Introduction

This is the first kit on the «Robotics» shelf. A robot vacuum drives around a room on its own: it bumps into a chair leg — backs off, turns, drives on; and smarter models notice a wall in advance and turn without touching. There is no programmer nearby — sensors and logic decide everything. In this kit you build such a robot: a two-wheeled chassis, a bumper, an ultrasonic range finder and logic on CMOS 4000 chips — without a single line of program.

• lesson 1 — the chassis: two wheels, no steering — a turn comes from the difference of the wheels;
• lesson 2 — the «bug»: a bumper and the CD4017 counter — bumped, backed off, turned;
• lesson 3 — ultrasound: echo time is centimetres, the CD4029 counter and a display;
• lesson 4 — without touching: closer than 20 cm — the CD4585 comparator starts the same manoeuvre;
• lesson 5 — along the line: two line sensors and three tracks.

What you need

The chips are ready-made: the kit file robot-chips.json, imported into the library with one button. These are real Texas Instruments chips — CD4017, CD4029, CD4585 and others — with the same pin names as in the datasheet; inside each are gates and transistors after the TI logic diagram (how they are built — in the «How Things Work» kits). Here we do not build them but use them: labels go on the pins, double-click a pin.

The mechanics — the Mechanics button and the Sensors menu: paper, contour, obstacle, chassis, pen, bumper, ultrasound, line sensor.

How big it is

The robot of lessons 1–4 — 15 chips with 2,800 transistors inside. The line follower (lesson 5) — 2 chips.

Mode

Build and check in Fast mode: the centimetre counter needs every tick of the 8 kHz clock, and in Real the editor cannot keep up with 16,000 evaluations a second.