ZBM-MG21 / ZBM-MG24
ZBM-MG21 and ZBM-MG24 are Inswift USB coordinators. Home Assistant, especially ZHA, often recognizes them as soon as they are plugged in. Factory firmware is usually EmberZNet NCP / EZSP. Reflash with the USB dongle model flasher.
Firmware
| Firmware | MG21 | MG24 |
|---|---|---|
| Zigbee coordinator | Yes | Yes |
| Zigbee router | Yes | Yes |
| Thread | Yes | Yes |
| MultiPAN (Zigbee + Thread together) | No | Yes |
Matter over Thread uses the Thread image on either stick; pick MG24 if you need Zigbee and Thread at the same time.
Silicon
| Item | EFR32MG21 | EFR32MG24 |
|---|---|---|
| Core | ARM Cortex-M33, up to 80 MHz | ARM Cortex-M33, up to 78 MHz |
| Flash | up to 1024 kB | up to 1536 kB |
| RAM | up to 96 kB | up to 256 kB |
| Radio | 2.4 GHz, TX up to about 20 dBm | 2.4 GHz, TX up to about 19.5 dBm |
MG24’s headroom is memory: about 1.5× flash and 2.5× RAM, which helps larger meshes and heavier stacks.
USB serial
| Model | Chip | USB serial |
|---|---|---|
| ZBM-MG21 | EFR32MG21 | CH9102 |
| ZBM-MG24 | EFR32MG24 | CP210x |
| ZBT-1P | EFR32MG21 | CP2102N |
ZBT-1P is also MG21, with official SkyConnect firmware and a CP2102N. Windows and macOS need the matching USB driver.
Which to pick
- ZBM-MG21: everyday Zigbee, or Thread on its own
- ZBM-MG24: more devices, more RAM, or MultiPAN (Zigbee + Thread together)
- ZBT-1P: to match the official ZBT-1 shape and SkyConnect firmware, see ZBT-1P
Do not plug straight into a PC rear USB port. Use a USB extension of 50 cm or more, and keep clear of routers and USB 3.0 enclosures.