Wonky DCC++ and digitrax module question

[KiloWhiskey]

I have an uno and motorshield (real Arduino) with the jumpers in pos 5 to 13, 10 to 12, and 12dc walwart to the shield power in from a wallwart. Followed the troubleshooting threads, and made the com port speed setting adjustments,  as well as the options settings in decoder pro. When i scan for decoder on DP, it says scanning cv8 then gives error saying "stopping due to error: no acknowledgement.

Now, I currently only have one decoder, a (way)used digitrax DN 140. Its used, so i started with just a Led connected to the white and blue lines, then to the program track. When I run the read cv for manufacturers scan, the led does flash a few times.

I did swap the uno for a clone, and have same results. 
My Java is up to date, the track power on DP is on and I show 4 leds lit. On the main board i show a solid yellow and and green power.
So my question (s) are should I buy a new decoder and try again? Or is this an uno thing?

Thanks.
Ps, yes I will eventually get Rail Pro.

[G8B4Life]

I don't have any experience with Arduino so  I can't help with any of that part but one thing on the decoder side from memory is that a load on the motor outputs sometimes needs to be present for the decoder to work properly. I can't remember where I came across that information but it could be worth a try. You don't even need to use an actual motor, you could use a resistor instead.

- Tim

[KiloWhiskey]

Makes sense... I will give it a try. Ty

[KiloWhiskey]

Tim for the win... I clipped the arduino kit toy motor to the orange and grey leads..... read perfect. Thank you again

GO ARMY BEAT NAVY

[KiloWhiskey]

I can read all cv's now, but it will not write changes now...