This is the outcome from a previous thread, but as I have made progress I thought it merited a more apt title.
I have managed to attach a HLK-RM04 module to the Aux-1 port on my RAMPs board and by using a Virtual Serial Port on my PC. This means that software that controls the Arduino normally via it's USB-Serial can with no modification now control the RepRap over a wireless network or by ethernet. With Port Forwarding you can even control it over the internet (Heavy Heavy Caution! advised)
Image may be NSFW.
Clik here to view.
I have written up a short guide that should give you an idea on what is involved. I will adjust or add to it based on feedback.
Click here to view guide!
And here is the kicker... The HLK-RM04 Modules start at around $11 in price. Even the Development Kit is around $27 including delivery!
I have managed to attach a HLK-RM04 module to the Aux-1 port on my RAMPs board and by using a Virtual Serial Port on my PC. This means that software that controls the Arduino normally via it's USB-Serial can with no modification now control the RepRap over a wireless network or by ethernet. With Port Forwarding you can even control it over the internet (Heavy Heavy Caution! advised)
Image may be NSFW.
Clik here to view.

I have written up a short guide that should give you an idea on what is involved. I will adjust or add to it based on feedback.
Click here to view guide!
And here is the kicker... The HLK-RM04 Modules start at around $11 in price. Even the Development Kit is around $27 including delivery!