Villy’s Electronics for Model
Railroads
Site
Pictures served
up from my VAX – which isn’t always up:
Astronomy, Simh and Aircraft Photos can be found here.
Pictures from the
Alberta Railway museum can be found here Train
pictures
Pictures from Coalspur and Parkhill Junction in
the Alberta Coal Branch
A Franklin Railway Supply Co
add from 1932 featuring a TH&B 2-8-4 a colour jpg
or b&w tif, the other side.
A colour tif served up by my virtual vax –
which is not always up.
Lighthouse
(updated 25 Jun 2007) : The kids
bought me a lighthouse for the garden last year – nice but the light was
constantly on. When the water wrecked the electronics, I built a flashing
(with fade in and out) unit with power saving features around an ATMEL
microcontroller. Also a version without the battery
save stuff, making it more suitable for a train layout…
$$$ and More $$$. If you see
costs quoted anywhere, it is my estimate of what it will cost you to acquire the
parts required from a reasonably priced supplier. I do all my mail order
buying from DigiKey and my local purchasing from Active Components (I live near
a major Canadian city).
Coded Infrared car detector
This page
contains all of the information that you will need to build the Car Sensor. The software has been updated to reduce
the probability of a spike at power up putting it into calibrate mode by
mistake
Auto Reverse Controller (aka
Shuttle Controller)
This page contains some of the information for the Shuttle Controller (auto reverse
controller). This project is pretty well ready for prime time.
Lighthouse (updated 25 Jun
2007)
Two
versions – a power miser one for battery operation and one this uses a
little more power…
Diagram
(jpg) for using leds to light up my passenger cars – correction to
diagram. Also note – ground symbols do not indicate a connection to the
car chassis. They only indicate the common ground for the lighting system
in the car.
Diagram
(jpg) and software for
the single led firebox flicker…- note this software
currently drives all of PB0 through PB4. Each pin is driven by a LSF
(Linear Feedback Shift Register) with a different maximal length – anywhere
from 4 million to 4 billion bits in length. The assembler version only drives a single port (PB4) with a 4 billion
bit sequence/
Ongoing Project – Semaphore
Controller
Slow motion
controllers for turnouts, semaphores etc, with
electronically settable end points that you can build for less than $20. I am
building this to work with the car detector, a still to be build block
occupied controller, rc servos (which are available
for less than $10) and a semaphore built from an article by Jim Atkinson http://www.bytedesign.com/mer/MEReLocal_Files/2002/LOCAL%20JAN-FEB%2002.pdf
I started this project with a ATtiny45 and after many hours of fiddling trying to get a
nice slow and smooth motion on the rc servo, realized
that I didn’t have enough IO pins (only 5 usable) on that microcontroller to do
everything that I wanted. Part of the problem was that I didn’t want to use
filters for the searchlight. I wanted to use a 2 wire red/green led
(which makes a reasonable orange if the polarity is switched fast
enough). The in-the-field calibration would need at least a couple more
pins so..
- 2 pins for the search light
- 1 pin for the servo
- 2 pins for the block occupied
signals
- 2 pins (or maybe more) for the
in-field calibration….
I am currently re-writing the
code to work with the ATMega88 chip. This is tremendous overkill (it has
23 usable IO pins), but it was in the parts box. Once I get it working
the way that I want it to and the budget allows, I will migrate it to something
a little more reasonable – like an ATtiny24 (14 pins – 11 usable).
Future Projects
Block occupied
controller. Since the car detector can only tell if a car is passing
over, something additional is going to be needed to make a block occupancy detector.
The method that detects current drain in a block has a certain appeal (and is
the only way that I can think of that should always work) – but the thought of
adding resistors to the wheel sets of all of the cars doesn’t. I haven’t
decided how I am going to do it yet, but a thought is to use a modified car
detector with two IR Receivers – that will allow me to determine
direction. One of these at each end of the block and a controller to keep
track would work – most of the time. It won’t detect a dropped car for
instance and it won’t always identify blocks that are occupied at power up.
Controller for
search light type block control signals (driven by the Car Detector – or any
other sort of detector that can provide an active low signal)
A very complicated
(from a functional perspective) DC throttle with the following features:
Stored
configuration data for multiple locomotives (8 sounds like a good number)
Settable min/max
throttle & pulse settings for each locomotive (so they all start at the
same throttle setting and reach their maximum scale speed at the same throttle
setting
Train size setting
(variable momentum control)
Air brake
functionality – waste you air & you have a runaway – (with an EMERGENCY as
distinct from an Emergency brake)
Bar code read out
for power setting, speed, air pressure etc.
If you have any questions or
ideas, drop me a note at
2007-03-04
