BenchChapter 10: Meshes

B80MAGNITUDE

The task

P0 reads a signal on CH1 that swings around 50 percent. P1 is a PWM pin on the base of Q1.

Q1 inverts, and R3 and C1 smooth its collector onto CH2.

Make CH2 show twice the distance from 50, so it rises on both halves of the swing.

The board

The chip's ports, each with its kind and the parts its signal reaches. Cyan reads, lemon writes. On a narrow screen, scroll the board sideways to see all of it.

Sources: V1 2 V sine at 5 Hz, V2 2.5 V, and V3 5 V
Resistors: R1 4.7 kΩ, R2 220 Ω, and R3 10 kΩ
Capacitors: C1 1 µF
Transistors: Q1, an NPN transistor
Probes: CH1 and CH2

Key idea

Subtract 50, and flip the sign of a positive result: now it is minus the distance.

Hints

Each hint goes a step further than the one before. Open them one at a time.

Hint 1Show

Doubled, that is at most 80. Since Q1 inverts, the duty is 100 minus the doubled distance.

Hint 2Show

SUB 50, JL past a NEG, then MUL 2 and ADD 100.

Solution

Reveal the Full SolutionThe complete program for MAGNITUDE. Open it only when you want the answer.

The reference program

The game's own solution. It passes every test and scores exactly par on every benchmark.

A full wave rectifier in code, inverted for Q1.

u1SC-2 standard

IN P0
SUB 50
JL N
NEG
N: MUL 2
ADD 100
OUT P1

CYCLES: 2000; at par
ENERGY: 4000; at par
NODES: 1; at par
INSTRUCTIONS: 7; at par