Contents

1. Introduction
2. A little history
3. Lesson 1. The chassis: two wheels
   1. 1.1. Idea: no steering wheel — just two wheels
   2. 1.2. Idea: four moves
   3. 1.3. Idea: the arena
   4. 1.4. Build
   5. 1.5. Check
   6. Lesson 1 paste (Cmd+I)
4. Lesson 2. The «bug»: a bumper and the CD4017
   1. 2.1. Idea: a manoeuvre is a sequence of steps
   2. 2.2. Idea: wait for a bump — HOLD
   3. 2.3. Idea: which wheel goes which way — LDIR and RDIR
   4. 2.4. Build
   5. 2.5. Check
   6. Lesson 2 paste (Cmd+I)
5. Lesson 3. Ultrasound: centimetres on the display
   1. 3.1. Idea: time is distance
   2. 3.2. Idea: a measurement is a sequence of steps
   3. 3.3. Idea: the centimetre counter — two CD4029s
   4. 3.4. Idea: when to count — CIU
   5. 3.5. Idea: «full» — FULL
   6. 3.6. Idea: the echo in step with the clock — ECHOS
   7. 3.7. Idea: a display that does not flicker
   8. 3.8. Build
   9. 3.9. Check
   10. Lesson 3 paste (Cmd+I)
6. Lesson 4. Without touching: closer than 20 cm
   1. 4.1. Idea: «closer than 20 cm» — compare the tens — CLOSE
   2. 4.2. Idea: remember at the show step — NEAR
   3. 4.3. Idea: a bump or close — TRIP
   4. 4.4. Build
   5. 4.5. Check
   6. Lesson 4 paste (Cmd+I)
7. Lesson 5. Along the line
   1. 5.1. Idea: the line sensor
   2. 5.2. Idea: drifted off — steer back
   3. 5.3. Idea: L_ON — and the GO switch too
   4. 5.4. Idea: why the tracks look like this
   5. 5.5. Build
   6. 5.6. Check
   7. Lesson 5 paste (Cmd+I)
8. Summary
9. All the parts
10. Instructions in pictures