> 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/flight-controller/ark-pi6x-flow/hardware.md).
# Hardware Reference
## Specifications
| Specification | Value |
| -------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- |
| Flight controller | ARKV6X: [STM32H743](https://www.st.com/en/microcontrollers-microprocessors/stm32h743ii.html), 480 MHz, 2 MB flash, 1 MB RAM |
| IMUs | Dual [Invensense ICM-42688-P](https://invensense.tdk.com/products/motion-tracking/6-axis/icm-42688-p/), heated |
| Barometer | [Bosch BMP390](https://www.bosch-sensortec.com/products/environmental-sensors/pressure-sensors/bmp390/) |
| Magnetometer | [ST IIS2MDC](https://www.st.com/en/mems-and-sensors/iis2mdc.html) |
| Power monitor | [TI INA226](https://www.ti.com/product/INA226) voltage and current monitor |
| Optical flow (Pi6X Flow only) | [PixArt PAW3902](https://www.pixart.com/products-detail/93/PAW3902JF-TXQT) |
| Distance sensor (Pi6X Flow only) | [Broadcom AFBR-S50LV85D](https://www.broadcom.com/products/optical-sensors/time-of-flight-3d-sensors/afbr-s50lv85d), 30 m. Not supported in ArduPilot |
| Compute module | Raspberry Pi Compute Module 4; CM4 Lite boots from the microSD slot. Compute Module 5 with the [differences below](#compute-module-5) |
| Flight controller interfaces | TELEM1, RC input, 8 PWM outputs (DShot capable), UART4, GPS (UART, I2C), CAN, buzzer, debug (SWD, UART console), microSD |
| Pi interfaces | Micro HDMI, Ethernet, USB-C host, 2× USB JST-GH, 2× MIPI CSI (22-pin FFC), programming micro USB, I2C, UART, LED strip GPIO, GPIO, console, CPU fan |
| Power | 5.5–25.2 V (2S–6S) battery input |
| ESC mounting | 4-in-1 ESC, 30 × 30 mm |
| Dimensions | 91.5 × 56 mm, without compute module and ESC |
| Weight | 41 g without compute module, SD card and ESC; 53 g with CM4 and SD card |
## Compute Module 5
The board was designed for the CM4. With a CM5:
| | CM4 | CM5 |
| ------------------------------- | --------------------- | ---------------------------------------------------------------------------------- |
| Telem2 to the flight controller | UART4, `/dev/ttyAMA4` | UART3, `/dev/ttyAMA3` |
| Pi UART3 connector | UART3, `/dev/ttyAMA3` | UART2, `/dev/ttyAMA2` |
| Cameras | CAM0 and CAM1 | CAM1 only, as `cam0` in `config.txt`. The CM5 uses the CM4's CAM0 pins for USB 3.0 |
| USB 3.0 | None | Not wired to any connector |
The `config.txt` for each module is in [After Flashing, Before Installing](/products/flight-controller/ark-pi6x-flow/flashing-guide/after-flashing-before-installing.md).
## USB
The compute module's USB 2.0 port goes through a mux to either the programming micro USB or an onboard USB hub. The hub feeds the flight controller, the USB-C port and both USB JST-GH ports.
{% hint style="warning" %}
The hub is full speed only (12 Mbps, USB 1.1) with either compute module, so every device behind it is limited to 12 Mbps.
{% endhint %}
While a cable is plugged into the micro USB, the compute module switches to that port and the hub is disconnected. Reboot after unplugging it.
## Pinout
{% file src="/files/dY8n9uZh7PYfBWbbkrNn" %}
## 3D Model and Case
| File | Contents |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------ |
| [ARK-Pi6X-Flow-Rev-2.0.step](https://github.com/ARK-Electronics/ark-hardware/raw/main/ARK_Pi6X/model/ARK-Pi6X-Flow-Rev-2.0.step) | Board model |
| [ARK-Pi6X-Flow-Rev-2.0-with-Sensor-FOV.step](https://github.com/ARK-Electronics/ark-hardware/raw/main/ARK_Pi6X/model/ARK-Pi6X-Flow-Rev-2.0-with-Sensor-FOV.step) | Board model with the flow and distance sensor fields of view |
All files: [ARK\_Pi6X in ark-hardware](https://github.com/ARK-Electronics/ark-hardware/tree/main/ARK_Pi6X)
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