Race Photogate

Two sets of timing gates for racing cars in a school solar car challenge that track and report the speed of each car in each of two lanes.

Jun 8, 2019

6479 views

4 respects

Components and supplies

1

Through Hole Resistor, 2k ohm

4

Photo transistor light sensor

1

HC-05 Bluetooth Module

1

Tiny Breadboard

1

Android device

1

1/2" PVC pipe and connectors

1

Alphanumeric LCD, 16 x 2

5

Through Hole Resistor, 200 kohm

4

Jumper wires (generic)

16

Neodymium Disc Magnets

4

Male/Female Jumper Wires

4

High Brightness LED, White

1

Arduino UNO

4

5V 650nm 5mW Red Dot Diode Laser Head Red Laser Diode 6mm Red Laser Diode Laser Head

Tools and machines

1

Soldering iron (generic)

1

Quick setting epoxy resin

1

3D Printer (generic)

1

Solder Wire, Lead Free

1

Hot glue gun (generic)

1

Gorilla Glue

Apps and platforms

1

MIT App Inventor 2

Project description

Code

Solar Car Challenge (optional phone app for Bluetooth connection)

scheme

MIT App Inventor Code (.aia) for Android Phone to see photogate results via Bluetooth and to reset photogate

Laser_Photogate-2_lanes

arduino

Code to calibrate lasers, time, display results and send them via optional Bluetooth module

Laser_Photogate-2_lanes

arduino

Code to calibrate lasers, time, display results and send them via optional Bluetooth module

Solar Car Challenge (optional phone app for Bluetooth connection)

scheme

MIT App Inventor Code (.aia) for Android Phone to see photogate results via Bluetooth and to reset photogate

Downloadable files

Laser Photogate 2 Lane Schematic

Laser Photogate Schematic for 2 Lanes

Laser Photogate 2 Lane Schematic

Laser Photogate 2 Lane Schematic

Laser Photogate Schematic for 2 Lanes

Laser Photogate 2 Lane Schematic

Documentation

PVC protective wedge

An optional triangular wedge can be made to prevent any car from sideswiping the center laser base of the final photogate--either from wood or with this 3D printed version.

PVC protective wedge

PVC protective wedge

An optional triangular wedge can be made to prevent any car from sideswiping the center laser base of the final photogate--either from wood or with this 3D printed version.

PVC protective wedge

LCD screen cover

An optional cover for the enclosure with mounting posts for a 16x2 Arduino LCD screen.

LCD screen cover

Comments

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Anonymous user

5 years ago

Nice project. One quibble. The specification for a 3D printer is kind of a barrier to adoption for many people. I now understand it's optional, but I would stress that in the subtitle "Necessary tools and machines." I almost skipped over the project.