11

PICAXE PIC1

2014 Amherst Railroad2014 Amherst RailroadHobby ShowHobby Show

Dave BodnarDave Bodnar

January 23, 2014January 23, 2014

Amherst, MAAmherst, MA

Electronics, Microcontrollers & Trains

Electronic Gizmos, Gadgets, Tips, Tricks & More!

This presentation isavailable on-line at:

www.trainelectronics.com or www.davebodnar.com

Revised 01-20-14

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PICAXE PIC2

ObjectivesObjectives• Demonstrate various devices & projects that

utilize microcontroller operation …

• … and lots of tips & tricks and other things that do not!

• (Hopefully) Excite you with the possibilities and

enable you to begin experimenting and enhancing your railroad!

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PICAXE PIC3

Topics to be CoveredTopics to be CoveredPart 1Part 1

• PICAXE overview – What is it? Why use it? How do we use it?

• Build & program a number of PICAXE projects

• Explore a sprinkling of Tips, Tricks, Tools and new & improved gizmos & gadgets

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PICAXE PIC4

Topics to be CoveredTopics to be CoveredPart 2Part 2

• Animations & other PICAXE based projects

• …More Tips, Tricks, Tools

• …More new & improved gizmos & gadgets

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PICAXE PIC5

Working Hypothesis 1Working Hypothesis 1

We all have an interest in how things work and We all have an interest in how things work and many of us have enough knowledge of basic many of us have enough knowledge of basic electronics to know that something can be electronics to know that something can be done…done…

we just need a bit of help putting all of the parts we just need a bit of help putting all of the parts together to make it happen!together to make it happen!

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Working Hypothesis 2Working Hypothesis 2We already know about & have experience with

many of these things:• Batteries & power supplies• Track wiring & motors• AC, DC, voltage, amperage & resistance• LEDs & incandescent bulbs • Series & parallel circuits• Switches, relays & transistors• Simple Programming

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Working Hypothesis 3Working Hypothesis 3

Inexpensive microcontrollers allow us to leverage the basic electronics and programming knowledge that we have so that we can do some amazing

(and personally satisfying)

things!

88

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PICAXEPICAXE

• What can it do?– Intelligently control &

automate many aspects of operating your railroad

– Operate lights, motors, animations and other electrically powered devices

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PICAXEPICAXE

• Best choice in terms of:– Capability– Ease of use– Size– Cost– Support

• dave@davebodnar.com• Many PICAXE articles www.trainelectronics.com • Several Books available on Amazon – Search for PICAXE

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PICAXE - What You NeedPICAXE - What You Need1. Windows computer with

serial port or …

USB to serial adapter or …

USB programming cable

2. Windows computer running free PICAXE software

3. Power source– 3 @ AA cells = 4.5 volts

– Note:AxePad software is available for Mac & Linux computers – fewer features than PC software

1111

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TipTip

USB to Serial Adapter

Spark Fun sells PICAXE cable – part # PGM-08312 for about $26.00

Or

Spark Fun’s USB to Serial – part # PGM-09260 for about $15.00

Details on use at www.trainelectronics.com

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TipTip

• Peter Anderson (PHAnderson.com) has PICAXE chips & accessories

• Amazon & eBay – search for PICAXE

• SparkFun.com

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First Project:First Project:Flashing Crossing LightsFlashing Crossing Lights

• Design objectives:• Alternately flash two red LEDs • Operate from battery power• Alter timing and other characteristics from

software

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First Project:First Project:Flashing Crossing LightsFlashing 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

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Tip - Testing LEDsTip - Testing LEDs

• Just about any LED can be tested with a 3 volt lithium battery 2032, 2025, etc

• Touch the anode (longer wire) to the “+” side of the battery

• Touch the cathode (wire by notch in LED)

to the “-” side

White LEDs are OK for long use at 3+ volts, Red, Green, Amber are not

A great use for old watch batteries!

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LED InformationLED Information

• LED Related Articles:– A Simple Constant Brightness LED – LEDs 101 - Introduction & Overview – LEDs 102 - Using them Onboard Trains – LEDs 103 - Turning them On and Off – LEDs 104 - A Better Constant Brightness

Circuit for LEDs

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Flashing Crossing LightsFlashing Crossing Lights

Parts:Cost:

Less than

$10.00

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Flashing Crossing LightsFlashing Crossing LightsSoftware: free from www.picaxe.com

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Flashing Crossing LightsFlashing Crossing Lights

Our wiring plan is in the form of a schematic - a drawings of what we need to build and how it is wired togetherRemember: Don’t use a 9 volt battery

or 4 fresh 1.5 volt AA cells!

