=== Aims ===
 * redo all internal wiring and logic, except the refrigeration parts
 * make the machine more safe by doing things properly and reducing the voltage of exposed components
 * keep the software interface as simple or more simple than before
 * make the buttons on the front of the machine work for dispense
 * make it extensible so things can be added on
 * give the machine a general service where necessary (seals, rust protection, oil)

=== Draft Bill of Materials ===

||Amount||Item||Use||Model||Unit Cost||Total||
||7 (./) ||microswitches||front button switches, 2.21N || [[http://au.element14.com/honeywell-s-c/v7-1v19e9/micro-switch-pin-plunger-spdt-21a/dp/1796579|au.element14.com]] || $2.16|| $15.12||
||20 (./) ||microswitches||each slot has double microswitches, there are 10 slots, 0.15N|| [[http://au.element14.com/honeywell-s-c/v7-5f17d8/micro-switch-pin-plunger-spdt-3a/dp/1796593|au.element14.com]] || $3.60 || $72||
||7 (./) ||5mm round white LED's||replace empty slot globes|| [[http://au.element14.com/vcc-visual-communications-company/vaol-5701wy4/led-5mm-white-1800mcd/dp/1712795|Standard 5mm LEDs, au.element14.com]] White? Or red for empty, green for non-empty? ||0.616 ||$6.16||
||7||resistors||empty slot LED protection|| || < $0.05 || ||
||1||stripboard or veroboard||mount LED resistors|| || || ||
||10 (./) ||4 pin connectors||one for each slot actuator unit|| Molex mini-fit jr series 4way connectors [[http://au.element14.com/multicomp/mc34507/receptacle-free-4way/dp/1578469?Ntt=157-8469 | Also compatible]] || || $31.26 ||
||1 (./) ||9 pin connector||interface with distribution box|| recycle old connector || || free ||
||1 (./) ||manual drop button|| --(reuse old button)-- new button bought from altronics|| || || ||
||1 (./) ||PLC||brain||FMD88-10 starter kit, i-STK88-10, http://www.tri-plc.com/ISTK-FMD88-10.htm (including http://www.triplc.com/fmd8810.htm , software, data cable) || || $475 kit ||
||1 (./) ||PLC expansion card||additional IO||EXP1616R, http://www.triplc.com/exp1616r.htm || || kit ||
||1 (./) ||24V PSU|| kinda need a power supply || [[http://www.automationmart.com/product_info.php?cPath=51&products_id=174&osCsid=1ce326631e601b08c3d427e08036612b| automationmart.com]] || || kit ||
||1 (./) ||5V PSU|| led power and future expansion power || [[http://www.inasolutions.com.au/Shop/ALLOY-DR4505-DIN-Rail-5V5Amp-power-supply-for-Converters-Serial-devices-P1839.aspx|INA Solutions]] ||62.83|| 62.83 ||
||42m (./) ||4 core wire, 1mm minimum diameter (to carry 2A), 18AWG || actuator and empty switch wiring||  http://www.altronics.com.au/index.asp?area=item&id=W3121 || $1.22/m || $51.63||
||11m (./) ||9 core wire || front buttons and lights wiring|| http://www.altronics.com.au/index.asp?area=item&id=W2712 || 43c/m|| $4.72||
||5m (./) ||2 core wire || refrigeration fan power|| http://www.altronics.com.au/index.asp?area=item&id=W2139 || 80c/m|| $4.00||
|| (./) ||reuseable cable ties|| || || Altronics || ||
|| 10m (./) ||cable loom || cable loom for fans and actuators|| http://www.altronics.com.au/index.asp?area=item&id=H3814|| $12.90 || $12.90 ||
|| (./)||terminal blocks|| ||Altronics (see below) || || ||
||3 (./) ||galvanising paint|| recoating everything|| Dy-Mark Zinc Gal from Bunnings || $13.95 || $13.95||
||1 (./) || pack 100 female quick connectors 4.8mm || attach to microswitches || http://www.altronics.com.au/index.asp?area=item&id=H1992A || $11.35 || $11.35 ||
||1 (./) || pack 100 bullet male connectors || cable loom || http://www.altronics.com.au/index.asp?area=item&id=H2152A || $8.13 || $8.13 ||
||1 (./) || pack 100 bullet female connectors || cable loom || http://www.altronics.com.au/index.asp?area=item&id=H2122A || $13.08 || $13.08 ||
||1 (./) || pack 100 terminal pin connectors || terminal block || http://www.altronics.com.au/index.asp?area=item&id=H1902 || $8.34 || $8.34 ||
||1 (./) || pack 10 male quick connectors 4.8mm || fridge fans || http://www.altronics.com.au/index.asp?area=item&id=H1851 || $2.90 || $2.90 ||
||3 (./) ||Fans to replace refrigeration fans|| || 24V [[http://www.altronics.com.au/index.asp?area=item&id=F1160#|Altronics]] || $11.07 || $33.21 ||
||3 (./) ||Finger guards || base refrigeration fan covers|| || $1.09 || $3.27 ||
||12 (./) ||sheet metal screws|| attach fans to cooler cover|| || || ||
||60 (./) ||2mm spacers (washers?)|| otherwise fans will jam on lip of cover|| || || ||
||1 (./) || electrical tape (white) || || || $1.55 || $1.55 ||
||1 (./) ||putty/sealant|| put in corners so water can't sit there and cause rust|| || || ||
|| Total || || || || || ||

