Assembly - Traffic Light

What you will need

• Traffic light components (Duckietown project shop)

• An appropriately configured SD-card.

• Tools: (strong) wood glue or hot glue gun, tape, double-sided tape.

What you will get

• An assembled traffic light in configuration DT21-TL (latest) or previous legacy versions.

This section describes the physical assembly and installation of traffic lights.

Overview

Traffic lights are crucial elements of modern cities, and in Duckietown, they play a similar role by ensuring well-organized traffic.

They can serve as:

1. Centralized coordinators of traffic at 3- or 4-way intersections in Duckietown.

2. Components of a Duckietown Autolab watchtower network.

Attention

For Duckiebots to recognize traffic lights governing a specific intersection, appropriate signage must be placed (traffic light traffic sign instead of a stop sign).

• Hardware Design: Traffic lights are “Duckiebots without wheels,” housed in a distinct chassis.

• Structure: They consist of two supports connected by an overhanging tube, with one support containing the computational stack and an overseeing camera.

• Placement: Traffic lights are positioned diagonally at intersections.

Hardware Assembly

• For latest configuration traffic lights, refer to the instructions:

  • Assembly - Traffic Light DT21-TL

• For legacy builds (prior to TL21), follow these instructions:

  • Assembly - (Legacy) Traffic Light DT18-TL.

SD-card Image Preparation

At the software level, traffic lights function similarly to Duckiebots. When initializing the SD-card, follow the instructions here, ensuring you use the --type traffic_light option.

Wi-Fi configuration for traffic lights is not set by default. To enable it, use the --wifi option as described in the instructions.

Example command for a Wi-Fi connected traffic light:

dts init_sd_card --hostname watchtowerXX --country COUNTRY --type traffic_light --configuration TL21

Note

For Autolab users: Use the convention hostname: watchtowerXX, where XX are incremental numbers.

• For standard traffic light setup, use:

  • hostname: trafficlightXX

• Default login credentials:

  • Username: duckie

  • Password: quackquack

Warning

For Autolab users, do not change the username and password.

Launch Traffic Lights

By setting the robot_type to traffic_light, blinking behavior will start automatically on boot.

To restart the traffic light behavior manually, run the following inside the duckiebot-interface container:

roslaunch duckiebot_interface all_drivers.launch veh:=NAME robot_type:=traffic_light