5.5 volts maximum!

2020

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Not sure about…???Not sure about…???

• A resistor’s value…

• Or a battery’s voltage…

• Or if a wire is broken…

• There is a tool for that!

2121

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I was blind and now I see…I was blind and now I see…

• Volt / Ohm Meters are right up there with indoor plumbing.

• Less than $10.00

• Sometimes free

• Use two to give both volts & amps

•See Trainelectronics.com for details

2222

PICAXE PIC22

Tip – Tiny Volt MeterTip – Tiny Volt Meter• Powered from voltage

being measured – 4 to 30 volts

• Approx 1” x ½” x ½”• Search eBay for:

“Ultra Mini size LED Volt Meter”

• $5.99 (or less) + $0.00 shipping

2323

PICAXE PIC23

Tip – Step Down Voltage ConverterTip – Step Down Voltage Converter

• Suntekstore.com • < $8 shipped – some times on sale for less• http://www.suntekstore.com/goods-14007039-adjustable_step-down

_dc-dc_power_module_with_voltmeter_display.html

• Up to 2 amps without heat sink

• Includes digital meter!

• Adjust voltage withscrewdriver

2424

PICAXE PIC24

Tip – Step Down Voltage ConverterTip – Step Down Voltage Converter

• Can easily be modified to use a larger potentiometer

• Inexpensive speed control for a small layout

2525

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Flashing Crossing LightsFlashing Crossing Lights

Radio Shack board # 276-002 $15.00

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Flashing Crossing LightsFlashing Crossing Lights

2727

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Flashing Crossing LightsFlashing 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.

high 1 ‘turn on LED 1 - pin out1low 2 ‘turn off LED 2 - pin out2

start: pause 500 ‘wait ½ second toggle 1 ‘switch LED 1 on pin out1 toggle 2 ‘switch LED 2 on pin out2goto start: ‘do it again

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PICAXE PIC28

Flashing Crossing LightsFlashing Crossing LightsProgram 2: modified to flash for 10 seconds and turn

off for 10

seconds

start:high 1 ‘turn on LED 1low 2 ‘turn off LED 2

For b0=1 to 20 ‘repeat 20 times pause 500 ‘wait ½ second toggle 1 ‘switch LED 1 toggle 2 ‘switch LED 2next b0 ‘back to looplow 1 ‘turn LED 1 offlow 2 ‘turn LED 2 offpause 10000 ‘stay here 10 secondsgoto start: ‘do it again

2929

PICAXE PIC29

Flashing Crossing LightsFlashing Crossing Lights

• Program simulation is built in!• You can write and test programs without any

hardware…• Give it a try tonight!

3030

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Flashing Crossing LightsFlashing Crossing LightsHardware modification for button or reed switch

activation:

3131

PICAXE PIC31

Flashing Crossing LightsFlashing Crossing LightsProgram 3: modified to flash 5 seconds on each

button push start:low 1 ‘turn off LED 1low 2 ‘turn off LED 2if pin3 = 1 then start: ‘if switch off go to top

flash: high 1 ‘LED 1 on low 2 ‘LED 2 offfor b0= 1 to 10 ‘do this 10 times pause 500 ‘wait ½ second toggle 1:toggle 2 ‘switch lights next b0 ‘do next of 5 loopsgoto start: ‘start from very top

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PICAXE PIC32

Two Sensors for CrossingTwo 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.

Sensor 1 Sensor 2

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PICAXE PIC33

Flashing Crossing LightsFlashing Crossing LightsProgram 4: modified to flash when one switch is

hit and stop after a 2nd switch is hit

Either of the

two switches

can be hit

first & it will only

stop after the

other switch

is hit.