=== Internal PLC IO Requirements ===
 * 10x24V DC input for can sensing
 * 7x24V DC input for front door buttons
 * 1x24V DC input for manual dispense mode button
 * 10x110V AC relay outputs
 * 7x 5V DC outputs for empty slot display

=== Process ===
 * empty the machine and bring it into the clubroom. This means everything won't have to be packed up at the end of the day while we're working on it 
 * remove one of the stacks and test a slot actuator to see what it runs off. This determines what hardware we use to drive everything, so we need to know.
 * purchase all required hardware (PLC, wiring, connectors, switches, etc.)
 * write software (state machine based programming implemented in ladder logic, ''should'' be quite trivial)
 * wire up on the bench and test
 * service the machine. A can of zinc spraypaint wouldn't go astray on some of the rust spots I think. Check all the seals. Oil what needs oiling. Clean what needs cleaning.
 * install everything into the machine and test

=== Wiring it up ===

 * Terminal Blocks
  * Earth (green/yellow) doubles as end clamp
  * End cap
  * 3 red - 24V power distribution positive (bridged)
  * 3 black - 24V power distribution ground (bridged)
  * Partition
  * 10 red - slot microswitches positive
  * 10 black - slot microswitch ground (bridged)
  * Partition
  * 10 grey - solenoid active
  * 10 blue - solenoid neutral (bridged)
  * Partition
  * 4 grey - 110V power distribution active (bridged)
  * 4 blue - 100V power distribution neutral (bridged)
  * 2 earth (green/yellow) doubles as end clamp

 * Commoning bars/shorting links (come in strips of ten that you can cut to length)
  * 8 (7 plus one spare)
 * Din rail
  * 2m
 * Slotted duct 3 metres

Total Order:
 * 13 red
 * 13 black
 * 14 grey
 * 14 blue
 * 3 green/yellow
 * 2 end caps
 * 2 end clamps
 * 4 partitions
 * 8 shorting links (2 of each colour)
 * 2m din rail
 * 1 Label set numbers 1 to 50

 * Network cable connection
  * Panduit CFPHS2IW Faceplate or similar
  * Panduit Cat 6 Mech and cable

=== Measured things ===
 * Can drop process: 400ms on, 500ms off, 660ms on, 300VAC peak-to-peak, 1.8A
 * Wire lengths:
  * Actuator units 0,1,2,3: 80cm actuator to wire harness, 210cm harness to corner of machine door, 40cm up door, 45cm across, 40cm up to terminal block (4-core minimum) (16.6m)
  * Actuator units 4,5: 80cm actuator to wire harness, 170cm harness to corner of machine door, 40cm up door, 45cm across, 40cm up to terminal block (4-core minimum) (7.5m)
  * Actuator units 6,7,8,9: 80cm actuator to wire harness, 140cm harness to corner of machine door, 40cm up door, 45cm across, 40cm up to terminal block (4-core minimum) (13.8m)
  * Buttons: 75cm across front of door, 60cm down edge of door, 45cm across, 40cm up to terminal block (8-core minimum) (2.2m)
  * Lights: 75cm across front of door, 60cm down edge of door, 45cm across, 40cm up to terminal block (8-core minimum) (2.2m)
 * The fans suck air through the fridge unit, they don't blow it
 * Plug coming from the back of the distrubution box (red 9 way):
  * Brown/White 110V
  * Blue/White Neutral
  * Red/White 100V


=== Extra Things To Consider ===

 * Snubber circuit for solenoids
  * Something like http://jnf.indiansecurityproducts.info/downloads/Oct06_Vending%20mc.pdf
 * RC snubber component/circuit with 0.1uF (approx 400V rating) and 150 Ohm resistance in parallel with the load should do
  * Need to test this on a breadboard before looking for a permanent way of implementing it

=== Stuff to fix in future ===
 * The 5x1mm washers acting as spacers for the bottom refigeration fans should be replaced with a 5mm spacer or piece of pipe instead - the washers will be impossible to put back on if the fans ever need to be removed
 * --(small can support)-- Done! A small bracket has been made which can fit on any of the front slots. Ask BobAdamson how to use it.
 * coin return magic
 * coin counter
 * more LEDs, not blue
 * redo fan wiring (again)
 * front perspex lights
 * screens
 * button screens
 * --(snack machine keypad, 3 key needs more debouncing)-- Sortof done. BobAdamson pulled it apart and cleaned the contacts. It could probably do with some small capacitors across each button if it keeps happening.
 * documentation and all code up-to-date in ~coke