Radar Compatibility and connections clarification.

[Jetson Nano]

Hello @eric-katzfey @vinny,

I am planning to integrate a 60 GHz mmWave radar into my current VOXL 2-based system and would appreciate some guidance regarding the recommended interface, hardware compatibility, and software integration.

I am currently evaluating the following two radar options:

1. DesignCore RS-6843AOPU USB 60 GHz mmWave Radar Sensor — D3 Engineering
D3 Engineering RS-6843AOPU

2. Texas Instruments IWR6843AOPEVM — IWR6843AOP Evaluation Module
TI IWR6843AOPEVM

Both are based on the IWR6843AOP 60–64 GHz mmWave radar platform.

Current VOXL 2 configuration

My current system uses the J3 connector for my existing Doodle Labs and Flight Controller connections.

Since I am currently using the USB connection available on J3 for these existing connections, the UART and I²C interfaces are still available for my radar integration.

Therefore, I am considering using the J19 External Sensors connector, which provides UART and I²C interfaces, to connect the external radar while keeping my existing J3 configuration unchanged.

I would like to confirm whether this approach is feasible and which interface would be recommended for the radar.

UART

• Can the RS-6843AOPU or IWR6843AOPEVM be connected to VOXL 2 through one of the J19 UART interfaces?

• Which J19 UART would you recommend for a dedicated radar application?

• Are the J19 UARTs already assigned to any default VOXL 2 functionality, and can one be reassigned to a custom radar application?

• Are the UART voltage levels of both radar options compatible with the 3.3 V CMOS UART on VOXL 2?

• What baud rate and data protocol would you recommend for receiving processed radar data?

I²C

I am also considering using I²C instead of UART, particularly if I only need processed radar information such as range, radial velocity, angle, target information, or obstacle information.

• Can I use the VOXL 2 J19 I²C interface to connect either of these radar modules?

• Which J19 I²C bus would you recommend?

• Are either of the J19 I²C buses already reserved for other VOXL 2 peripherals/functions?

• Can a custom VOXL application directly access the J19 I²C bus?

• Is there an existing VOXL driver/API that can be used for a custom I²C radar device?

• Between UART and I²C, which would you recommend for radar integration considering bandwidth, latency, reliability, and software support?

USB

I would also like to understand the USB option.

• For the RS-6843AOPU, is USB the preferred interface for accessing its processed radar/algorithm output?

• For the IWR6843AOPEVM, can VOXL 2 receive the radar point-cloud data directly over USB?

• Given that my J3 USB connection is already being used, is there another recommended USB host interface/add-on for connecting the radar to VOXL 2?

Final recommendation

Before I start the integration, I would especially appreciate your recommendation on:

RS-6843AOPU vs. IWR6843AOPEVM

and

J19 UART vs. J19 I²C vs. USB

for the most reliable and maintainable VOXL 2 integration.

My main requirement is to keep my existing Doodle Labs and Flight Controller connections on J3 unchanged and use the remaining available VOXL 2 interfaces for the radar.

Any guidance on the recommended hardware connection, J19 pin/interface selection, voltage levels, and software integration path would be greatly appreciated.

Thank you!

[Eric Katzfey]

We don't have any experience with those radars so it's hard to make any kind of recommendation. PX4 has no native driver support for those so it's likely you would need to create your own SW to interface with the radars and process the incoming data. You could then generate Mavlink OBSTACLE_DISTANCE or DISTANCE_SENSOR messages to send to PX4. Codex recommends using only USB for these radars.

[Jetson Nano]

@eric-katzfey Thank you for getting back to me.

To clarify my setup:
I am replicating the RADVIO pipeline from NTNU using their ROS 1 codebase. The software messaging between PX4 and ROS is already sorted; my main challenge is finalizing the physical hardware interfaces on the VOXL 2.

Current Hardware Configuration:

J3 Port: Attached to a USB 3.0 / UART expansion board.

Expansion UART: Connected to FlightCore v2.

Expansion USB: Connected to a Doodle Labs mini radio.

Unused/Free Ports: J10, J18, and J19.

Key Questions:

1. Physical Port Mapping: Depending on how the radar needs to be interfaced, which specific headers/ports on VOXL 2 should be allocated for:

• list itemUSB: (If connecting via a USB interface)

• list itemUART: (If connecting via serial)

• list itemI2C: (If connecting via I2C)

2. Alternate UART Setup: If I disconnect the J3 expansion UART from the FlightCore v2 and instead route direct UART via J18 (for an FPV ESC), can the freed-up UART port on the J3 expansion board be safely reassigned to the radar?

3. Drivers & ROS 1 Integration: What is the recommended workflow or driver stack on VOXL 2 for bringing up radar serial/USB streams and exposing them to ROS 1 nodes?

Any advice on the optimal pinout and hardware topology for this build would be greatly appreciated!