PauseBeforeStart:'prevents detecting slow button push

low 1 : low 2 ‘turn off both LEDs

pause 1000 'pause 1 second

CheckButtons:

b1=0:b2=0

if pin3 = 1 and pin4 = 1 then CheckButtons

if pin3=0 then

b1=1 : goto flash ‘ set b1 to show it was hit first

endif

b2=1 ‘set b2 to 1 to show it was hit first

Flash:

high 1 : low 2 ‘LED 1 on & LED 2 off

FlashAgain:

for w3= 1 to 250 'check for button before changing lights

if b2=1 and pin3=0 then PauseBeforeStart

if b1=1 and pin4=0 then PauseBeforeStart

next w3

toggle 1:toggle 2 ‘switch lights

goto FlashAgain: 'continue checking buttons

3434

PICAXE PIC34

Tip - Reed SwitchesTip - Reed Switches• Two small metal

plates touch when near a magnet closing acircuit

• Contained withina glass vial – VERY Fragile!

• Many sizes available

3535

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Tip – Magnets for Reed SwitchesTip – Magnets for Reed Switches• Deal Extreme 10mm x 1mm Magnets (part

#13516)

• Very strong – 100 for $12.80 delivered!

3636

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Tip – Magnets for Reed SwitchesTip – Magnets for Reed Switches• Harbor Freight magnets

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PICAXE PIC37

Tip – Magnets for Reed SwitchesTip – Magnets for Reed Switches• SunTekStore magnets

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Tip - Free MagnetsTip - Free Magnets

• Salvaged from old Hard Drives

• Virtually all computer hard drives have strong (rare earth) magnets in them

• Remove case & carefully remove platters and other parts that are in the way

• NOTE: some platters are GLASS & are very, very fragile and easily converted to SHARP pieces!

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Tip – Magnets as ClampsTip – Magnets as Clamps

• I recently had to glue a sign to the middle of a building…– Putting a rare earth magnet on the front and

another on the back made it a snap!

• Also great – with “1, 2, 3 block” behind magnets– as couplers– to hold bodies on cars

4040

PICAXE PIC40

Latching Reed SwitchesLatching Reed Switches

• Pass a magnet over one end – it is ON

• Pass a magnet over the other end – it is OFF

• Great for turning battery powered lights on/off with a magnet on a stick

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Tip - ConnectorsTip - Connectors

We are always looking for ways to connect electrical devices together– For low current

use:– Deal Extreme

item # 15234– $2.99 for 10

pair includingshipping!

4242

PICAXE PIC42

Tip – ConnectorsTip – Connectors

• Connectors:– High current for

track and batteryconnections:

• Deal Extreme item # 10788

• $6.37 for 10pair includingshipping!

4343

PICAXE PIC43

Tip – ConnectorsTip – Connectors

• 3 wire Servo Cables have lots of uses• Can be used as is for 3 conductors or back-to-

back for 6 conductors• This is the type of connector that I use for

programming the PCAXE• Ideal for tender / loco connections in larger

scales• Ebay - $3.43 for 10 long extensions

http://www.ebay.com/itm/10pcs-150mm-Servo-Extension-Lead-Wire-Cable-For-Futaba-JR-/151082981725?pt=Radio_Control_Parts_Accessories&hash=item232d3f595d

4444

PICAXE PIC44

Tip – ConnectorsTip – Connectors

• Multi pin cables with sockets

• Great for connecting cars to one another, tenders to locos, etc

• Available in 2 pin 8 pin

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PICAXE PIC45

Tip – ConnectorsTip – Connectors

• Search eBay for jst 1.25 to find the smallest connectors

4646

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Tip – Tiny MotorTip – Tiny Motor• Gear head motor a bit larger than a penny• Surprisingly high torque• http://www.suntekstore.com item # 14002627 • Less than $7.00

shipped• Ideal for many

animations• Phil’s Narrow Gauge, too

4747

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Useless Gizmo AnimationUseless Gizmo Animation

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PICAXE PIC48

Tip – Dubro CollarsTip – Dubro Collars

• Ideal for connecting to motor shafts & to join piano wire for servos

• http://shop.dubro.com/c/aircraft_collars

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PICAXE PIC49

Tip – Heat Shrink TubingTip – Heat Shrink Tubing• Excellent for insulating joints & making

repairs• Soldering wires first is recommended but

not mandatory• Available in many colors – great trick for

identifying wires• Available in many diameters, too• Fry’s has an excellent supply, BangGood,

too!

5050

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Garden Railways Garden Railways PICAXE ArticlePICAXE Article

April 2013 Issuepages 54-59

Contains a detailed introduction to the PICAXE and several projects

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PICAXE ArticlePICAXE Article

Shows how to build:• Single LED

Lighthouse• Single LED Mars

Light• Morse Code Beacon

All using the same circuit

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Custom Circuit BoardCustom Circuit Board

5353

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Lighthouse BeaconLighthouse Beacon

• One of my most popular projects

• More complex than just on & off!

