The following environment variables can be supplied to go when compiling a program written in go for the GL-AR750s.

export GOARCH=mips
export GOMIPS=softfloat

On its own mips will fail with an Illegal Instruction error when running on the GL-AR750s and the reason is due to the GL-AR750s not having an FPU such that the GOMIPS=softfloat must be provided as well.

The following is a modification that draws out the RX, TX and GND pins of an GL-AR750s to the exterior of the casing making it available for any standard three pin connector to interface with the on-board serial port within the router.

The modification is easy to accomplish but requires some soldering in order to connect the pins of the connector to the router motherboard as well as a Dremel to cut an appropriately sized hole within the casing.

The GL-AR750s also provides a pin yet it has been left out because it is unsuitable to provide power to the serial port. Nevertheless, the GL-AR750s motherboard also provides I2C pins along with the serial pins such that perhaps a second connector could be fitted on top for the I2C.

Here is the full firmware update chain that has to be used to ensure that the GL-AR750s is properly updated:

• 3.104
• 3.105 (important)
• 3.216
• 4.318 (latest)
• latest OpenWRT

Just like any other radio equipment, the 30/70 rule applies and whilst the GL-AR750s is great at providing the 30% the rest of 70%, in the default format of the router, is provided by two meager little patch antennas on the side of the router.

Portability was clearly in mind when designing the two small antennas but if you're willing to carry two small anetnna cables and two additional antennas, then there is a better solution that will additionally provide a whole lot of range compared to the two built-n antennas.

Fortunately, the two provided antennas are just some plastic bits that can be pulled out, and then two RP-SMA to IPX antennas can be added to the case, both on the left and the right side of the router. The images also show some protruding cable and that is a re-visit of the serial cable modification.

Note that the built-in antennas are well-attached and after removing them, there is some excess material on the side that was meant to give the old antennas a better grip. This excess material can be removed with a cutter in order to provide better grip for a washer that will fix the RP-SMA socket into the plastic. Without cutting out the material, the washer would just end up compressing onto the excess plastic unevenly.

For estimates, the cable length should be about (or ) but no more or the excess cable will end up tucked allover the place when the small case closes. In fact, even should be enough but it is still better to have some extra clearance just in case the cable ends up wrapped differently or other mods are performed.

Here is the final result, with the two sockets fitted on ether side of the router and just ready to accept two external antennas on either side.

For ideas, note that there exist "sectorial antennas", that is, very large outdoor antennas meant for large open areas, that are not too expensive and can work indoors as well. The range of such antennas is huge by comparison to the mean-average house and even a router this small is able to perfectly provide wireless to clients on such a wide area. More or less, such is the power of the 70/30 rule.