Xiaomi MiWiFi 3G v2

multiple revisions of this device, use caution

abgn+ac (AC1200)
Xiaomi MiWiFi 3G
3rd Party Firmware
dd-wrt	Status Unknown
OpenWrt	Supported
Tomato any flavor	Incompatible
Gargoyle	Status Unknown
Platform
Brand • Model • Rev	Xiaomi MiWiFi 3G v2
FCC ID	none specified
Type	wireless router
CPU1 Y	MediaTek MT7621A
CPU1 Type	MIPS 1004Kc
CPU1 Speed	880 MHz ( 2 cores ) 16-bit
Flash1 Chip	GigaDevice GD25Q128B
Flash1 Size	16 MiB 16,777,216 B <br />131,072 Kib <br />16,384 KiB <br />128 Mib <br />0.0156 GiB <br /> (SPI NOR)
RAM1 Size	128 MiB 134,217,728 B <br />1,048,576 Kib <br />131,072 KiB <br />1,024 Mib <br />0.125 GiB <br /> (DDR3)
RAM1 Chip	ESMT M15T1G1664A
ETH chip1	MediaTek MT7621A
Switch	MediaTek MT7621A
Ethernet Port Count	1-1GbE-WAN 2-1GbE-LAN
Wired Standard	IEEE 802.3i/3u/3ab
802dot11 OUI: none specified
Stock bootloader	U-Boot
Expansion IF types	none specified
Serial Port (UART)	yes, 3.3V TTL, (115200 8N1)
Other
3rd Party Firmware Support	OpenWrt • (List | Dev | DLs)
Radio 1
Chip1	MediaTek MT7603E
Wireless interface OUI	none specified
Antenna Connector Type	none specified
MIMO status	2x2:2
Wireless Standard	IEEE 802.11b/g/n
802.11n	up to 300 Mbps
802.11g	up to 54 Mbps
802.11b	up to 11 Mbps
WiFi Operating Frequency	2.4 GHz
Radio 2
Chip1	MediaTek MT7612E
Wireless interface OUI	none specified
Antenna Connector Type	none specified
MIMO status	2x2:2
Wireless Standard	IEEE 802.11a/n/ac
802.11ac	up to 867 Mbps
802.11n	up to 300 Mbps
802.11a	up to 54 Mbps
WiFi Operating Frequency	5 GHz
CPU1 brand Radio1 chip1 brand Radio2 chip1 brand Xiaomi MiWiFi (R1D) Broadcom Broadcom Broadcom Xiaomi MiWiFi (R2D) Broadcom Broadcom Broadcom Xiaomi MiWiFi 3G (R3G) MediaTek MediaTek MediaTek Xiaomi MiWiFi 3G v2 MediaTek MediaTek MediaTek Xiaomi MiWiFi Nano (R1CL) MediaTek MediaTek

For a list of all currently documented MediaTek chipsets with specifications, see MediaTek.

For a list of all currently documented Xiaomi devices with specifications, see Xiaomi.

• 300 Mbps - 2SS 2.4GHz 802.11n (40MHz chan.),

• 867 Mbps - 2SS 5GHz 802.11ac (80MHz chan.) = AC1200 class

Flashing

Flashing OpenWrt

On the OpenWrt ToH (techdata entry)
On the OpenWrt Wiki
On the OpenWrt Forum
On the OpenWrt Forum

Target: ramips
Subtarget: mt7621
Package architecture: mipsel_24kc
Supported Since Commit
Support started version: 21.02.0
Current supported version: 25.12.2

LAN Hardware: MediaTek MT7621
WLAN Hardware: MediaTek MT7603E, MediaTek MT7612E
Installation method(s):
U-Boot TFTP + serial recovery, see git-commit
Recovery method(s):
U-Boot TFTP + serial recovery
Comment:
Xiaomi 3G v2 is also sold as '4A Gigabit'

git • >>

ramips: add support for Xiaomi Mi Wi-Fi Router 3G v2 - CMIIT ID: 2019AP2581 - SoC: MediaTek MT7621 - Flash: 16MiB NOR SPI (GigaDevice GD25Q128B) - RAM: 128MiB DDR3 (ESMT M15T1G1664A) - Serial: As marked on PCB, 3V3 logic, baudrate is 115200, 8n1 - Ethernet: 3x 10/100/1000 Mbps (switched, 2xLAN + WAN) - WIFI0: MT7603E 2.4GHz 802.11b/g/n - WIFI1: MT7612E 5GHz 802.11ac - Antennas: 4x external (2 per radio), non-detachable - LEDs: Programmable "power" LED (two-coloured, yellow/blue) Non-programmable "internet" LED (shows WAN activity) - Buttons: Reset INSTALLATION: Bootloader won't accept any serial input unless "boot_wait" u-boot environment variable is changed to "on". Vendor firmware (looks like an illegal OpenWrt fork) won't accept any serial input unless "uart_en" is set to "1". Tricks to force u-boot to use default environment do not help as it's restricted in the same way. With bootloader unlocked the easiest way would be to TFTP the sysupgrade image or to sysupgrade after loading an initramfs one. For porting the flash contents were changed externally with an SPI programmer (after lifting Vcc flash IC pin away from the PCB). Forum thread [0] indicates that this device is identical to "Xiaomi Mi Router 4A Gigabit Edition". [0] https://forum.openwrt.org/t/xiaomi-mi-router-4a-gigabit-edition-r4ag-r4a-gigabit-fully-supported-but-requires-overwriting-spi-flash-with-programmer/36685