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Lighthouse BeaconLighthouse Beacon

• Parts– Adds one resistor and one transistor to the

flasher circuit so that the PICAXE can control a high current bulb or more LEDs

– The most significant changes are to the software

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Lighthouse Beacon – 4 LEDsLighthouse Beacon – 4 LEDs

5656

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Lighthouse Beacon – Halogen BulbLighthouse Beacon – Halogen Bulb

5757

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How does a pin that is normally either ON or OFF provide variable voltage?

Lighthouse BeaconLighthouse Beacon

Pulsed

Width

Modulation

0 volts

1.25 volts

2.5 volts

3.75 volts

5 volts

Something about this should be bothering you!

?

5858

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PICAXE ArticlePICAXE Article

Single LED Lighthouse

#NO_DATA 'speeds up programming

#Picaxe 08M2 'identify the chip

SETFREQ m32 'speed it up to 32 MHz

SYMBOL Loopie = b2 'label variable b2 as Loopie

SYMBOL Brightness = b1 'label b1 as Brightness

SYMBOL Dlay = 150 'set constant Dlay to 150

Start:

For Loopie = 0 to 100 step 1 '100 steps from off to bright

brightness=255-loopie

pwmout c.2, brightness, loopie 'use PWM to brighten the LED

pause Dlay 'pause a bit

next loopie 'get the next item in for/next

pwmout c.2, 255,1023:pause 1000 'flash to full bright briefly

for loopie = 100 to 0 step -1 'repeat above backwards

brightness=255-loopie

pwmout c.2, brightness,loopie

pause Dlay

next loopie

pause 2000 'pause a bit with LED off

goto start 'do it again!

5959

PICAXE PIC59

PICAXE ArticlePICAXE Article

Single LED Mars light

#NO_DATA 'speeds up programming

#Picaxe 08M2 'identify the chip

SETFREQ m32 'speed it up to 32 MHz

SYMBOL Loopie = b2 'label variable b2 as Loopie

SYMBOL Brightness = b1 'label b1 as Brightness

SYMBOL Dlay = 2 'set constant Dlay to 2

Start:

Gosub ShortFlash 'do the shorter flash routine

Gosub LongFlash 'do the longer flash routine

GOTO Start: 'repeat

ShortFlash: 'a label

For Loopie = 0 to 100 step 1 '100 steps from off to bright

brightness=255-loopie

pwmout c.2, brightness, loopie 'light the LED

pause Dlay

next loopie

for loopie = 100 to 0 step -1 'repeat above backwards

brightness=255-loopie

pwmout c.2, brightness,loopie

sertxd (#loopie, " ")

pause Dlay

next loopie

return 'return to the point where the routine was called

LongFlash: 'do the longer flash

For Loopie = 0 to 255 step 1 '255 steps from off to bright

brightness=255-loopie

pwmout c.2, brightness, loopie

pause Dlay

next loopie

for loopie = 255 to 0 step -1 'repeat above backwards

brightness=255-loopie

pwmout c.2, brightness,loopie

pause Dlay

next loopie

return

6060

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PICAXE ArticlePICAXE Article

Morse Codebeacon

6161

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PICAXE ArticlePICAXE Article

• Article #2 includes:– Working with multiple LEDs (up to 6)– Working with trigger inputs– Working with variable inputs (potentiometer)– Lots of projects / programs

6262

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Article #2Article #2Custom Circuit BoardCustom Circuit Board

• I designed and had boards fabricated that support– up to 6 LEDs– 2 trigger switches – 2 potentiometers– 6 power transistors– 5 volt regulator

6363

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Article #2 - ProgramsArticle #2 - Programs

• Crossing signal with two triggers

• Traffic light

• Emergency vehicle lights

• High power LED ditch lights

• School bus strobe light

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PICAXE ArticlePICAXE Article

• Article #3 to include:– Moving animations with servos– Controlling motors

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AnimationAnimation

• Animation adds fun and excitement to your layout

• Moving things is easy with the PICAXE as it knows how to talk to model airplane servos

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AnimationAnimation• By sending precisely timed pulses the

PICAXE can set the servo’s arm to a specific position and hold it there.

