Arduino Hot Wheels Speed Track - Part 1 - Prototype

It should be no surprise that my son loves hot wheels and racing his cars all over the house!

One of his favourite things to do is to race off all of his cars (over 100 now) to determine which is the fastest car.

Right now he does it all by eye, and often one car will start faster than another car, throwing off the results, so I thought it would be a fun and challenging project to build him an Arduino based speed track finish line timer that he could use to both record each cars speed and determine the winner of each heat.

In this video, we will quickly go over the design and them jump into building the project on breadboards.

Step 1: The Concept...

The concept is pretty straight forward. Two tracks side by side, with a starting bridge and a finish line bridge.

The cars race through the start, triggering each tracks starting IR sensor and the timers for each car.

Once the cars hit the finish line each IR sensor picks up the complete state and records the time and then flashes the winning time on the display.

Step 2: Collecting All of the Parts

You will need the following parts...

2x Arduino Nano R3
2x bluetooth hc-05 module
1x momentary switch
1x 8 digit 7 segment display
1x 330 ohm Resistor
2x 2.2k ohm Resistors
2x 4.7k ohm Resistors
4x IR obstacle avoidance module
2x Full Size Solder-less Breadboard
A whole bunch of breadboard wire ;)

Once you have them all together, seperate them out based on what you need for each breadboard

Step 3: Add the Components and Complete the Wiring

Add all of the components onto each breadboard following the step by step instructions in the video

Once all components are in place, wire it all together

Connect the VCC and GND rails for all components that require power
Connect the OUT pins of the IR Sensors to D2 and D3 on each Breadboard
Connect a wire from the BUTTON to the VCC rail
Connect a wire from the GND side of the button to D8
Connect a wire from the Anode side of the LED to A0
Ensure that the GND of the LED is connected to the GND rail
Connect a wire from TX pin on each NANO to the "starting" end of the 4.7K resistors on each breadboard
Connect a wire from between the 2.2K and 4.7K resistor to the RX pin on each BT module
Connect a wire from the RX pin on each NANO to the TX pin on each BT module
Connect the CLK pin of the display to D4 on the NANO
Connect the CS pin of the display to D5 on the NANO
Connect the DATA pin of the display to D6 on the NANO