Maker Faire Lab Ages 8–16 100% virtual

ROB’s Systems Lab presents

Circuit
Quest

Snap in colorful wires, master V = I × R, program an Arduino Uno, then assemble ROB’s 24 V motion, 12 V compute, 48 V arm, USB, CAN, and Ethernet systems all the way to CerebroVisionPro.

See all 90 builds

No tracking and no physical robot connection. Device progress works without an account; optional Apple sign-in privately recalls it.

☀SUN
100%

SOLAR ARRAY

CHARGING84%

LOAD

POWER FLOW4.2 WV = I × R

COMPLETE THE LOOP✦24 V MOTION✦USB 3 SLIP RING✦ORBI ETHERNET✦UBUNTU + CAN✦CEREBROVISIONPRO✦MAKE • TEST • LEARN✦

Animated knowledge deck

See the invisible parts of a circuit.

Charge moves slowly, but electric and magnetic fields carry changes through a circuit quickly. Switch views to watch DC drift, AC oscillation, stored fields, and resonance before you build them.

ROB FIELD VIEWDC · ONE DIRECTION

A battery maintains one polarity. Electrons drift around the external metal loop from negative toward positive while conventional current points the other way.

Your maker journey

Eighty builds. From one bulb to all of ROB.

Each mission adds one new idea. Finish a build to unlock the next bench—just like a real engineer earning access to new tools.

⚡

Preparing your circuit bench…

WIRE TOOLSelect a terminal to start a wire

EXTERNAL ELECTRON DRIFT − → around the complete loop → + Battery chemistry keeps the charges separated.

SUPPLY0.0 Vvoltage

FLOW0.0 mAcurrent

LOAD— Ωresistance or impedance

DC ENERGY SCOPE

0 V DC · OPEN LOOP

Builds 9–16 · Waves, fields, and frequency

DC holds direction. AC keeps changing.

Voltage is an energy difference created by an electric field. Current is charge moving in response. Any current creates a magnetic field; any changing magnetic field can create an electric field. That field partnership is the heart of generators, motors, transformers, radios, and RLC circuits.

Direct current

A battery or solar cell maintains a steady polarity. After a circuit settles, voltage and current stay in one direction. The scope shows a flat level above zero.

Battery · solar · Arduino HIGH

Alternating current

Polarity and current direction reverse repeatedly. A sine wave crosses zero twice per cycle. Frequency in hertz tells how many full cycles happen each second.

Generator · audio · radio signals

RMS

Useful AC magnitude

Because AC is always changing, engineers often use RMS values. A stated 5 V RMS sine wave has the same heating effect in a resistor as 5 V DC.

Vrms = Vpeak ÷ √2 for a sine

Impedance

In AC, total opposition is called impedance. It combines resistance with capacitive and inductive reactance and is measured in ohms.

Z controls RMS current

Capacitor field

Opposite charge gathers on plates separated by an insulator. Energy is stored in the electric field; electrons do not cross the dielectric.

Xc = 1 ÷ (2πfC)

Inductor field

Current through a coil builds a magnetic field. The coil opposes sudden current changes by producing a counter-voltage.

XL = 2πfL

RLC

Resonance

At f₀, capacitive and inductive reactance are equal. Energy trades between the capacitor’s electric field and the inductor’s magnetic field.

f₀ = 1 ÷ (2π√LC)

The engineer’s superpower

Ohm’s law makes circuits predictable.

Voltage is the push, current is the flow, and resistance is what slows the flow. Know any two and V = I × R reveals the third.

VoltageThe electrical push

volts

CurrentCharge flowing each second

amps

ResistanceOpposition to flow

ohms

V = I × ROHM-O-MATIC 3000

Enter two values. Leave the mystery value blank.

VVoltagevolts ICurrentmilliamps RResistanceohms

Tip: current is entered in milliamps here, so 0.02 A becomes 20 mA.

Builds 7, 8, 17–20 & 26–45 · Tiny computer, full robot

From electricity to instructions.

An Arduino Uno is a small computer that reads inputs and controls outputs. Start with a compiler-checked blink sketch, then learn pull-up buttons, PWM, encoders, independent treads, bounded serial messages, telemetry, and the local watchdog that stops motion when a computer goes quiet.

1
setup()Runs once. Configure pin modes and startup behavior.
2
loop()Repeats while the board has power.
3
digitalRead()Turns a button or logic voltage into HIGH or LOW.
4
analogRead()Quantizes 0–5 V into one of 1,024 ADC codes.
5
analogWrite()Creates PWM on supported ~ pins; it is not a true DAC.
6
map()Rescales a sensor range into a useful output range.

Builds 21–25 · Engineer refresher bench

Timing, gain, feedback, and thresholds.

These classic building blocks remain useful whether you are meeting them for the first time or reviewing a design before the Maker Faire opens. The ideal equations start the conversation; real-device limits finish it.

