ESP32

What it is

It is a hardware host. What it does in a smart home depends on the firmware: Espressif's SDKs, ESPHome or Tasmota.[1]

The family splits by radio. The original ESP32 and the S-series have Wi-Fi and Bluetooth. ESP32-C6 adds Wi-Fi 6 and an IEEE 802.15.4 radio for Thread and Zigbee. ESP32-H2 has 802.15.4 and Bluetooth LE but no Wi-Fi, so Espressif pairs it with a Wi-Fi chip to build border routers and bridges.[1][5][6]

Which paths it supports

Espressif's ESP-Matter SDK is built on the open-source Matter SDK. It makes Matter over Wi-Fi devices on ESP32, C-series and S-series chips, and Matter over Thread devices on the H-series, C5 and C6. It also covers Thread border routers and Matter bridges for Zigbee and BLE Mesh devices.[2]

The ESP Thread Border Router SDK is Thread 1.4 certified. Its reference board pairs an ESP32-S3 host with an ESP32-H2 radio co-processor. The ESP Zigbee SDK runs on ESP32-H2 and ESP32-C6 as a coordinator, router or end device, to Zigbee 3.0 and Zigbee PRO R23.[3][4][8]

Flashed with ESPHome, an ESP32 can also be a Bluetooth proxy that extends Home Assistant's BLE reach.[9]

Local or cloud

Matter, Thread and Zigbee built on these SDKs run on the local network. Whether a finished product uses a cloud service is the maker's choice.[2][3]

Limitations

• Only chips with an 802.15.4 radio (H-series, C5, C6) can join Thread or Zigbee. The original ESP32 cannot.[2][5][6]
• ESP32-H2 has no Wi-Fi, so a border router or bridge built on it needs a second, Wi-Fi-capable Espressif chip.[6]