# 2. Hardware Reference

### 2.1 Operational Temperatures

The following operating temperature ranges apply to the standard DCS2 Default kit components:

| Component                | Min    | Max    |
| ------------------------ | ------ | ------ |
| DCS2 Carrier Board (PCB) | −40 °C | 85 °C  |
| Jetson Orin NX SoM       | −25 °C | 105 °C |
| CubePilot Cube Orange+   | −10 °C | 55 °C  |

{% hint style="info" %}
**Note:**

The system-level operational temperature is constrained by the most limiting component, which is the Cube Orange+ at −10 °C minimum.
{% endhint %}

***

### 2.2 Power System

Key ratings for the DCS2.PDB\_Default:

| Parameter                               | Value                                                |
| --------------------------------------- | ---------------------------------------------------- |
| VDD MAIN input voltage range            | 6 V – 26.5 V (recommended 9 – 26.5 V)                |
| VDD MAIN max continuous current         | 50 A (including ESC pads)                            |
| ESC pads (ESC1–4) total continuous      | 45 A                                                 |
| VDD SWITCHED output voltage             | Same as VDD MAIN (no regulation); no current limiter |
| On-board current sensor range (CAN2)    | Up to 55 A measured and reported via DroneCAN        |
| Peak theoretical system power (no ESCs) | \~100 W                                              |
| Onboard PDB CAN bus for battery data    | CAN2 — uavcan.equipment.power.BatteryInfo            |
| UBEC input for high-voltage batteries   | Step down to 9.2 V before VDD MAIN when using >14S   |

{% hint style="info" %}
**Note:**

VDD SWITCHED pads can power external components; output voltage equals VDD MAIN voltage. There is no current limiter on VDD SWITCHED — do not short these pads.
{% endhint %}

***

### 2.3 Ethernet Port

The DCS2 Pilot board exposes three Ethernet interfaces via FFC/ZIF connectors. The magnetics (transformer) are located on the small RJ45 breakout adapter, not on the Pilot board itself. The board-to-cable connection is an FFC ribbon cable.

FFC Cable Handling Guidelines:

* Always open the black ZIF latch fully before inserting or removing the ribbon cable
* Never pull the cable out while the latch is closed — this is the leading cause of pin damage
* After insertion, close the latch firmly; some mechanical play is normal and does not indicate a loose connection
* For vibration-prone airframe installations, mechanically secure both ends of the cable to prevent tension on the connector pins
* The Livox Mid-360 LiDAR is electrically compatible — connect to GBE\_M0 and GBE\_M1 pins only

***

### 2.4 GPIO Expander — GPIO\_EXP4 and GPIO\_EXP5

The DCS2 Adapter Default board exposes two user-accessible GPIOs from a TCA6408A I2C expander (I2C address 0x20, bus 1).

| Label      | gpiochip  | GPIO line | Notes                                         |
| ---------- | --------- | --------- | --------------------------------------------- |
| GPIO\_EXP4 | gpiochip2 | GPIO 312  | User accessible, 3.3 V, 100 Ω series resistor |
| GPIO\_EXP5 | gpiochip2 | GPIO 313  | User accessible, 3.3 V, 100 Ω series resistor |

GPIOs 308–311 on gpiochip2 are reserved (CSI connectors and future use). At power-on, all expander I/Os are configured as inputs.

To list all GPIOs and verify the expander is detected:

```
cat /sys/kernel/debug/gpio
```

To control a pin using the sysfs interface (example: set GPIO\_EXP4 high):

```
echo 312 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio312/direction
echo 1 > /sys/class/gpio/gpio312/value
```

Alternatively, use libgpiod (gpioset, gpioget) for command-line access.

{% hint style="info" %}
**Note:**

For additional GPIOs beyond EXP4/5, connect an I2C GPIO expander to the GPS\_JET connector (I2C0 from Jetson). The default adapter board provides no other Jetson GPIO breakout.
{% endhint %}

***

### 2.5 RTC (Real-Time Clock)

The DCS2 Pilot board includes a coin-cell battery that provides RTC backup power, charged by the 3.3 V rail when the system is running. On DCS1.2 two RTC devices are visible:

* /dev/rtc0 — Hardware RTC backed by the coin cell
* /dev/rtc1 — Virtual RTC (always initialises at 1970-01-01 00:00:00 UTC)

The system service rtc\_sync.service runs /usr/local/bin/rtc\_sync.sh on boot and uses /dev/rtc0. Verify by checking:

```
sudo hwclock --rtc=/dev/rtc0 -r
timedatectl
```

To manually set the hardware RTC:

```
sudo hwclock --set --rtc=/dev/rtc0 --date="2025-11-28 12:00:00"
sudo hwclock --rtc=/dev/rtc0 -w
```

{% hint style="info" %}
**Note:**

The coin-cell RTC on DCS1.2 boards retains time for only a few days when fully discharged. Newer DCS2 revisions include a more efficient RTC circuit with longer retention.
{% endhint %}

For GPS-based time synchronisation: GPS data arrives at the Jetson through the Cube via MAVLink (GPS2 port is wired to the Cube, not Jetson directly). Install mavlink-router, connect a MAVLink client, and read SYSTEM\_TIME messages from the Cube. Write the GPS-derived time to /dev/rtc0 using hwclock or a custom Python script via pymavlink.

***

### 2.6 WiFi and Bluetooth Module

The Pilot board integrates a Sparklan WNSQ-261ACN(BT) module, which provides both IEEE 802.11ac Wi-Fi and Bluetooth 5 on a single chip. No separate Bluetooth module is required. Refer to the Sparklan datasheet for antenna specifications when selecting replacement or external antennas (MHF4 connector, 2.4 GHz).

***

### 2.7 HDMI Output

The DCS2.Pilot board exposes a micro-HDMI connector. A micro-HDMI to full-size HDMI adapter cable is included in the standard accessory set. USB-C to HDMI/DisplayPort conversion is not supported — the Jetson Orin NX SoM does not implement DisplayPort Alt Mode over USB-C without an external bridge chip.

***

### 2.8 Audio

I2S audio is not routed to any connector on the DCS2 Adapter Default board. For audio output, use a USB audio adapter. The USB-A ports on the adapter board can supply the necessary 5 V.

***

### 2.9 Fan Connector

The fan connector on the Pilot board operates at 5 V. PWM and TACH signals are also at 5 V logic level. If you need to power a 12 V fan, use a separate 12 V supply for the fan motor and connect only the PWM, TACH, and GND signals from the board connector.


---

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