555

Astable oscillator

The capacitor charges through R1 + R2 and discharges through R2. No stable state means the output keeps switching.

f ≈ 1.44 ÷ ((R1 + 2R2)C)

1×

Monostable pulse

An active-low trigger starts one timed HIGH pulse. Threshold ends it when the capacitor reaches about two-thirds VCC.

t ≈ 1.1RC

△

Ideal op-amp rules

With stable negative feedback, input current is nearly zero and V+ is driven close to V−. Those rules fail when limits are exceeded.

I+ ≈ I− ≈ 0 · V+ ≈ V−

BUF

Voltage follower

Unity feedback gives gain 1, high input impedance, and low output impedance—useful for isolating a sensor from its load.

Vout ≈ Vin

GAIN

Non-inverting amplifier

Two resistors set closed-loop gain. The supply rails, common-mode range, gain-bandwidth product, and slew rate still set boundaries.

Av = 1 + Rf ÷ Rg

CMP

Comparator behavior

Without negative feedback, a tiny difference drives the output high or low. Positive feedback adds hysteresis to reject threshold noise.

V+ > V− → HIGH

Builds 26–50 · ROB systems campaign

Power. Protocol. Presence.

The middle campaign follows a command from two thumb controls to physical tread energy, measured feedback, an authenticated Cerebro session, live cameras, and bounded arm motion.

26–38

Build the base

Separate logic and motor power, drive and reverse a tread with an H-bridge, mix two sides, stop hard, read quadrature encoders, close a speed loop, and measure the battery.

12 V energy · 5 V logic · PWM · feedback

39–45

Teach the computer

Open a passive USB serial link at 250,000 baud, identify the base, reject malformed or damaged frames, enforce freshness, return telemetry, and run ROB’s 5 Hz base snapshot.

intent → frame → validate → actuate → measure

46–50

Pilot through Cerebro

Authenticate a live operator, acquire expiring authority, keep video separate from STOP, initialize a measured seven-joint arm, and complete a CerebroVisionPro remote session.

identity · authority · dead-man · safe state

01CerebroVisionProoperator intent + dead-man

⇄control

02Cerebro computeridentity, authority, bounds

⇄USB + telemetry

03Arduino base5 Hz snapshots + watchdog

→local energy

04Treads · arms · camerasmeasured motion + separate video

Builds 51–80 · ROB field-systems campaign

Build the robot behind the robot.

Now the bench expands into ROB’s installed architecture. Follow energy from the source to each return, preserve USB and Ethernet signal paths across rotation, commission every rail independently, and make local safe states stronger than any network promise.

51–57

Motion power across rotation

Regulate and fuse the 24 V rail, feed both tread drivers, current-limit the torso stepper, home before motion, and route the complete 14 AWG power loop through the hybrid slip ring.

12 V in → 24 V regulated → branch protection → load → 0 V return

58–64

USB sensing and robot Ethernet

Enumerate RPLIDAR through the USB 3-capable rotating channel, detect stale scans and link faults, then build an Orbi-centered Ethernet star for Cerebro, Amber Ubuntu, and the Insta360 Pro II.

rotating sensor → slip ring → USB host · endpoints → Orbi LAN

65–70

12 V belly compute power

Create a protected 12 V rail, feed a correctly rated inverter, keep the AC side sealed, power the Mac mini plus approved Orbi and camera adapters, and test startup surge, voltage sag, and thermal margin.

DC classroom wiring · sealed AC boundary · measured nameplates

71–77

48 V arms, CAN, and Ubuntu

Commission the 48 V arm rail without a live arm, split power after a normally open contactor, terminate CAN correctly, attach USB-to-CAN to the Amber Linux box, and bridge bounded Cerebro targets to measured arm feedback.

48 V energy ≠ CAN data ≠ Ethernet authority

78–80

Commission, remember, graduate

Bring every domain online in a measured sequence, prove local watchdog behavior during compute loss, sync an optional private CloudKit learner passport, and unlock a minimal QR reward claim for ROB’s Maker Faire booth.

inspect → energize → measure → fault → recover → explain

ENERGY12 V SOURCE24 V motion · 12 V compute · 48 V arms

→

ROTATIONHYBRID SLIP RING14 AWG power pair · USB channel

→

COMPUTEMAC MINI + UBUNTUCerebro orchestration · Amber CAN gateway

⇄

NETWORKORBI BACKPACKCerebroVisionPro · Insta360 · robot LAN

Builds 81–90 · ROB learning-book bridge

Help ROB recover, listen, and put on a show.

These encore builds join lessons scattered across all eight Building R.O.B. volumes and the complete field manual. They turn component facts into complete robot behaviors while keeping motor authority local, bounded, and easy to stop.

81–84

Base lift & recovery

Add the tread base’s independent flipper motor, give PWM, direction, and brake their own channel, home it, catch a jam, and use tilt plus current evidence to lift without tipping.

support polygon · center of mass · feedback · abort

85–87

Speakers & ROB techno

Follow energy from digital samples through an audio interface, magnetic voice coil, moving cone, and air. Then mix ROB Training’s original procedural kick, bass, hats, and melody through a limiter.

samples → signal → magnetic force → sound

88–90

Far-field voice & show control

Compare close and distant speech, measure signal-to-noise ratio, remove speaker echo, ask for clarification when confidence is low, and cancel music plus motion with one simulated STOP.

visible mic notice · transcript confidence · authority

CONFERENCE MIC→CEREBRO VALIDATION→BASE FLIPPERandROB SPEAKERS

Your robot takes shape

Assemble it. Color it. Take it training.

