From DD-WRT Wiki
The Frys FR-300RTR is basically a rebranded D-Link DIR-615 E1, except for $30. As of this writing, the only hardware version is A1, and firmware version is 1.00. Luckily, it completely supports the DIR-615 E1 firmware.
The factory default IP for this router is 192.168.0.1, user is "admin", password is blank.
 Pros of this hardware
- 4 MB of flash memory
- 32MB of RAM
- 400mhz CPU
- Very cheap ($30)
- 2009 hardware, available in most Fry's Electronics
- Pretty easy to flash to DD-WRT
- Surprisingly decent built-in firmware for something made by Fry's
 Cons of this hardware
- No USB port, so no Printer Sharing or hard drive expansion.
- It's $30. Who knows how long it'll last?
 Installation Instructions
Unlike the D-Link routers, you cannot flash the FR-300RTR through the normal Frys web interface. Instead, you have to use the "Emergency Room" web interface, which is fairly easy to get to.
 Where to download the firmware
A known working version of BrainSlayer's build of DD-WRT is located here: ftp://dd-wrt.com/others/eko/BrainSlayer-V24-preSP2/07-16-10-r14815/dlink-dir615e1/. Download the dir615e1-factory-to-ddwrt-firmware.bin file to flash from factory to standard.
 Firmware Update/Emergency Room Flashing Guide
- Plug your computer into one of the LAN ports on the router, and set your IP to something in the 192.168.0.X range. Make sure the router is unplugged, too.
- Push in the Reset button on the device, and, while keeping it pushed in, plug in the power cable. Keep the reset button pushed in until the Status LED stops blinking and becomes a solid, constant green.
- Other people have reported that, instead of the above, they have to: "keep holding reset button down until you note a 'short' duration where the light winks out and then comes back on (shorter than the approximately 1 second per blink, and this only happens once) and then continues on to blink at about 1 per second". Thanks to rkg22 for this!
- Open a web browser and go to http://192.168.0.1/. On the screen that's presented, go to choose file, and select the "dir615e1-factory-to-ddwrt-firmware.bin" from wherever you saved it to. Click "Send" to begin uploading.
- The firmware should be uploaded, and the web page will change to a percentage counter showing the percent completed with the firmware upgrade. DO NOT UNPLUG YOUR ROUTER OR NAVIGATE AWAY!
- If you do not see this page, look at "troubleshooting" below.
- The percentage number should get to 100%, and the process will be complete. If you look at the front of the router, the Power LED should be on, and the Status LED should be completely off (not blinking!). This means DD-WRT is installed!
- Change your computer's IP address to something in the 192.168.1.X range.
- In your web browser, go to http://192.168.1.1/ - DD-WRT should load, and you're done! Feel free to configure it to your whims and delights now.
- If you click "Send" to upload the firmware, and either nothing happens (the page does not change to the percentage counter), it says the firmware/hardware is invalid, or the connection is reset, you need to use a different browser! I tried this with Chrome on Windows 7, and it didn't work, but Firefox 3.6.6 worked fine.
 LED Lighting Information
 Default/Stock Firmware
Using the default Fry's firmware, the Power LED should remain constantly on, the Status LED should blink steadily when working, and the Internet, Wireless, and LAN LEDs should blink based on activity. Whichever LAN ports are plugged in stay on when no activity is present.
 Firmware Update/Emergency Room
When in "Emergency Room" mode, the Power LED should remain constantly on, the Status LED should also remain constantly on, and whichever LAN ports are plugged in will be on.
 DD-WRT Firmware
Once DD-WRT is flashed, the Power LED should remain constantly on, the Status LED will never be on, and the Internet, Wireless, and LAN LEDs will blink with activity. Whichever LAN ports are plugged in stay on when no activity is present.