More adventures with DCC Options

[Doug]

As promised, here are a few photos of the DCC adventure. I had played with this idea for a while and I had the kit lying about. I don't have any lane-changing gear and I don't plan on building any. I'll wait for Scalextric to bring one in to try that aspect of the system. Using a train controller for cars is not that cool. A rotary knob for acceleration is not naturally logical and the cars come off at high speed due to inability to slow down fast enough at the bends. The fault is the driver turning the knob, not the deceleration rate programmed into the chip. You can program the acceleration and deceleration, but that is almost useless. It is designed for trains that take a long time to get going, not for cars.

Here are the chips that I use. Top and bottom:


A close-up:


It fits very nicely behind the driver in the Scalextric C3 Corvette. When the body is on, you can't see it at all:


This is how you program the chip. I have an extra piece of track attached to the programming circuit of the DCC controller. You pop the car on, call up the CV addresses and write them to the chip in the car:


Here are the two Corvettes with chips in on the same lane. This is just an exercise in functionality and at the end of the day, they just go around the track on the same lane. It is fun to see them catch up with one another and it is fun to turn the lights on and off independently - only because it couldn't be done before:


Here is an animated GIF of the Lighting function. I don't have a digital video system unfortunately, so you'll have to accept this. The chip has 2 light circuits and and extra one for horn or whatever. This extra function could actuate the lane change on a Scalextric track. You would just need to rig it up to a LED under the car to switch the lane. Light are switched on and off via Function 0:


To get this working properly, you need a controller that can replace the train one. That is the most important thing. You'll need the function buttons on the controller too to actuate the lane change etc. This - I assume is what Scalextric have done, so I'm waiting for that before inventing anything.

[astro]

nice bit of research! thanks for posting your findings

[lordjw]

Hi!

Nice pics Nuro. Thanks! I have come to same conclusion, I will wait for Scalextric system and if it is affordable and works reasonably well, I will use it.

DCC decoder at the pictures seems to be the very basic decoder with Microchip PIC controller, ceramic resonator, power fets, external eeprom, couple of OpAmps and diodes. Easy to build, cost of components relatively low. Disadvantage of your decoder is that the program cannot be upgraded since PIC16C715 is OTP (one time programmable) device.

If Scalextric system is disappointment I'm prepared to develope improved CarDCC. If anyone has some blueprints for communication protocol and bi-directional DCC device, please step forward.

I think this could be a golden opportunity for DAVIC inventor. If we could have the same protocol that D. uses, we could establish standard using proven system. I'm not asking complete how to build instructions, just blueprint that describes electrical and communication specs. I am sure it wouldn't hurt DAVIC business, there are always people who will buy ready made components.

Just a thought

Julius

[Doug]

As I've been playing with this - and I must insist that it's only just play, I'm no electrical guru - It is very tricky to control the cars at any speed similar to what was used to race normally. Even with Acceleration and deceleration set to no delay, the response of the car is not immediate. Light are immediate, so I assume that the acceleration and deceleration is a train thing and perhaps there is more programming somewhere. I'll look at the controller a bit more. I've had it for years, but never looked at the advanced programming.

[astro]

with trains, when the station master says 'go', the driver has to finish his tea before opening the steam valve and setting off, hence the delay.

[RC45]

And class disruptor returns...

For what it is worth - the Digitrax UT1 controllers I am using actully fall in hand really well, and offer really good feedback, and feel more natural to me than trigger style controllers... they actually leand a very R/C model feel to the car's speed control.





But that's not to say that other folks may not want to have traditional pistol grip trigger controllers..

[Doug]

Interesting. What is that bottom controller designed to run?

I'm looking at the bus (XBUS) connection of the Controller that I have and will see if I can hook up another - more handy - controller to it.

[Maltese]

GREAT Discussion!! RC45, that hand controller looks like something from StarWars...in a VERY COOL way!

This is VERY interesting.

-Maltese

[RC45]

Just to clarify - this is some fandagled Radio Control car controller..

[Slotrace.dk]

Looks more like a hairdryer!

[Difflock]

I think the cylindrical part is the steering wheel


Mark.

[moped rider]

With blue tooth technology you don't need to hardwire the hand controller to the digital command unit. It would mean that club racers could stand anywhere around the circuit and not necessarily at the start/finish line. It does always seem odd to me that clubs always have the car control positions next the easiest part of the circuit (ie the longest straight). At Phoenix for example I would much rather be positioned near the technical part of the circuit as that is the area where races are won or lost. It is absolutely pointless watching the car at close proximity hairing down the long straight as I learn nothing about how the car handles. But all clubs are the same!

I suspect that there is some algorithm in Nuro's DCC control unit that provides a braking effect that replicates the momentum of a train. I cannot think of any DCC control system that has an immediate power cut off aside from that for emergency purposes such as a derailment.

Now of course that momentum effect may well be built into the slot car digital control systems so that cars brake realistically and maybe Nuro is the first in the whole world to control slot cars with a control unit where anticipation is required to slow a car into a corner. So a world first for Nuro!

Whether this adds to the experiance is open to question of course but it gives club racers yet another excuse to have a massive control unit with a mega number of switches and buttons slung around their waistline.


Moped

[astro]

- i think drivers are placed at the easiest part of the circuit so that they don't get in the way of marshalls

- braking is most likely to be achieved by applying reverse power to the motor, as in the Fly professional (and other) controllers

[moped rider]

There is logic to Astro's observation but never the less the best position for a racer at a club is at the worst part of the circuit where human senses require to be at their most tactile.

In terms of braking what has the reverse power thing to do with DCC control? That appears to be a red herring as DCC control does does not permit this sudden reversal of power. Is this why the braking is so delayed on Nuro's circuit perhaps?


Moped

[astro]

all digital uses a digital servo-control to supply power to the motor - via i believe a power amplifier chip (those with more knowledge on the actual components. please correct my mistakes!)

I suspect it will be as easy to impliment active brakes (applying reverse polarity current) as it would to try to impliment the passive braking (letting the motors back emf apply the reverse current). The active method allows for a lot more programmability and racing conditions simulations, since the controlling software can then adjust the braking to simulate slippy/wet roads etc.