HARDWARE LAB 01 · INPUT INTERFACES

Controller Signal Analyzer

Operate one virtual controller, then follow the same physical action through four generations of electrical and digital interfaces.

01FINGER02SWITCH / POT03VOLTAGE04DECODER05GAME INPUT

01 / PARALLEL

One wire per control

A switch connects its signal wire to ground. Pull-up resistors make every released line read HIGH.

PHYSICAL SIDE

Generic test controller

LIVE

X AXIS +0%Y AXIS +0%

Tap or click to latch a control; tap again or use Release all to clear it. Keyboard is momentary: WASD / arrows · J=A · K=B · U=X · I=Y · Q=L · E=R · Enter=Start · Shift=Select

DB-STYLE CONNECTOR

Active-low pin voltages

Pin	Switch	Logic	Meter
1	UP	`1` HIGH / released	5.00 V
2	DOWN	`1` HIGH / released	5.00 V
3	LEFT	`1` HIGH / released	5.00 V
4	RIGHT	`1` HIGH / released	5.00 V
5	A	`1` HIGH / released	5.00 V
6	B	`1` HIGH / released	5.00 V
7	START	`1` HIGH / released	5.00 V
8	SELECT	`1` HIGH / released	5.00 V

Why backwards? Each input has a pull-up resistor. Closing a switch gives current a path to ground, so a press is logic 0.

CAPTURE BUFFER · 1/96 SAMPLES

Logic analyzer

INDEPENDENT EXPLORATION

Change the decoder

POLLING RATE 125 Hz8.00 ms between host readsADC RESOLUTIONMore bits provide finer voltage steps, not necessarily less noise.STICK DEAD ZONE 12%Values inside this center window are reported as zero.AUTO POLLContinuously sample at the configured simulated rate.

BENCH CHALLENGE · PARALLEL

Two wires low

Hold UP and A, then test. Both active-low input pins should read 0.

EXPECTEDUP=0 and A=0

Build the target signal, then test it.

TECHNOLOGY BOUNDARY

What changes between generations?

PARALLEL

Wire count

Fast and simple, but every control needs a dedicated conductor and input pin.

SERIAL

Timing

A shift register saves cable wires by making the console ask for each bit in order.

ANALOG

Quantization

Continuous voltage gains precision, calibration, noise, and a numerical conversion step.

HID

Protocol

Device firmware describes a packet so many controller layouts can share one host interface.