> For the complete documentation index, see [llms.txt](https://docs.arkelectron.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.arkelectron.com/products/sensor/ark-mag/hardware.md).

# Hardware Reference

## Specifications

| Specification | Value                                                     |
| ------------- | --------------------------------------------------------- |
| Magnetometer  | [PNI RM3100](https://www.pnisensor.com/rm3100/), tri-axis |
| MCU           | STM32F412VG                                               |
| CAN           | 2× Pixhawk-standard 4-pin JST-GH                          |
| Debug         | Pixhawk-standard 6-pin JST-SH                             |
| Power         | 5 V, 44 mA average, 50 mA max                             |
| Dimensions    | 2.7 × 1.8 × 0.9 cm                                        |
| Weight        | 3 g                                                       |

## Pinout

### CAN (×2) — 4-pin JST-GH

| Pin | Signal | Voltage |
| --- | ------ | ------- |
| 1   | 5V     | 5.0 V   |
| 2   | CAN\_P | 5.0 V   |
| 3   | CAN\_N | 5.0 V   |
| 4   | GND    | GND     |

### Debug — 6-pin JST-SH

| Pin | Signal     | Voltage |
| --- | ---------- | ------- |
| 1   | 3.3V       | 3.3 V   |
| 2   | USART2\_TX | 3.3 V   |
| 3   | USART2\_RX | 3.3 V   |
| 4   | FMU\_SWDIO | 3.3 V   |
| 5   | FMU\_SWCLK | 3.3 V   |
| 6   | GND        | GND     |

## LEDs

| Status LED                          | Meaning                                                                                                                                                                                                       |
| ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Green, fast blink (10 Hz)           | Node firmware running. It does not change with CAN traffic.                                                                                                                                                   |
| Green, slow blink (1 Hz)            | Bootloader listening for CAN traffic                                                                                                                                                                          |
| Blue, blinking (2 Hz)               | Bootloader waiting for a node ID from the flight controller                                                                                                                                                   |
| Blue and green, blinking (3 Hz)     | Bootloader waiting up to 3 s for the flight controller to start a firmware update                                                                                                                             |
| Red, green and blue together (3 Hz) | Firmware update in progress                                                                                                                                                                                   |
| Red, blinking                       | Firmware update error. 1 Hz: the flight controller returned a file error. 2 Hz: the flight controller stopped responding. 4 Hz: the image failed its CRC check. A failed update restarts the node after 20 s. |

Without valid firmware the node stays in the bootloader until the flight controller flashes it.

## Wiring

The ARK MAG is connected to the CAN bus using a Pixhawk standard 4 pin JST-GH cable. For more information, refer to the [CAN Wiring](https://docs.px4.io/main/en/can/#wiring) instructions.

Multiple sensors can be connected by plugging additional sensors into the ARK MAG’s second CAN connector.

## 3D Model and Case

| File                                                                                                                    | Contents       |
| ----------------------------------------------------------------------------------------------------------------------- | -------------- |
| [ARK\_MAG\_Rev\_1\_0.step](https://github.com/ARK-Electronics/ark-hardware/raw/main/ARK_MAG/model/ARK_MAG_Rev_1_0.step) | Board, rev 1.0 |
| [Top\_Case.stl](https://github.com/ARK-Electronics/ark-hardware/raw/main/ARK_MAG/case/Top_Case.stl)                     | Case top       |
| [Bottom\_Case.stl](https://github.com/ARK-Electronics/ark-hardware/raw/main/ARK_MAG/case/Bottom_Case.stl)               | Case bottom    |

All files: [ARK\_MAG in ark-hardware](https://github.com/ARK-Electronics/ark-hardware/tree/main/ARK_MAG)


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