HM7000 sound but won't move on dcc

[Dazzlerofker]

Hiya

Got an 8 pin one of these in a bachmann class 37. If the chip is in Bluetooth mode it's all good, sounds light and movement all fine but if I put it into DCC mode I can use the lights and the sound but the loco won't move

I'm using JMRI with a DCC-EX command station (Arduino based)

Anyone had this issue? Have tried a reset on the decoder but does not seem to make a difference.

[SteveM6]

I suspect that the loco address has not written across from the app to the decoder (known issue under investigation).

Try programming the decoder with the address from a DCC controller.

[Britannia Builder]

If the sound and lights work under DCC, then presumably the DCC address is OK.

The only two cases that I've had of these symptoms have been a motor overload which cuts the motor power but not the sound (but this would affect Bluetooth as well) and inadvertently setting F27 Brake on, which prevents the loco moving. I'm not familiar with JMRI - could F27 be set without you noticing it?

Regards, John

[Dazzlerofker]

No the brake is not on, I say it's a bit odd as it works perfectly on Bluetooth but on DCC when increasing the speed the engine revs up but the loco does not move.

I assume the address is ok as it is responding to functions just not moving.

Tis a bit odd.

[Britannia Builder]

It might just be worth trying to run auto-calibration, which applies maximum voltage to the motor and bypasses back EMF control, and see if this makes the motor run. You'll need to be under DCC control, but you can use Bluetooth to set CV149 to 0, then set F0 on the DCC controller to start the auto-calibration.

Regards, John