Track sensors

We need to add the sensors under the track for the start line.  

Also we will be adding a sensor so that we have a pit area ( a stretch of track) rather than trying to stop ON the start line.

the sensor receivers are small and we have to hookup wires to them. 

Next we twist the wires together (I didnt want to solder and risk ruining the sensors

cover the wire joint with heat shrink tubing and ...

apply heat to shrink the tubing. 

This results in a pretty good joint.

Do the same for the Infrared LED.

The Infrared LED emits the light that the sensor picks up and the beam gets broken by the paddle under the car that fits into to slot in the track and guides the car.

Now both the sensor and Infrared LED are ready for the track

I had initially come up with a design for sensor mounts and printed them on a 3d printer.  

The tube is there to keep the left and right mount aligned and was to be removed.

The mounts cause the sensors to be far enough away from the track so as it would not reliably count all the laps. It was only about 1 mm difference, but it makes a difference.

Not using the sensor mount made the IR Sensor and IR LED as close to the track service as possible.

I could not get a better side view but it looks like the car slot paddle might NOT break the beam totally.  I guess we'll see as soon as we hook it up and try.

Continuing on, I drew a line where the sensors would be:

And removed the plastic with a Dremel.

Next I hot glued the sensor and IR LED to each side of the slot

There may still be an issue with the beam being reliably broken by the paddle (denoted by the poorly drawn green arrow

I wired all the components together so we can more easily mount under the track

To the main controller board

Outlet strips

One fact that was apparent was that we needed outlet strips without a long thick cable.

First open the outlet strip.

Next cut the wires and resolder the wires.

Put it back together and viola, an outlet strip that will fit into

The power supply drawer where space is at a premium.  Plus, you don't want some useless cable rolled up in the drawer

Connectors

I wanted to make the connection to each screw terminal block more secure than just inserting the wire and screwing it down. 

I used soldered spade/fork connectors. 

First step was to measure the wire.

I wanted to avoid large loops of wire for much the same reason as I shortened the outlet strip power cables.

Strip off 5 mm or so of the insulation

Next we will tinn the ends of the stranded wires

You heat up the wire and allow solder to melt and flow between the strands.  This allows the solder to flow more freely when we solder the spade/fork connectors later.

For connecting to terminal blocks? We will use the spade/fork connector.

put the connector into to crimpers.

Crimp

Next, we are going to solder the connector to add strength.  Put it into the alligator clips of the holder in prep for soldering.

Solder.  Since we tinned the ends, the solder will flow more freely.

A solid connector.

Terminal Blocks

I used terminal blocks anytime we had to wire to or from an external device.

Yikes, can't follow the wiring. 

Wires just hanging from the bottom of the track didn't help things.

One of the problems with the wiring we replaced was that wire were going directly from the Arduino controller to external spots.  This made it difficult to move or remove the Arduino.  Now, if you have to move, there is generally enough slack in the cables to move the controller board to a better location 

Note:  I only had larger terminal blocks so don't slight me for the over abundance of terminal blocks.

Setting up my work area

Note:  Please feel free to comment on anything here.  It has been 50 years since I did any soldering as a Boy scout working on the Electronics merit badge.  I also like comments - productive comments that is.

I was having such a good time with the wiring; I decided I should post some pics.

If this looks like fun for you, let me know and you can help out,

I bought a bunch of new stuff to setup my work area for wiring:

• Crimpers
• Soldering Iron
• shrink tubing
• Wire - assorted colors
• Dupont connectors
• Alfred E. Neuman

The bear pic was hung over my bed when I was young so ...

Drawing the wiring layout

First, I layed out all of the components on a board underneath the track that can be pulled outside the track for easier working.  One of the problems with the last version of the wiring is that it was tied to the track with small gauge wire and could not be moved because it was attached to the track above.

You literally had to go under the track and stick your head in the foot between the track and the circular wiring board.  I moved all the track components to the board and made the connections there

I took a picture of the component layout and drew the wiring from there.  I figured out the 

• Length 
• Quantity
• Gauge -18 ga. for power and 24 gauge for internal Arduino wiring
• Connectors

and worked from there.  

Since the track is in the club, and my work area for this portion of the project is at my house (about 200 meters away) I measured the wires in order that we get the cable routed most efficiently.