1	2008 Garden Railway Convention
2	Unique Electronic Devices You Can Make!
3	Introduction – About me: Retired from public education An active model railroader for 6 years Electronics, ham radio, woodworking, computers & programming have been hobbies for decades Model railroading is a nice way to utilize those other interests
4	Introduction – About me: Primarily interested in: using my electronics skills to enhance what can be done with a model railroad Building custom circuits for model railroads Making presentations & writing articles about how to “roll your own” circuits to satisfy my teaching instinct!
5	Objectives Provide an overview of “hobbyist” microcontrollers Show how microcontrollers are programmed and connected to interact with railroad equipment Demonstrate various devices & projects that utilize microcontroller operation (Hopefully) Excite you with the possibilities and enable you to begin experimenting!
6	Hypothesis 1 We all have an interest in how things work and many of us have enough knowledge of basic electronics to know that something can be done… we just need a bit of help putting all of the parts together to make it happen!
7	Hypothesis 2 We Already Know About & Have Experience With: Batteries & power supplies Track wiring & motors AC, DC, voltage, amperage & resistance LEDs & incandescent bulbs Series & parallel circuits Switches, relays & transistors Programming
8	Hypothesis 3 Inexpensive microcontrollers allow us to optimize the basic electronics and programming knowledge that we have so that we can do some amazing (and personally satisfying) things!
9	“Hobbyist” Microcontrollers They have been around for almost 20 years Usually dedicated to a single purpose Small Inexpensive (lately!) Programmed in BASIC No special programmer needed Found in many railroading devices (DCC, sound, radio control)
10	Highly Recommended: PICAXE Designed in the UK for use in schools SUPERB support Free manuals, tutorials and software Active & helpful forums on their web page & elsewhere on the web PICAXE manuals, especially “section 3- Interfacing Circuits” are super in helping to put it all together on your railroad Book: “Programming & Customizing the PICAXE Microcontroller”
11	PICAXE Best choice in terms of: Capability Ease of use Cost Support dave@davebodnar.com Many PICAXE articles at Large Scale Online & www.trainelectronics.com
12	PICAXE Underlying chip (PIC) is from MicroChip … about 2 miles up the road right here in Chandler! How is that for a local connection to a British product?
13	First Project: Flashing Crossing Lights Design objectives: Alternately flash two red LEDs Operate from battery power Alter timing and other characteristics from software
14	First Project: Flashing Crossing Lights Then we will modify the circuit to: Start from a button push Do other “flashing” things by making minor changes in hardware & software
15	Flashing Crossing Lights Parts: Cost: Less than $10.00
16	Flashing Crossing Lights Software: free from www.picaxe.com
17	Flashing Crossing Lights Other items needed: Any Windows PC with serial port (or USB to serial adapter) Programming cable Needs only 3 wires - can use an old mouse cable http://www.allelectronics.com/cgi-bin/item/CON-243/search/3-PIN_CONNECTOR_W_HEADER,_.1%22#34;_.html http://www.allelectronics.com/cgi-bin/item/DB-9S/search/D-SUB_CONNECTOR,_9_PIN_FEMALE_.html Soldering iron & wire cutters, etc. A Solderless Development Package is available from www.phanderson.com for < $20.00 4 to 5.5 volt power supply (3 @ AA cells)
18	Flashing Crossing Lights
19	Flashing Crossing Lights
20	Flashing Crossing Lights
21	Flashing Crossing Lights Program 1: Notes: “start” is just a label telling the “goto” where to go the program remains in the chip’s memory until it is manually erased or overwritten.
22	Flashing Crossing Lights Program 2: modified to flash for 10 seconds and turn off for 10 seconds
23	Flashing Crossing Lights Hardware modification for button or reed switch activation:
24	Flashing Crossing Lights Program 3: modified to flash 5 seconds on each button push
25	Two Sensors for Crossing Add a second sensor so that the light goes on when it passes one sensor… …and goes off when it hits the other sensor.
