SwitchBlox – Small Ethernet Switch


The Small, Robust Ethernet Switch

  • Small Ethernet Switch for demanding applications.
  • Wide, protected input voltage range from 5 to 51V.
  • 5V, 1A auxilliary output onboard.
  • 5 port ethernet network switch works out the box.
  • 10/100MB Speed.
  • Auto MDI-X crossover.
  • All cables included.
  • ATtiny202 embedded onboard for custom firmware upload (currently a BETA feature).
  • PoE injector onboard (IEEE 802.3af compatible for PoE devices).

Available on back-order

SKU: BB-SWB-D-1 Category:


The Small, Robust Ethernet Switch


SwitchBlox is a small ethernet switch with five 10/100MB ports, specifically designed for space constrained and noisy environments.

With an overall size of 44.5mm (1.75 inches) by 44.5mm (1.75 inches), SwitchBlox is the smallest network switch in the world, making it perfect for robots, drones or any space limited networking application.

Plug and play network switch

As an unmanaged network switch it works straight out the box, all you need to do is…

  1. Apply a 5 to 51V DC supply.
  2. Connect your devices using the included cable set.
  3. It will automatically begin forwarding packets, no coding or setup needed.

Firmware for advanced switch behavior (BETA FEATURE!)

SwitchBlox requires no firmware to work, however we want to make it easy for uses to create customised switch behaviour. To do this we’ve embedded an ATtiny202 onto the board, that controls the onboard RTL8305 ethernet switch over an SMI interface.

The user can program the ATTiny202 over UPDI, which then configures the RTL8305 over SMI via its internal registers.

This feature is current in beta as we work on drivers to make this easy. If you want to contribute to this development, please get in touch!


We’ve squeezed all necessary Ethernet circuitry into SwitchBlox without making performance compromises. We use magnetics for improved signal integrity and electrical isolation between each ethernet bus.


We use Molex Picoblade connectors on all our boards to keep them tiny, and we include all the cables needed to get started, which are…

1 x SwitchBlox to SwitchBlox Coupler (Molex male to Molex male)

Use this cable to connect two SwitchBlox together to form a larger network.

5 x SwitchBlox RJ-45 Network Cables (Molex male to RJ-45)

Use this cable to connect any external ethernet device with a RJ-45 port.

2 x SwitchBlox Power Cables (Molex male to tinned wires)

Use this cable to connect a 5 – 51V DC power supply to power SwitchBlox.

Also use this cable to get a clean 5V, 1A supply from SwitchBlox to power external devices like Embedded Computers, Motor drivers or IP Cameras.

Ethernet Pinout

Below is a handy graphic that shows how we transition from a Molex Picoblade pinout to the standard RJ-45 ethernet cables. For 10/100 Mbps ethernet we use two differential channels, transmit and receive, for a total of four conductors.

PoE injection onboard (BETA FEATURE!)

We’ve added circuitry to SwitchBlox that allows you to selective injection voltage onto any combination of the ports, simply by toggling a DIP switch on the back.

In the off position, the ethernet port functions as a standard, AC coupled ethernet signal.

In the on position, the ethernet signal is shifted up by whatever the input voltage is to the board. Using an input voltage of 44V to 48V, makes this IEEE 802.3af PoE compatible, allowing you to power downstream devices directly from SwitchBlox!

Please note, due to the lack of standardization on PoE, we cannot guarantee this will work with all devices stated as PoE compatible. If in doubt, please consult the datasheet of your device and search specifically for “IEEE 802.3af”. If you’re unsure, feel free to get in touch.

Resources and links

Github Repo

Step file

Schematic PDF

Additional information

Additional information

Weight7 g
Dimensions135 × 90 × 65 mm
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