"@Charles,  I could but I won't.  The PX4 original is in eagle.  Re-using the existing open source design and contributing back to it is easily worth $150.
I tried kicad.  The libraries are simply awful.  Overall it comes across as the  brainchild of…"

"@Charles,  I did do the board design myself. It's the only way to get what I want and to properly review the layout.  That's an extra $150 for the private eagle license.  If I ever want to sell these things then that will be an extra $500.
As I said…"

"@Ye, MAX21105 is more accurate than MAX21100 and cheaper. Availability was just a little too late for this project. It is cheaper since it does not have the motion merging engine that we can't use anyway. The interrupt mechanisms are simpler and I…"

"@Roberto, I forgot to say that the debug connector is too deep to be mounted when fitted in the aircraft.  Anything but through hole connections is a no go. "

"@Bill,  Not much market at all so far. I did this to make sure that I have something that fit inside the aircraft.
I don't plan to sell them since I will get into arguments with the local tax man and he will take most of my money away.  I might get…"

"@Roberto,  Not much difference apart from size.  If it doesn't fit inside the aircraft it is as much use as all the other options.

AUAV-X2 comes in at 30*45mm which is smaller than the uNode. That will fit nicely in the autopilot space I have.…"

"@Mark MAX21100 is one of the lower cost sensors.  Around $3.50 @ 1k volume.  It doesn't make any sense not to put it on.  It will make a nice backup autopilot with an extra gps somewhere on the bus system.
The 64Mbit memory is about $1.  I would put…"

"@James Pike - That is pretty much my thinking also.  Thanks for the feedback.

@ben @thomas  The FFC or sensor damping idea is nice but simply not for this project.  Any additional connectors add too much size.  I am already concerned that the power…"

"@James Pike.  Out of curiosity what would you use it for?

@Kees.  I have not decided on the configuration yet bu it is at least three.  Two for the wings and one as a failproof.  Then the autopilot of choice plugs into that system.  If all the…"

"@Mark,  debug is working after I discovered the bootloader update.  I used it to get the qgc mavlink-ftp file upload working.
It looks like I am using rev Y silicon.  How fu**ed am I?

I could do with getting some good luck on this project for a…"

"@benbojangles, I am not a company so this was funded with my pocket money.  Anything other than very simple is too high risk and too likely to need respins.  The prototype cost already runs at $1500.  MAX21100 cost is low and flexi proto pcb cost is…"