This is also confusing as it states it should be a 38bit int but says it holds +/-13,743,895.3471meters.
(2^38) / 13743895.3471 = 2000. So the divisor is 2000
This thread started going off-track very early.
/ 13,743,895.3471 is 20 000, not 2000.
A simpler way of looking at the problem is to examine the value 237
(don't forget the sign bit) = 137 438 953 472.
Look familiar? Now divide it by 10 000, giving the 1/10 mm resolution already mentioned.
I can't believe that converting a 64 bit IEE754 number to this representation is all that difficult using "long long" arithmetic.
It won't be fast, but things that use numbers with this sort of range rarely (in my experience) require speedy calculations.
However, if there is a similarly-priced platform that will handle 64 bit IEE754 natively, that's the solution I'd go for.
Sure it can be done. It is just a matter of getting all of the details correct.
Lets see, Adafruit has just started selling the Teeny 3.0 chips for $28 (US): http://www.adafruit.com/products/1044
. The teeny provides an IDE based on the Arduino IDE, so it should be similar to what you are used to. Note, it does not do FP in hardware, but does it via software emulation.
Raspberry Pi is around $40, and it does support hardware FP, but it runs Linux instead of the standalone environment used on Arduinos. You can get pi-plates (i.e. shields) to get access to the GPIO pins, but it is not a hard realtime system. http://www.adafruit.com/products/998
As I mentioned DUE is supposed to be formally announced on October 22nd. It does not have hardware FP. The rumored price is $49.
Itead Simplecortex, $45, software FP: http://imall.iteadstudio.com/featured-product/im120410002.html
Iteadmaple, $22, software FP: http://imall.iteadstudio.com/special-product/im120411012.html