1	2009 East Coast Large Scale Train Show
2	Unique Electronic Devices You Can Make!
3	Unique Electronic Devices You Can Make!
4	My Focus Using my electronics skills to enhance what can be done with a model railroad Building unique & custom circuits for model railroads Making presentations & writing articles about how to “roll your own” circuits to satisfy my need to teach!
5	Objectives Show how microcontrollers are programmed and connected to interact with railroad equipment (Hopefully) Excite you with the possibilities and enable you to begin experimenting!
6	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”
7	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
8	First Project: Flashing Crossing Lights Design objectives: Alternately flash two red LEDs Operate from battery power Alter timing and other characteristics from software
9	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
10	Flashing Crossing Lights Parts: Cost: Less than $10.00
11	Flashing Crossing Lights Software: free from www.picaxe.com
12	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 4.5 to 5.5 volt power supply (3 @ AA cells) Can operate with as little as 2 volts Higher voltage needed for programming
13	Flashing Crossing Lights
14	Flashing Crossing Lights
15	Flashing Crossing Lights
16	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.
17	Flashing Crossing Lights Program 2: modified to flash for 10 seconds and turn off for 10 seconds
18	Flashing Crossing Lights Program simulation is built in!
19	Flashing Crossing Lights Hardware modification for button or reed switch activation:
20	Flashing Crossing Lights Program 3: modified to flash 5 seconds on each button push
21	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.
22	Two Sensors for Crossing Program 4:
23	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
24	Lighthouse Beacon
25	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
26	Lighthouse Beacon – 4 LEDs
27	Lighthouse Beacon – Halogen Bulb
28	Lighthouse Beacon Pulsed Width Modulation
29	Lighthouse Beacon Program #6
30	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
31	Flashing Crossing Lights on Steroids! Program 5:
32	We Can Now Control Lights Motors Turnouts Relays Most electrically powered devices
33	Going Farther . . . The two sensor crossing light control can easily be modified to make a “safe crossing” that can be used by two trains
34	Going Farther . . . When the first sensor is reached the power is removed from the secondary line
35	Going Farther . . . Once the main line train has passed the second sensor the power is restored
36	Going Farther . . . We substitute a relay for the LEDs. It controls the power to the secondary line
37	Going Farther . . . 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
38	Going Farther . . . More sophisticated optical sensors only release the stopped train after sensing that the last car of the main line train has passed
39	Your Ideas? Questions?
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