LAOS Laser

Yeah, if pin p20 is no longer used there is no reason to have it connected. What's your goal with the smt board? Do you also want to replace the mBed with a separate lpc1769 and lan phy?

In my hackerspace, we've just bought a new laser cutter, and plan on having a full access control & laser-time charging built in.

The initial plan is to make a simple LCD board we can plug our arduino-based access control system straight into, replacing the i2c LCD with a bigger screen with some optocouplers to allow it to enable / disable the laser, and detect laser tube time. While I could implement this with a full LAOS board, I would want 2 or 3 PCBs for playing around with, and they are expensive to manufacture due to the size, hence my mini-board.

I'm using a socketed MBED because I'd like to look at one day changing it out for the pin-compatible lpcexpresso and trying out smoothieware.

In the long run (this may be controversial!), I think it would be good to look at merging LAOS firmware into the smoothieware project. It has some nice things we don't (up to date grbl, modular architecture, multiple boards available, an active development community). Hardware-wise, due to the amount of optocoupling, LAOS is very well positioned to be a laser-specific board for smoothie operation, opposed to the current crop of 3d-printer aimed boards. Software-wise, as it stands the main features we have in the LAOS camp over smoothie are our laser-engraving functionality and visicut support, both of which will most likely be solved soon. Existing LAOS boards could be upgraded to smoothie using an lpcxpresso in place of the MBED (as they are pin compatible afaik).

Just my thoughts anyway :)

Does Smoothieware have ethernet support? Otherwise that's also a very big plus for LAOS.

Yep