751/752 Bardotka – 8bit General Project

Project Information

General sound project suitable for custom modifications, especially for individual light settings.
The sound project is designed for MX series 8-bit sound decoders.
Recommended minimum decoder software version is 40.22.
The decoder has a default address of 3.
Reset can be performed by setting CV8 = 8.

Function Assignment

Function mapping and CV settings can be modified.

F0 Position white lights

Affected function output: FA0v, FA0r
Direction dependent
F1 Reserved for lights

Affected function output: FA1
F2 Reserved for lights

Affected function output: FA2
F3 Shunting mode
- speed range reduced to ½
- reduces acceleration / braking times to ¼ of CV3 and CV4
- triggers short horn at start
F4 Short horn
F5 Coasting

Idle running sound regardless of set speed
F6 Engine acceleration to max RPM

Independent of set speed, even when stationary
F7 Long horn
F8 Sound on/off

Engine on/off
F9 Unused
F10 Short whistle
F11 Long whistle
F12 Uncoupling screw
F13 Coupling screw
F14 Sanding
F15 Dispatcher whistle - new

Call to readiness
F16 Dispatcher whistle - old

Call to readiness, departure
F17 Compressor
F18 Sound set switching

Loaded / unloaded locomotive, when stationary
F19 Wheel squealing in curves
F20 Station announcement

R 653
F21 Station announcement

Gemeran Express
F22 Station announcement

REX 1724
F23 Station announcement

REX 17225
F24 Station announcement

Os 5016
F25 Station announcement

Os 5028
F26 Sound muting
F27 Volume decrease
F28 Volume increase

Setting Maximum Speed

We recommend setting the maximum speed using CV57, not CV5. Setting the maximum speed using CV5 may change the sound pitch ranges. Acceleration time CV3 and deceleration time CV4 are not affected when the maximum speed is set via CV57.

Shunting Mode

In the general project, position lights are turned off in shunting mode. In many models position lights are commonly tied to the headlights. If you require position lights to be turned on together with headlights in shunting mode, enable it by setting CV37 = 3.

The mode reduces acceleration and braking times to ¼ of the CV3 and CV4 settings. If this behaviour is not desired, disable it by setting CV124 = 16. Full deactivation of acceleration/braking times is possible by setting CV124 = 19.

If shunting mode is not required at all, disable it by setting CV124 = 0.

The default shunting mode value in the project is CV124 = 18.

In shunting mode a short horn sounds at each start. This is implemented by a script.

Three conditions must be met for the short horn to play:

The function must be enabled via F3.
The engine sound must be enabled via F8.
The model must start from zero speed.

Set CV837 = 8 to disable this behaviour; default is CV837 = 0.

F5 Coasting vs F6 Engine to Maximum RPM

If both functions are enabled, coasting (F5) takes precedence.

Cab Lighting

When cab lighting is turned on via F9, it will automatically switch off when the model moves and turn back on when the model stops/starts. For technical reasons¹⁾ this is handled by a script. To disable this automatic behaviour set CV837 = 8 (default CV837 = 0).

If you want cab lighting without automatic switching during motion, set CV43 = 96 and CV837 = 8. To revert set CV43 = 0 and CV837 = 0.

¹⁾ Standard decoder behaviour allows either smooth fade in/out of function outputs or disabling outputs during motion, but not both at the same time.

Compressor

The project implements two compressor activation modes handled by script:

Random compressor cycles conditional on engine sound enabled via F8. This is stopped when compressor is manually turned on via F17.
Manual compressor activation via F17, conditioned by F8 being on and zero speed.

Set CV837 = 1 to disable F17 compressor activation.

Set CV837 = 2 to disable random compressor cycles.

Set CV837 = 3 to disable both (default CV837 = 0).

Curve Squeal

Curve squeal is implemented by script and requires several conditions:

The function must be enabled via F19 and engine sound must be enabled via F8.
The sound will not trigger at very low speed: set speed must be more than 14 (range 0–126).
The sound will not trigger at high speed: set speed must be less than 100 (range 0–126).

Set CV837 = 4 to disable curve squeal (default CV837 = 0).

Custom Function Mapping

Custom function mapping is possible via CV400–CV428. The project does not use these mappings by default.

Decoder Reset

If you make configuration errors or get lost in settings, reset the decoder by programming CV8 = 8. This will restore the sound project defaults.

Basic CV Settings in Project

CV3 = 16
CV4 = 14
CV5 = 1
CV6 = 1
CV33 = 1
CV34 = 2
CV35 = 4
CV36 = 8
CV37 = 0
CV38 = 0
CV39 = 0
CV40 = 0
CV41 = 0
CV42 = 0
CV43 = 0
CV44 = 0
CV45 = 0
CV46 = 0
CV57 = 125
CV105 = 145
CV106 = 5
CV124 = 18
CV125 = 88
CV126 = 88
CV127 = 88
CV128 = 88
CV190 = 3
CV191 = 2
CV254 = 201
CV255 = 1
CV256 = 10
CV266 = 100
CV374 = 5
CV339 = 6
CV340 = 6
CV395 = 130
CV396 = 27
CV397 = 28
CV836 = 0
CV837 = 0

Sound Sample Numbers

F4 CV522 23 Short Horn

F7 CV531 22 Long Horn

F10 CV540 42 Short Whistle

F11 CV543 43 Long Whistle

F12 CV546 44 Screw Coupler Down

F13 CV549 45 Screw Coupler Up

F14 CV552 46 Sanding

F15 CV555 47 New Dispatcher Whistle

F16 CV558 48 Old Dispatcher Whistle

F20 CV673 49 Express 653 Announcement

F21 CV676 50 Express Gemeran Announcement

F22 CV679 51 REX1724 Announcement

F23 CV682 52 REX1725 Announcement

F24 CV685 53 Os5016 Announcement

F25 CV688 54 Os5028 Announcement

script 57 Compressor

script 58 Wheel Squealing in Curves

"Script" means that the corresponding sound is used in the script, outside of normal use within CV. The sound number is listed here for possible standalone use of the sound when the script is disabled.