — out-of-tree module, must be rebuilt after kernel updates |

### Notes

- The mainline kernel driver `peak_usb` is not compiled into the NVIDIA Tegra kernel (JetPack r36.4), so PEAK's proprietary driver is required.
- Must be built with `NET=NETDEV_SUPPORT` for standard SocketCAN tools (`candump`, `ip link`, etc.).
- The module lives at `/lib/modules/$(uname -r)/misc/pcan.ko` and is loaded via `modprobe pcan`.
- Jetson Orin Nano has a built-in CAN controller (exposed by GPIO pins). Kernel `canN` order is not stable, so both are pinned by udev: onboard → `can_onboard`, PCAN-USB → `can_pcan` ([device naming](impl/reports/DEVICE-NAMING.md)).  

## Waveshare SIM7600G-H-M.2

[hat](https://www.waveshare.com/wiki/SIM7600G-H-M2_4G_HAT) [module](https://www.waveshare.com/wiki/SIM7600G-H-M.2)  

| Field | Value |
|-------|-------|
| **Manufacturer** | Waveshare (SIMCom SIM7600G-H-M.2 module) |
| **Form factor** | M.2 B KEY |
| **Purpose** | LTE Cat 4 cellular + multi-constellation GNSS (GPS, Beidou, GLONASS, GALILEO, QZSS) |
| **Interface** | USB (ttyUSB* for AT commands/NMEA, QMI `cdc-wdm0` + `wwan0` for data) |
| **Power** | 3V – 4.2V (board rail) |
| **Antennas** | 3× IPEX (LTE main + LTE diversity + GNSS) |
| **Max data rate** | 150 Mbps DL / 50 Mbps UL (LTE Cat 4) |

### Required software

| Package | Purpose |
|---------|---------|
| `gpsd` | Decode NMEA from the GNSS ttyUSB port |
| `ModemManager` + `NetworkManager` | Manage the modem and the LTE data connection (QMI) |
| `qmi_wwan` + `cdc-wdm` kernel modules | Not in the Tegra kernel; built out of tree in `~/infra/qmi_wwan/` |
| `minicom` (or `picocom`) | AT command terminal for module configuration |

### Notes

- The module presents multiple USB serial ports (`/dev/ttyUSB0`–`/dev/ttyUSB4`) — ttyUSB2/3 for AT commands, ttyUSB1 for NMEA GPS data (symlinked as `/dev/sim7600-gps`).
- Default USB composition (PID 9001) is used with QMI; no PID switch needed. PPP dial-up does not work with the povo SIM (network detaches).
- Setup details: [SIM7600 setup report](impl/reports/SIM7600-SETUP.md).
- M.2 B KEY is **not** mechanically compatible with Mini-PCIe.
- Supply voltage should be ~4.0 V for reliable operation.
- DO NOT hot-plug while powered.

## Waveshare UPS Power Module (C)

[wiki](https://www.waveshare.com/wiki/UPS_Power_Module_(C))

| Field | Value |
|-------|-------|
| **Purpose** | Keep the Orin running through cranking and short power losses, and give time for a clean shutdown at ignition off |
| **Input** | 15–19 V DC (Waveshare recommends a 19 V / 2.37 A adapter). ⚠ A PD trigger at the standard 20 V level is above the rated maximum |
| **Output** | Input voltage when powered (pass-through); battery voltage (9–12.6 V) when not |
| **Battery** | 3 × 21700 Li-ion in series (not included); charging stops when full and resumes below 12 V |
| **Monitoring** | INA219 on I²C. On the car unit it is **bus 7 (40-pin header), address `0x41`** |
| **Holdover (bench, 2026-10-09)** | ≥ 20 s across a supply swap, enough to ride through cranking |

### Notes

- First read-only check (2026-10-09, on input power, charged): bus 12.34 V, shunt ≈ 0 mV (idle). Chip at power-on defaults (config `0x399f`,
  calibration unprogrammed), so read current from the **shunt-voltage register** (0x01, 10 µV/LSB) rather than the current register.
- Fed from the ignition-switched cigarette socket via a **15 V PD trigger** (15 V / 3 A, inside the 15–19 V rating). Plan: [car power](impl/plans/POWER.md).
- Ignition-off shutdown (not built yet): on input loss the battery current turns clearly negative (discharging). A small service watches the
  INA219, waits out a grace period longer than a crank (30–60 s), then runs `systemctl poweroff`, with low battery voltage as a hard backstop.
  The shunt value is unconfirmed; check the schematic before converting shunt mV to amps.
- No GPIO or shutdown signal on the module; the BOOT button may be needed to wake a battery that stopped outputting (FAQ).

## RTC backup battery

**Status: optional, low priority.** Battery choice settled (CR2032); footprint/R560 still to verify against NVIDIA's schematic.

| Field | Value |
|-------|-------|
| **Purpose** | Keep the RTC (`rtc0`, `nvvrs-pseq-rtc`) running while the board is unpowered, so the clock is correct at boot without network or GPS |
| **Carrier board** | P3768 (Orin Nano Developer Kit): pads present, **connector not populated** (needs soldering) |
| **Connector (per NVIDIA docs, as quoted on the forum)** | Wieson AC2651-0011-003-HH, 2-pin, 1.25 mm pitch. A community-used substitute is Molex 53398-0271 header + 51021-0200 housing |
| **Battery** | **CR2032** (primary 3 V lithium) in a holder with leads. **Not ML2032 or other rechargeables:** the module datasheet says the backup pin (PMIC_BBAT) does not support charging, so a rechargeable just drains, and it has ~⅓ of the capacity |
| **Expected life** | RTC draws 12–50 µA while unpowered (~15 µA measured on the forum) → CR2032 (~220 mAh) lasts ~1.5–2 years typical, ~6 months worst case. Drains only while the board has no power |
| **Extra parts** | Forum reports also populating R560 (0.56 Ω, e.g. Panasonic ERJ2BQFR56X); confirm in the P3768 schematic |

### Notes

- Without it the clock boots at a stale date (seen 2026-10-08: June 4) until NTP syncs. See the [time sync report](impl/reports/TIME-SYNC.md).
- Forum sources: [RTC battery on Orin Nano DevKit](https://forums.developer.nvidia.com/t/rtc-battery-on-jetson-orin-nano-developer-kit/296732), [How to add RTC battery](https://forums.developer.nvidia.com/t/how-to-add-rtc-battery-in-jetson-orin-nano/255792).
- A reported side effect: the battery lead and socket make the case cover sit unevenly.
- Polarity: one forum post says the positive pad is marked with a white triangle. Confirm with a meter before connecting.
- Test after fitting: power off fully, wait a few minutes, boot with no network, and check `cat /sys/class/rtc/rtc0/date` (should be today, not a reset date).
- Low priority: online almost always means NTP within a minute; the gap only matters for offline drives (see the [time sync report](impl/reports/TIME-SYNC.md)).