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2014 Amherst Railroad Hobby Show. Dave Bodnar January 23, 2014 Amherst, MA. This presentation is available on-line at: www.trainelectronics.com or www.davebodnar.com. Revised 01-20-14. Objectives. Demonstrate various devices & projects that utilize microcontroller operation …
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2014 Amherst RailroadHobby Show Dave Bodnar January 23, 2014 Amherst, MA This presentation isavailable on-line at:www.trainelectronics.com or www.davebodnar.com Revised 01-20-14
Objectives • 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!
Topics to be CoveredPart 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
Topics to be CoveredPart 2 • Animations & other PICAXE based projects • …More Tips, Tricks, Tools • …More new & improved gizmos & gadgets
Working 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!
Working Hypothesis 2 We 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
Working 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!
PICAXE • What can it do? • Intelligently control & automate many aspects of operating your railroad • Operate lights, motors, animations and other electrically powered devices
PICAXE • 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
PICAXE - What You Need • Windows computer with serial port or … USB to serial adapter or … USB programming cable • Windows computer running free PICAXE software • Power source • 3 @ AA cells = 4.5 volts • Note:AxePad software is available for Mac & Linux computers – fewer features than PC software
Tip 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-09260for about $15.00 Details on use at www.trainelectronics.com
Tip • Peter Anderson (PHAnderson.com) has PICAXE chips & accessories • Amazon & eBay – search for PICAXE • SparkFun.com
First Project:Flashing Crossing Lights • Design objectives: • Alternately flash two red LEDs • Operate from battery power • Alter timing and other characteristics from software
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
Tip - Testing LEDs White LEDs are OK for long use at 3+ volts, Red, Green, Amber are not A great use for old watch batteries! • 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
LED 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
Flashing Crossing Lights Parts: Cost: Less than $10.00
Flashing Crossing Lights Software: free from www.picaxe.com
Flashing 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 together Remember: Don’t use a 9 volt battery or 4 fresh 1.5 volt AA cells! 5.5 volts maximum!
Not sure about…??? • A resistor’s value… • Or a battery’s voltage… • Or if a wire is broken… • There is a tool for that!
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
Tip – 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
Tip – 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
Tip – Step Down Voltage Converter • Can easily be modified to use a larger potentiometer • Inexpensive speed control for a small layout
Flashing Crossing Lights Radio Shack board # 276-002 $15.00
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. high 1 ‘turn on LED 1 - pin out1 low 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 out2 goto start: ‘do it again
Flashing Crossing Lights Program 2: modified to flash for 10 seconds and turn off for 10 seconds start: high 1 ‘turn on LED 1 low 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 2 next b0 ‘back to loop low 1 ‘turn LED 1 off low 2 ‘turn LED 2 off pause 10000 ‘stay here 10 seconds goto start: ‘do it again
Flashing Crossing Lights • Program simulation is built in! • You can write and test programs without any hardware… • Give it a try tonight!
Flashing Crossing Lights Hardware modification for button or reed switch activation:
Flashing Crossing Lights Program 3: modified to flash 5 seconds on each button push start: low 1 ‘turn off LED 1 low 2 ‘turn off LED 2 if pin3 = 1 then start: ‘if switch off go to top flash: high 1 ‘LED 1 on low 2 ‘LED 2 off for 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 loops goto start: ‘start from very top
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. Sensor 2 Sensor 1
Flashing Crossing Lights Program 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
Tip - Reed Switches • Two small metal plates touch when near a magnet closing acircuit • Contained withina glass vial – VERY Fragile! • Many sizes available
Tip – Magnets for Reed Switches • Deal Extreme 10mm x 1mm Magnets (part #13516) • Very strong – 100 for $12.80 delivered!
Tip – Magnets for Reed Switches • Harbor Freight magnets
Tip – Magnets for Reed Switches • SunTekStore magnets
Tip - 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!
Tip – 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
Latching 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
Tip - Connectors We are always looking for ways to connect electrical devices together • For low currentuse: • Deal Extreme item # 15234 • $2.99 for 10pair includingshipping!
Tip – Connectors • Connectors: • High current fortrack and batteryconnections: • Deal Extreme item # 10788 • $6.37 for 10pair includingshipping!
Tip – 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 extensionshttp://www.ebay.com/itm/10pcs-150mm-Servo-Extension-Lead-Wire-Cable-For-Futaba-JR-/151082981725?pt=Radio_Control_Parts_Accessories&hash=item232d3f595d
Tip – Connectors • Multi pin cables with sockets • Great for connecting cars to one another, tenders to locos, etc • Available in 2 pin 8 pin
Tip – Connectors • Search eBay for jst 1.25to find the smallest connectors
Tip – 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
Tip – Dubro Collars • Ideal for connecting to motor shafts & to join piano wire for servos • http://shop.dubro.com/c/aircraft_collars
Tip – 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!
Garden Railways PICAXE Article April 2013 Issuepages 54-59 Contains a detailed introduction to the PICAXE and several projects