Guru
Joined: 31/12/2016
Location: AustraliaPosts: 1051
| Posted: 12:18pm 21 Nov 2021 |
The RC smoke oil used for these is usually oil based, some have tried making there own with some success, but some smoke units fail easily when the wrong stuff is used, that can be costly to replace a smoker is some of these locos.
Likely going to do my own from now on, just a wire wound resistor of the correct resistance to suit.
The 10sec recorder player would be ideal for some track side equipment, will get some of those.
One I have done already and happy with it, used an arduino Nano to run a DFPlayer Mini with 8gb SD card, play first track once then second track is played in a loop, I managed to get no gaps or blips in sound playback.
Dad had a diecast model of a V16 Caterpillar Genset, it would be some track side equipment outside a factory or something like that'
Found a YT video of a V16 Caterpillar Genset being load tested, start up and run, perfect, the start up track was maybe 15 seconds, the next track was about 2 minutes as as you could hear the turbo's spin up after the first and second load bank was switched on, by the time the 3rd and 4th load bank was switched on the turbo was really screaming, was sounding good, with a long loop it sounded like it was in use and I could not tell it was a loop.
With the loco engine sound, we like to have it as realistic as possible, real sound recordings are used, usually start run and shutdown.
This is (as fare as I am aware) converted to digital ( or polyphonic) sound, the engine run sound is where things get a bit more tricky, the engine revs need to increase as the PWM (or DCC) throttle is increased, or notch up change gears or whatever configuration that is necessary, some even have engine load as well.
I'm guessing this is done by some cleaver programming, also other sounds must be able to play simultaneously with no interruptions to other sound, not all can do this. Piece of cake on a computer.....
The LGB - Retrofit Sound Decoder (G Scale) has a great many functions and feachers, but like most of these things I can't for the life of me, see why they would cost so much, boards don't cost much to make in bulk lots, not a lot of expensive components used, the firmware, once its done is just uploaded as is the choice of sound and they have already done all the work.
There was an example done on an arduino nano (or one of them) but I think it was somewhat limited, some time back I saw a very interesting light and sound card build using an ESP32 https://github.com/TheDIYGuy999/Rc_Engine_Sound_ESP32 with instructions on how to edit a sound file so it could work with the card.
Now I'm guessing the engine sound is used in conjunction or converted in to some sort of LOOKUP Table (I could be Wrong) haven't studied it too closely yet.
There is quite a list of sounds already made to run, just have to activate the correct one and corresponding parts before uploading to the ESP32.
I'm getting some PCB's made along with the remote control that it works with, as a friend will be using it for another project, I will get the opportunity to try it, sound output will be through the pam8403 amp.
I would like to try getting the engine sound from the GM 671 in the shed, But will have to muffle it down a little, its straight out the manifold and ear muffs are a necessary just to be anywhere near it.
Also had the 3 cylinder Perkins running a welder it had a nice idle sound when we used large piece of water pipe over the end of the muffler to divert the exhaust elsewhere when we was welding.
Some cameras and mobile phones tend to automatically adjust and stuff up the sound recording at times.
The arduino's I think are somewhat limited in memory for doing too many things at once, and the Nano I have noticed the price hike lately.
There was some YT vids of it in action, I liked Union Pacific 2002 SD70M locomotive horn, should have one on the tractor.
Perhaps the Pi Pico RP2040 or something similar might be up to the task, At the moment I don't have a clue about how these work and the programming is beyond me as well, might pickup a few ideas overtime.