Mercury M301
Hardware is similar TP-Link TL-MR3040 v1, but intended for PRC.
A portable router with an onboard 2000mAh rechargeable_battery. It provides 150MBit/s 802.11bgn wireless connectivity, one Fast Ethernet port as well as two USB ports (of which one only offers power but no data connection).
Note: Many of these routers are marketed as a “3G travel router” but none actually include a 3G modem - the marketing term rather means that the OEM firmware supports a certain range of USB 3G/4G modems because it contains the drivers! Ignore that, because with OpenWrt ANY router with USB supports 3G hardware... 
M301 and TL-MR3040 differences
Althought M301 and MR3040 seem similar on the outside, there are differences:
- M301 is chinese only
- Case slightly different
- Only one bi-color LED:
- green under GPIO control
- red indicates battery low, or charging in progress
Supported Versions
Hardware Highlights
- SoC: Atheros AR9331 rev1
- 802.11 b/g/n 150Mbps
- Powered via mini-USB (5V) or Li-ion Battery included (3-4 hours)
- Only 94g
Installation
Method Using Web GUI (Recommended)
As with most TP-Link Routers this one can be flashed using the TP-Link Webinterface.
- Connect to the M301 router via Ethernet cable at IP address 192.168.1.1
- login to the router's web GUI (default login/password: admin / admin)
- overwrite the factory firmware by installing the openwrt-ar71xx-generic-tl-mr3040-v1-squashfs-factory.bin like a regular firmware update.
- Wait for the progress bar to finish twice (the device will reset itself in the process)
- proceed with basic configuration as with any fresh OpenWrt install.
Note that some software uses 192.168.0.1 and some software uses 192.168.1.1.
LEDs
How to configure LEDs in general, see the LED section in the led_configuration.
The M301 has 1 bi-color LED:
| LED name | LED color | LED print | Internal name | Trigger |
|---|---|---|---|---|
| LED | Red | N/A (fixed supply) | N/A | |
| LED | Green | tp-link:green:3g |