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AnimationAnimation• Only three wires go to the servo

– Two for power and 1 for control pulses– The SERVO command is built into the

PICAXE

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PICAXE PIC68

Simple Servo ProgramSimple Servo Program'd. bodnar 6-2-13 'Servo Demo

symbol ServoPin = 5b2=225:b3=75 ‘the range is 75 to 225

start: gosub cw: pause 1000: gosub ccw: pause 1000: low ServoPingoto start

cw:for b0= b2 to b3 step -1 servo ServoPin, b0 pause 50next b0return

ccw:for b0=b3 to b2 step 1 servo ServoPin, b0 pause 10next b0return

6969

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Servo ExamplesServo Examples

• Elephant used at Children’s Hospital

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AnimationAnimation• Playmobil elephant from Pittsburgh’s

Children’s Hospital layout

7171

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Servo ExamplesServo Examples

• Outhouse

7272

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Servo ExamplesServo Examples

• Water Spout

7373

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Servo ExamplesServo Examples• Prairie Dogs

7474

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Servo ExamplesServo Examples

• Scanning Spotlight

• Uses brightLED

• And twoServos

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Servo ExamplesServo Examples

• Bears– Two servos on large

bear– One each on others

7676

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Servo ExamplesServo Examples

• Eggliner

7777

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Servo ExamplesServo Examples• Children’s Hospital Searchlight

– Rotates back & forth via servo– Only works when train is running and lights

are dim

7878

PICAXE PIC78

Servos Come in Many SizesServos Come in Many Sizes

• Standard

• 9 gram

• 4.3 gram

• 1.5 gram

7979

PICAXE PIC79

Tip - MPJA Power SupplyTip - MPJA Power Supply

• Excellent tool for testing circuits

• Also works well for testing locomotive and other train related devices

• Dual meters (volts / amps) provide very valuable information

8080

PICAXE PIC80

Pendulum AnimationPendulum Animation• An acrobat is

substituted for the pendulum

• A microcontroller starts & stops the acrobat and changes the speed of his swinging

• A very simple circuit operates our last animation

• The pendulum swings because of a magnet at the bottom & a coil under the base that gives a shove each time it goes by

8181

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Tip – Learn to Solder!Tip – Learn to Solder!

• With some practice and the right tools you can be an expert in no time!

8282

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Tip - SolderingTip - Soldering• A good iron makes you a better solderer!

– MPJA.com

– Item #ZD 929C – $46.95– Digital

temperature readout

– Replacement handle assembly $6.95

8383

PICAXE PIC83

Tip - SolderingTip - Soldering• A clean tip makes all the difference.• http://www.dealextreme.com

• Item 34154 • $6.65• MPJA has something

similar

8484

PICAXE PIC84

Tip - Tip - Plumber’s PuttyPlumber’s Putty

• I find Plumber’s Putty to be ideal for holding parts while I solder them

• Easy to remove and reasonably inert

8585

PICAXE PIC85

Speaking of Soldering ThingsSpeaking of Soldering Things

• Torch - # 42099from Harbor Freight

• Typically less than $10

• Frequently on salefor ½ of that

8686

PICAXE PIC86

#1 Tip EVER - Adhesive#1 Tip EVER - Adhesive

Great for quick temporary or permanent connections– Similar to the “goo” on the

back of a new credit card– I use it in place of hot melt

glue– DOTS brand– Michaels (don’t forget the

40% off coupon!)

8787

PICAXE PIC87

Sound adds to Animations!Sound adds to Animations!• Inexpensive sound cards can play back your own

sound files• plugs directly into a computer's USB port for sound

downloads • utilizes the most

common type of sound files, MP3's

• costs about $13.00

http://www.trainelectronics.com/MP3_USB/

8888

PICAXE PIC88

USB / MP3 SystemUSB / MP3 System• records up to 75 seconds of sound • Easily connects to external speaker systems • Easily triggered by a push button, reed switches or

radio control systems• Notes on use on

trainelectronics.com

http://www.trainelectronics.com/MP3_USB/

8989

PICAXE PIC89

Newer USB / MP3 SystemNewer USB / MP3 System• Records up to 300

seconds of sound • Direct connection to

external speaker systems • Easily triggered by a push

button, reed switches or radio control systems

• Has 4 separate triggers for 4 different sounds

• About $16.00

http://www.trainelectronics.com/USB_sound_4/

9090

PICAXE PIC90

Laser SensorLaser Sensor

• Although reed switches and magnets work well as sensors …

• … we sometimes need something more capable

• … like a laser shining down or across the track to detect a train

• … just like those that protect bank vaults in the movies!

