RESEARCH & TOOLS / LINE-FOLLOWER LAYOUT

TrailFollow the path from idea to understanding.

Trail is a teaching layout for a small two-wheel robot with downward-facing sensors. Explore its circuit and drive behavior, then adapt the included range-based stop controller as a virtual API exercise.

Build with Trail Explore the design

Includes assembly, starter wiring and executable virtual JavaScript.

ASSEMBLY PREVIEW/LINE

Trail · Line-follower layout concept illustration; the 3D preview uses the actual preset geometry

Static illustration · loading 3D

Orbit the actual starter assembly. Open the workbench to edit or run it.

16components

32starter connections

1.25 kgestimated component mass

ESP32-C3control platform

Trail · Line-follower layout, an illustrated research & tools assembly

Concept illustration · inspect actual geometry above.

A COMPLETE STARTING POINT

Get to know
what's inside.

A two-wheel teaching robot with a downward sensor layout. All 16 components and 32 starter connections remain editable in your own project.

Robotics educationDownward sensor layoutsSmall drive systems

View the included component types

Rover chassis
2S battery · 2.2 Ah
5 V buck regulator
ESP32-C3 compact · virtual controller
Emoji OLED display
Dual H-bridge
Geared DC motor · 35:1
Rubber wheel · 90 mm
Ball caster
Forward range sensor
6-axis IMU
Wheel encoder
Line-following array · 8 channels

YOUR FIRST THREE EXPERIMENTS

Build understanding.
One change at a time.

Use the starting assembly to ask better questions about your design. Save a copy, change a parameter and compare what happens.

Inspect the design

Find the downward sensor positions and inspect their circuit connections.

Try a change

Run the supplied range-based stop controller and adjust its threshold.

Compare and learn

Compare the ESP32-C3 layout with the ESP32 rover starter.

line-follower.jsVIRTUAL API

function step(robot) {
  robot.drive(0, 0);
  if (robot.brownout || robot.battery.voltage < 6.25) { robot.display('🪫'); return; }
  const range = robot.sensors.range;
  if (!Number.isFinite(range)) { robot.display('⚠️'); return; }
  const obstacle = range < 0.65;
  robot.drive(obstacle ? -0.3 : 0.35, obstacle ? 0.35 : 0.35);
  robot.display(obstacle ? '🤔' : '😊');
}

The full, editable starter script is included in the workbench.

KNOW WHAT YOU'RE TESTING