Real-Time HAT

Real-Time Communication with the Raspberry PI
Available October 2020

Unleash the power of industrial Ethernet protocols on a Raspberry PI !


  • Precise network timing, for real time protocols such as Time-Sensitive Networking (TSN)
  • Synchronization between HATs, over the network, or with external GPS PPS
  • Stackable: allows for additional HATs attached on top
  • Simple configuration and use


  • Time-Triggered Transmission/Buffers (10/100/1000 Mbps)
  • Hardware-timestamping of all incoming and all marked outgoing frames
  • Nanosecond-scale hardware clock: time synchronization with PTP/AS(REV) using Linux-PTP
  • Simple synchronization with PPS connector (master or slave)
  • Enable hardware-accuracy in Linux kernel 5.4+ TSN
  • YANG Data Model of the RealTimeHAT for NetConf (Qcp)
  • Hardware statistics with software-based aggregation
  • Timestamp injection mode: inject timestamp into certain frames to collect precise path delays
  • Raspberry PI 4 already officially supported, Raspberry PI 3 supported soon
  • Display/Camera/PoE HATs officially supported
  •  2/3 x 100/1000 Mbps (full speed available @ Raspberry PI)

Use cases

  • Linux-TSN Raspberry PI endpoint with high precision to inject precisely scheduled Ethernet traffic in a TSN Network
  • Connect non-deterministic Ethernet services to real-time networks
  • Time-accurate network device testing
  • FPGA-based network TAP, transparent forwarding statistics, with fixed latency, suitable for real-time networks

example figure


TSN with the Raspberry PI

Video coming soon…

Time-sensitive network analysis with the Raspberry PI

Video coming soon…


CONTACT US for custom versions, e.g., with automotive Ethernet PHYs & connectors, custom TSN features (FPGA+Software), TSN-lab bundles (TrustNode switch + Raspberry’s + HAT’s)

2 Port-specific Extended Features

Raspberry PI Ethernet connected to one HAT port, the other HAT port connected to network (may connect to PoE HAT)

  • Features
    • MAC + VLAN + IP based stream classification
    • Qbv + Qci in hardware, Qcc in software
  • Use Case:
    • TSN endpoint
    • Simple Real-time endpoint

3 Port-specific Extended Features

Raspberry PI Ethernet connected to one HAT port, other two HAT ports connected to network (one of them may connect to PoE HAT)

  • Features:
    • MAC + VLAN + IP based stream classification
    • Qbv+Qci in hardware, Qcc in software
  • Use Cases:
    • Switched TSN endpoint
    • Real-time endpoint, e.g., Profinet
    • Transparent real-time TAP, for traffic monitoring or timestamp injection
    • Real-time Traffic Generator/Analyzer (Device under Test (DUT) testing)
    • Legacy-to-TSN bridging (Qbv and Qci)

Questions & Answers


The standard Raspberry PI network interface does not provide:

  • precise or accurate timestamping
  • precise or accurate transmission times or rate shaping

InnoRoute has a competitive TSN implementation for FPGAs, used in its TrustNode switches/routers, and experience in real-time networking.
The Raspberry PI is a widely used and easy to use open-source platform: why don't you use it for accurate network testing on a budget, to avoid expensive specialized hardware?

Is this just another SPI network card for the Raspberry PI?

No, SPI is just used only for configuration, while packets/frames are forwarded only through Ethernet ports.

Will the Raspberry PI 3 be supported?

For the TSN features, InnoRoute provides patches to the network driver of the Raspberry PI 4. For the Raspberry PI 3 the same changes need to be applied. So InnoRoute started with the Raspberry PI 4 and supports the Raspberry PI 3 at a later point in time. In the meantime, you are free to use the code in our git repository and adapt it to other platforms. (You are welcome to create pull requests to share your code with other users 🙂 )

What is the throughput of the HAT?

The HAT provides line-rate forwarding at the selected speed (10/100/1000 Mbps per port). Forwarding is limited just by the Raspberry PI's Ethernet interface:

  • Raspberry PI 4: 1 Gbps
  • Raspberry PI 3b+ and below: throughput is limited by the USB network interface of the Raspberry PI mainboard, but the HAT supports Gigabit line-speed, which is important, e.g., for time-triggered transmission

Does the PoE HAT work with the Real-Time-HAT?

Yes, the Real-Time HAT connects one of its ports to a HAT above using the standard 4 PoE-Pins, so the PoE HAT fits on top.


Request offer

    TSN endpointTSN testerNetwork AnalyzerTraffic GeneratorFPGA dev. boardother:

     If don't receive a confirmation E-Mail please contact or +49 89 87767567


    InnoRoute does not guarantee fitness of the device for a specific purpose. The product description may change without prior notice.