Just a quick finding:

DDX with only DCC is not managing to send the idle packet….

DDX with MM activated does  😯

I have made the test with the option of MMLP (long pause for motorola)… and still, the idle packet is sent.., but the normal packets (in the experiment for loco 23) is never sent.

I have been trying to find out why the ttyAMA0 port is not working with rocrail.
So far, I have not found the answer… but it is clear that the port generates with no problem the Motorola packets, but not the dcc ones.
I have been capturing the output with the oscilloscope and decoding them, with only dcc active… and including one loco and no loco.
The outcome should be the idle packet as sent by rocrail:
11111111111111101111111100000000001111111110
When I used an USB converter, that is precisely what is obtained…now, when I used the AMA0 port… it seems not being able to generate even the right bit code:
In the picture: 11X…

After two 1 received… there is a weird signal… neither a ‘1’ nor a ‘0’
I have also tried to measure directly from the GPIO pins… and the results are the same – discarding any problem with the board I prepare to adapt the voltage levels.

So next step… see if the problem is in the way rocrail manages the serial port… or if it is just a problem with the AMA0 port – for that I would need some help form the rocrial community.
PS:I have made test to send a file of 2MB at the baudrate used to generate dcc packets… and it arrived with no problems to my PC.