Look for what's not there ... the connection to the black wire. The true ground is provided by the USB cable.undertoe:
The drawing you attached, looks the same as mine. did you do anything different? So for the voltage regulator would i just input to the + battery, ground just hook up the ground on the aurdiuno and then output hook to vin on the aurdiuno.
Why shouldn't it ? It has all the needed "parts". The reason it didn't work before was that the black wire wasn't/isn't the ground reference for the circuitry.undertoe:
Why does it work in that way.
undertoe:
Also anything i can do to decrease the wasted voltage since i am taking it from 16.2v to 5v with the regulator.
Hmmm, you might measure the voltage from the USB ground to all the battery leads and see if there’s one that’s lower than 16v. Other than that I might advise putting a power resistor in between the battery and regulator so a to reduce the power dissipated by the regulator.
You may need to do that on the D- line as well, I don't know how the Neato judges connected or not. Perhaps it's the lack of 5v from the USB ? That would be easy.undertoe:
Also to simulate a usb disconnect (because the neato requires usb to be disconnected to preform any move commands) I have a NPN transistor that i have the base wired to a resistor and the output of a digital pin. then C & E break the + going to the usb port. So then i just flip it to output high when i want to send a command and then low when i am done issuing the command. Do you see any problem with that?
As for the NPN … I think a FET would be a better choice and they make ICs for just this purpose (multiple FET switches in a single package). Even a small 3pole relay would work. In any case make sure you keep the ground connection that the USB cable provides.
Yea just wondering since i am new to electronics stuff thanks for explaining it, it makes sense a little bit better.