busware

TUL TUL

TUL32: KNX TP interface for USB and Wi-Fi (ESP32-C6 + NCN5130), Ethernet via expansion board; with the KNX/IP firmware a KNXnet/IP gateway.

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TUL32 — KNX TP interface for USB and Wi-Fi

TUL32, board revision V3.5: USB-C receptacle and ESP32-C6-MINI-1 module at one end, the KNX bus terminal at the other

General

The TUL32 connects a KNX TP bus to a computer via USB, or to an IP network via Wi-Fi; Ethernet is available through an expansion board. What it does is decided by the firmware you install — it ships without firmware, and as delivered it does not transmit. It is a bare circuit board without enclosure, meant for DIY use. It replaces the old ATmega-based TUL stick.

What ships today is the ESP32-C6 version. Against the earlier ESP32-C3 it adds Wi-Fi 6 and, more to the point, an IEEE 802.15.4 radio — the one that makes Thread and Zigbee, and with them Matter over Thread, possible on this stick at all.

The ESP32-C6-MINI-1 module next to the USB-C receptacle; the KNX bus terminal sits at the opposite end

Specs

From the datasheet (Rev. 1.0):

Firmware

Every variant is flashed from the browser (Chrome, Edge or Opera — they support Web Serial) — no toolchain, no installation. The installer detects whether it is talking to a C3 or a C6 and writes the matching build. (Variants and chips below are what the live installer manifests listed on 2026-08-29.)

KNX/IP tunnel — the straightforward one

A UDP tunnel device, which is what Home Assistant and the usual tools expect. Thanks to the OpenKNX stack no separate knxd installation is needed. Runs on C3 and C6.

KNX-TP ↔ TCP bridge (cdc2net)

The transparent bridge: raw TP-UART over TCP, with no USB host involved. Wi-Fi is set up right after flashing over Improv. Runs on C3 and C6.

USB serial emulation

The raw path, for your own software. Runs on C3 and C6.

KNX commissioning over MCP

Turns the TUL into a KNX interface an agent can commission through, not just talk across: it assigns individual addresses, reads and writes device memory and properties, drives the load state machines and installs address and association tables — the connection-oriented management services ETS itself uses — and publishes to MQTT with Home Assistant discovery. The stick answers MCP on your LAN directly.

MQTT and Matter for TUL

MQTT for TUL and Matter for TUL are offered in the installer as well, but their manifests currently carry an ESP32-C3 build only — so they do not apply to a C6 stick as it ships today.

Documents

Datasheet and operating instructions for the TUL32 (article no. TUL32-OEM, board revision V3.5), Rev. 1.0 of 2026-09-25:

Further references:

Implementations / references

Availability

This unit is available in our shop.