26	Two Sensors for Crossing Program 4:
27	Digression #1 The two sensor crossing light control can easily be modified to make a “safe crossing” that can be used by two trains
28	Digression #1 When the first sensor is reached the power is removed from the secondary line
29	Digression #1 Once the main line train has passed the second sensor the power is restored
30	Digression #1 We substitute a relay for the LEDs. It controls the power to the secondary line
31	Digression #1 Clever placement of diodes allows one relay to control the train movement based on direction of travel The train never stops after it has already passed the crossing, only before the crossing
32	Digression #1 More sophisticated optical sensors only release the stopped train after sensing that the last car of the main line train has passed End Digression #1
33	Lighthouse or Airport Beacon Design objectives Gradually brighten a bulb or LED to near full brightness Momentarily flash to full brightness Gradually dim till off Delay for a set time Repeat Able to use LEDs or incandescent bulbs
34	Lighthouse Beacon
35	Lighthouse Beacon Parts Adds one resistor and one transistor to the original flasher circuit so that the PICAXE can control a high current bulb The most significant changes are to the software
36	Lighthouse Beacon – 4 LEDs
37	Lighthouse Beacon – Halogen Bulb
38	Lighthouse Beacon Pulsed Width Modulation
39	Lighthouse Beacon Program #6
40	Lighthouse Beacon The transistor makes it possible to drive a very bright bulb Substitute a motor for the bulb and you can control a train’s DC motor! The size of motor is only limited by the size of the transistor
41	Flashing Crossing Lights on Steroids! Program 5:
42	We Can Now Control Lights Motors Turnouts Relays Most electrically powered devices
43	Digression #2 LEDs have certainly come a long way in the last 10 years They are bright enough to be used as headlights on our model locomotives
44	Digression #2 Groups of LEDs can be configured to do some remarkable things …like creating a realistic Mars light
45	Digression #2 … or ditch lights
46	Digression #2 Or even a headlight that is too bright to view directly That can turn into a single bulb Mars light End Digression #2
47	Actions Start Based on Time Switches of all kinds Toggle switch Push button switch Reed switch & magnet Any type of sensor Motion, sound, temperature, light, etc Note: several articles on sensors at LSOL & www.trainelectronics.com
48	Animation
49	Animation
50	Animation
51	Animation
52	Animation
53	Animation
54	Animation
55	Animation
56	Animation
57	Animation
58	Animation
59	Animation
60	Animation
61	Animation
62	Animation
63	Animation
64	MP3 Sound System
65	MP3 Sound System
66	MP3 Sound System
67	MP3 Sound System
68	Animation – Radio Control
69	Animation – Radio Control
70	Other “Gizmos” & Custom Circuits
71	Multi-Scale Train Speedometer Final design: 4 line x 20 character backlit LCD display Supports scales from 1:1 to 1:220 Common scales identified by name Track-side sensors Counts laps Gives speed in real & scale MPH Option to “beep” out speed English or Metric units
72	Multi-Scale Train Speedometer Wireless option: Uses radio transmitter on a modified car Senses train speed and sends it to the display unit Also can report voltage and current on a battery operated engine
73	Multi-Scale Train Speedometer Voltage and Current can also be included in the packet that is transmitted
74	Auto-Reverse Controller Originally designed to operate the motor on my holiday incline Repurposed the Speedometer by adding a power transistor, relay and additional control buttons
75	Auto-Reverse Controller BARC 2 Potentiometers to adjust time / speed 2 Buttons to set options Mosfet to handle high (10 amp+) current motors 3 LEDs to show time & laps completed 176, 172, 167, 163, 158, 154
76	Custom Designs Dual tower lift bridge geared stepper motors TV remote control programming
77	Custom Designs Crossover collision avoidance control Main line & trolley point-to-point cross Sensors operate trolley and stop or start it based on the position of the train
78	Custom Designs Complete 3 train switching controller
79	Your Ideas? Questions?
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