9191

PICAXE PIC91

Laser SensorsLaser Sensors• Sensors at each end of the module’s main

line were used to stop the mining train when a train on the main line approached

• They worked most of the time but could easily be tricked

main main

mining

mining

9292

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Laser SensorsLaser Sensors

•A redesign has a laser beam shooting right down the center of the main line•Any train on the main interrupts the laser beam

9393

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Laser SensorsLaser Sensors

• The only problem that remained was the bright laser light that was quite visible as it was shining on the train & its cars

• … not too prototypical!

• Since a microcontroller was in charge of the laser being on or off some experiments were in order

9494

PICAXE PIC94

Laser SensorLaser Sensor

• Designing such a system is pretty easy using a photo transistor and a laser

• … but the laser “dot” is rather visible and distracting and may be harmful to visitors or pets!

9595

PICAXE PIC95

Laser SensorsLaser Sensors

sensor laser

• I decided to redo the circuit putting a microcontroller in charge of the laser.

• I started doing some experiments having the PICAXE turn the laser on and off

• … figuring it would be better

• … but it was even more visible when flashing!

9696

PICAXE PIC96

Laser SensorsLaser Sensors• The length of “on” time was gradually decreased• I was hoping that the sensor would still detect

brief laser light pulses• 1/10 second on / 1/100 second off

– OK

• 1/100 second on / 1/100 second off– OK

• 1/1000 second on / 1/100 second off – still OK!

9797

PICAXE PIC97

Laser SensorsLaser Sensors

• The time was decreased till it hit the fastest pulse that the controller could produce – less than 1/10,000 second

• Still OK

• And….

• It produced a nearly invisible laser beam

9898

PICAXE PIC98

Laser SensorsLaser Sensors

Top:

HIGH laser ‘turn on laser

PAUSEUS 1 ‘pause 1/1,000,000 second

IF PhotoTran=1 THEN ‘if detected then do stuff

HIGH led1:HIGH relay ‘LED & RELAY on

ELSE ‘if not do other stuff

LOW led1:LOW relay ‘LED & Relay off

ENDIF

IF SWBright=1 THEN LOW laser 'if switch on dim Laser else leave on full

PAUSE 10 ‘leave laser off 1/10 second

GOTO Top ‘do it again

9999

PICAXE PIC99

Laser SensorsLaser Sensors

• A switch was added to keep the laser on at full brightness while aiming the laser and aligning it with the sensor…

• … making setup-alignment a snap!

100100

PICAXE PIC100

Laser SensorsLaser Sensors

• It even works with a mirror on the other side of the track reflecting the laser dot back to the sensor

101101

PICAXE PIC101

18 Pin PICAXE Chip18 Pin PICAXE Chip

• Prior seminars focused on the PICAXE 08M - 8 pins – about $3.00 each

• A new 18 pin chip, the PICAXE 18M2 -about $5.00 and has much more capability– Faster– 15 pins available for input & output– Much more memory– Low voltage operation (as low as 2 volts!)– Built in timer

102102

PICAXE PIC102

18 Pin PICAXE Project18 Pin PICAXE Project

• We will be using the new PICAXE chip to create a completely solid state track side or on-board speed controller…

• …that has a really cool trick up its sleeve…

• …that can be modified to do a host of other things

• …that can be modified to supply up to 12 amps of DC power!

103103

PICAXE PIC103

PICAXE Speed ControllerPICAXE Speed Controller

• Objectives:– Controls DC track power: speed & direction– Manages smooth acceleration / deceleration– Never changes direction when power is on– Controlled by inexpensive television IR remote

control– Can handle several amps

104104

PICAXE PIC104

Speed ControllerSpeed Controller

• Parts:– PICAXE 18M2– Single chip “H-Bridge”– IR Receiver chip– 18+ volt power supply

105105

PICAXE PIC105

Speed ControllerSpeed Controller

• Other circuits use relays to reverse direction and a single transistor to control speed

• This circuit uses a single L298N to do both jobs

106106

PICAXE PIC106

Speed ControllerSpeed Controller• The first version of the controller operates

a simple layout using the IR remote control to vary track power

• It can be used as a basic speed / direction controller

• …or it can be programmed to change direction based on time (easy point-to-point controller!)

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How Do We Control the Controller?How Do We Control the Controller?

