Day 12: Wiring and Testing
This is the final day of construction. Today I completed all of the wiring and tested the buttons and outputs using Pinscape.
I used the following methods to help organize the wiring:
- Color coding of wires by function
- Labels on the wires themselves
- Reusable cable ties to bundle cables together
As I already mentioned on previous days, I used some multi-color Dupont ribbon cables for some of the connections. Here is the color coding I established for the rest of the wiring:
- Red is for 5V positive. I used 22 AWG wire for low current and some 14 AWG wire for the high current parts to the DMD.
- White is for 5V ground. I used 22 AWG wire for low current. There are a few occasions where I used 14 AWG black wire for the high current lines. White is also the common for all of the buttons.
- Green is for 3.3V/5V logic. I used 22 AWG wire for the button inputs to the KL25Z.
- Yellow is for 24V positive. I used 18 AWG wire.
- Black is for 24V ground. I used 18 AWG wire. Note that in this case the 5V ground and 24V ground are really common as they both derive from the power brick.
- Blue is for 24V signaling. I used 18 AWG wire for the low side of the outputs.
I wanted to make sure things can be altered or reused in the future so all of the connections were done screw connectors, spade connectors that are crimped to the wire, or molex headers with crimped connectors. No soldering was used.
The following spade connectors were used:
- Contactors – 20 spade 6.3mm males and 20 spade 6.3mm females with plastic sheaths
- Switch 24V LEDs – 4 spade 6.3mm females with plastic sheaths
- Flippers – 8 spade 4.8mm females with plastic sheaths
- Switches – 8 spade 4.8mm females with plastic sheaths
- Switch 5V LEDs – 2 spade 6.3mm females with plastic sheaths
I attached cable ties to the sides of the cabinet. These ones have both a sticky pad and a screw hole. I elected to screw them to the sides to prevent them coming off later when under tension from a wire. The ties can be tightened or loosened as will and do not have to be cut. I organized the ties so that wires from the left side went around clockwise towards the back and wires from the right side went around anticlockwise to the back. This leaves an area in the front with no cabling that is available to be used for future additions to the cabinet.
Before starting with the wiring, I needed to make some simple devices that would attached diodes to the contactors and provide male spade connectors for the wiring. The picture below shows the device. The two bare wires are screwed into the contactor; yellow for 24V positive and blue for negative. Note the orientation of the 1N4007 diode with the cathode (band) connected to the yellow 24V positive side.
Here are the wiring steps I performed:
- Connect yellow common wires to all of the contactors and 24V LEDs. I used two wires, one for the four contactors and LED on the left and the other for the six contactors and LED on the right and center. Each yellow is connected to the 24V positive terminal strip.
- Connect a blue wire to each contactor from the Pinscape power output board with fuses.
- Connect power to the Pinscape power output board with fuses, both 24V (yellow and black), and 5V (red and white)
- Connect white common wires to all of the switches and flippers. I used two wires, one for the five switches on the left and the other for the three on the right. Each white is connected to the ground on the 5V terminal strip.
- Connect a green wire to each switch from the KL25Z. I used a 8-way 0.1” molex header with crimps to insert into the KL25Z.
- Connect a common ground wire between the KL25Z and Pinscape power output board with fuses. This is needed because the KL25Z derives its power from the USB cable. At a later stage this won’t be needed because the KL25Z will be powered from the 5V supply in the cabinet.
- Connect the LED for the “Exit” button to the 5V terminal strip using red and white wires. I ran out of the proper size space connectors to do the “Shift” button but that can added in later. The "Exit" button LED is not under any control and is permanently on.
- Reconnect the outputs between the KL25Z and the power output board with fuses (using an interface board with ULN2803A Darlington transistors)
Here is a picture of the completed wiring inside the cabinet.
The next thing to do is to test the cabling. The Pinscape config tool provides a test feature which is extremely handy for this purpose and allows you to quickly find faults or incorrect cabling. Here are the test steps I performed:
- Test the Pinscape power board with fuses without using the KL25Z. By connecting each input to ground, I could determine if a particular contactor or LED was wired correctly.
- After reattaching the ribbon cables from the KL25Z to the power output board, I could then test each output from the Pinscape config tool. This was very useful because I discovered that two of the Dupont connectors had been swapped.
- Test the switches connected to the KL25Z. This worked correctly and the Pinscape config tool shows which inputs are activated and a nice keyboard diagram when a button is pressed e.g. pressing the left flipper results in the left shift key being highlighted. This even worked with the Shift button functions.
Here is the list of hardware I needed to complete the wiring. Note that I ordered 100 feet reels of wire as they are most cost effective and I can use the remainder on other projects.
- 270Pcs 22-10 AWG Copper Brass Female Male Spade Connectors Wire Crimp Terminals - eBay ($6.66)
- 25x Adjustable Adhesive Cable Straps Cord Management Tie Mount Clips - eBay ($5.25)
- 100 feet stranded 18GA 300V 105C Wire Blue [H318-06-100] - eBay ($11.95)
- 100 feet stranded 18GA 300V 105C Wire Yellow [H318-04-100] - eBay ($11.95)
- 100 feet stranded 22GA 300V 105C Wire Green [H322-05-100] - eBay ($7.95)
- 22GA Red Wire - Free (from parts bin)
- 22GA White Wire - Free (from parts bin)
- Other miscellaneous, crimps etc - Free (from parts bin)
Edited by MikePinball, 06 January 2019 - 08:57 PM.
MikePinball (dba Oak Micros). I have sold a number of electronic boards for virtual pinball cabs such as Pinscape All-in-One, Pinscape Lite, Plunger Kit, Rotary Encoder, Fuse board, Resistor board, Pinball Addressable LEDs (PAL) board, and RGB Flipper/Magnasave board with clear buttons. I am currently taking a break but will continue to support existing customers. See my home page for more details.