• Speed and other settings can be modified with a simple TV remote control

– Set min & max speed– Set rate of deceleration– Set time to wait at ends on point-to-point

& IR sensor

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IR Control Built into PICAXEIR Control Built into PICAXE

• PICAXE program to display IR codesSymbol IRSense = b.2 'pin 8

Symbol InfraRED = b12

#TERMINAL 4800

IRTEST:

Irin [50, IRTEST],IrSense, InfraRED

SERTXD("InfraRED Code = ",#InfraRED,13,10)

GOTO IRTEST

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Control OptionsControl Options• Remote Control Buttons

– Channel UP - Increase speed – Channel DOWN - Decrease speed – Volume UP - Change direction to forward (if not

already going forward) – Volume DOWN - Change direction to backwards (if

not already going backwards) – MENU - stop the train remembering the current

speed - press MENU again to restart at the same speed and in the same direction

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Additional Control OptionsAdditional Control Options

– Press the RETURN button to change settings1. Change Maximum Speed

2. Change Minimum Speed

3. Change Run Time

4. Change Acceleration / Deceleration rate

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Train RecorderTrain Recorder• One day I had an idea.

• Rather than entering places to have the trolley stop with the TV remote…

• … wouldn’t it be cool if it could be programmed to learn the route that I wanted it to take?

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Train RecorderTrain Recorder• I tried it and it worked…

• … giving birth to the most exciting version that automatically records (at a rate of 50 recordings per second) a train’s movements so that you can play them back over & over

• Total record time of up to 20 minutes

• A rather unusual but very cool thing to do!

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Train RecorderTrain Recorder

• Additional Components:– A memory chip to store activity (can store up

to 20 minutes!)– A potentiometer to control speed & direction– A relay to control a “stop block” that keeps

things in “sync”

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LED Coach LightsLED Coach Lights

• I recently received an email from a garden railroader who wanted to illuminate his passenger cars with battery powered LEDs

• After some discussion and experimentation a solution was designed that provides us with many options for using and powering LED lighting

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Prewired LED Strip LightsPrewired LED Strip Lights• Meant for under cabinet lighting in

kitchens and similar applications

• 12 volts

• Can be cut into short sections

• Many colors available

• Self adhesive back

• A great product but not for his low voltage application!

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LED Coach LightsLED Coach Lights

• Design called for battery operation and enough lights to illuminate g-scale coaches

• First units were built on popsicle sticks to get layout and spacing right

• All of the LEDs are wired in parallel to keep operating voltage down

• Adding parallel resistors increases brightness & decreases run time

100 ohm resistors

Resistance (ohms)

mA to LEDsHours /w 2000 mAh cells

one 100 20 100

two 50 40 50

three 33.3 60 33.3

four 25 80 25

five 20 90 20

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LED Coach LightsLED Coach Lights

• Lights can be turned on and off by a latching reed switch

• Pass a magnet over one end of the reed switch and the LEDs go on

• Pass it over the other end and they go off

• The reed switch can be placed against the top of the car so nothing is seen and no holes are drilled in the car

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LED Coach LightsLED Coach Lights

• A custom circuit board was designed

• And sent off for manufacture

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LED Coach LightsLED Coach Lights• The circuit board

– Is about 13” long

– can accommodate • up to 25 LEDs• a latching reed switch• current limiting resistor

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Tip – CA AcceleratorTip – CA Accelerator

Most of us have used cyanoacrylic glue (super glue)

But have you also used CA accelerator which dries CA in seconds?

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LED Coach Lights Power OptionsLED Coach Lights Power Options

• A power board was added that accommodates track power – DC or DCC– Bridge rectifier – gives consistent polarity– Voltage regulator- gives consistent 5 volts– Capacitors – no flicker on dirty track

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LED Coach Lights with Super Caps!LED Coach Lights with Super Caps!

• Super Caps can keep lights going for minutes after the power is removed

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LED Coach Lights with DCC PowerLED Coach Lights with DCC Power

• The circuit was modified to put groups of LEDs in series to accommodate higher voltages such as from DCC

• The power supply board was modified as well

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It’s more fun to make it yourself than to buy it ready to go!

"I am always doing that which I "I am always doing that which I cannot do, in order that I may cannot do, in order that I may learn how to do it."learn how to do it."Pablo PicassoPablo Picasso

Remember:

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Your Ideas?Your Ideas?

• Questions?

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