Starting with ROB’s build tutorials, each finished chapter snaps a completed system onto your personal droid. Choose protective housing, create a portable Droid Code, and use the same visual identity in ROB Training on the web, iPhone, iPad, or Apple Vision Pro.

••‿

YOUR CIRCUIT QUEST DROID

Droid designation Housing color Housing material Panel style

VIRTUAL TOOL MOUNTSide pan-tilt Gatling

A yaw servo scans left and right, a tilt servo aims up and down, a red game dot confirms lock, and a blue game beam pops simulated balloons and tags training targets.

RED TARGETBLUE TRAINING BEAM

Portable Droid Code

Train this droid ↗

Droid profile ready.

01LEARN

Wire Circuit Quest builds. Chapter completion assembles a tested robot section.

→

02CUSTOMIZE

Choose color, material, panel style, and a kid-safe virtual training loadout.

→

03PLAY TOGETHER

Import the checked code. Nearby battles exchange the profile so every pilot sees the same droid.

Optional learner passport

Remember the maker. Reward the journey.

The 80 core completed builds are saved to this browser. Apple sign-in can merge that progress into your private CloudKit database so it can be recalled elsewhere. Book Bridge builds remain local droid mastery. No email, camera data, location, microphone audio, or robot telemetry is stored by this lab.

01 THIS DEVICE ROB-LOCAL-ONLY

This random first-party device code is not an advertising identifier and never leaves the browser unless you choose account sync.

Your nickname is private progress data.

02 CURRICULUM PROGRESS 0 / 80

Local and private CloudKit mission lists are merged by union: completing a build on either browser never erases a build completed on the other.

Preparing the device passport…

03 MAKER FAIRE REWARD ROB SCHOOL GRADUATE

Complete all 80 builds to unlock one stable account-bound pass.

Maker Faire field guide

Make boldly. Test safely. Explain what happened.

This game is a safe place to experiment—even a virtual short only makes ROB shout “stop!” Real circuits deserve slower hands and a mentor.

Build unpowered

Switch off or disconnect the source before moving real wires. Have a mentor check the circuit first.

Stay low voltage

Use protected classroom kits and approved batteries. AC lessons here are virtual—never experiment with wall outlets, mains wires, or ROB’s installed power systems.

Protect the parts

LEDs need current-limiting resistors. Rechargeable batteries need the correct charger and protection circuit—never wire a panel straight to a cell.

Stop and observe

Disconnect power if anything becomes hot, swollen, damaged, noisy, or smelly. Evidence is useful; smoke is not a goal.

For families & educators Ask learners to make a prediction before every test: “Where will charge flow?”, “What voltage should the meter show?”, and “What changes after sunset?”

Observe
Predict
Build
Measure
Explain
Revise

Pocket notebook

Words every circuit maker knows

Closed circuit: An unbroken path from a source, through a load, and back to the source.
Voltage drop: Energy transferred across a component. In a series loop, all drops add up to the source voltage.
Series: Components share one path and the same current.
Parallel: Components have separate branches with the same voltage across each branch.
Ground (GND): The circuit’s shared reference and return path—not a magic place where electricity disappears.
Charge controller: Electronics that safely manage energy between a solar panel, rechargeable battery, and load.
Electron flow: In the external metal wires, electrons drift from a source’s negative terminal through the complete loop toward its positive terminal. Conventional current arrows point the opposite way.
Alternating current (AC): Voltage polarity and current direction reverse periodically. Electrons oscillate locally instead of traveling from a fixed negative terminal to a fixed positive terminal.
RMS: A practical measure of an AC waveform’s effective voltage or current. For a sine wave, RMS is peak value divided by √2.
Capacitance: The ability to store energy in an electric field between separated conductors. It is measured in farads.
Inductance: The ability to store energy in a magnetic field and oppose changes in current. It is measured in henries.
Reactance: Frequency-dependent opposition from capacitance or inductance. Capacitive reactance falls with frequency; inductive reactance rises.
Impedance: The total AC opposition made from resistance and reactance. Like resistance, it is measured in ohms.
Resonance: The frequency where inductive and capacitive reactance balance, allowing strong energy exchange between electric and magnetic fields.
ADC: An analog-to-digital converter maps a voltage range into numbered steps. More bits provide more possible codes, not automatically more accuracy.
PWM: Pulse-width modulation changes average delivered energy by changing how long a digital output stays on during each fast cycle.
555 timer: A classic timing IC with trigger and threshold comparators, an internal divider, latch, discharge transistor, and output driver.
Operational amplifier: A high-gain differential amplifier normally used with feedback to create predictable buffers, gains, filters, and control circuits.
Negative feedback: Returning part of an output to oppose the input error. It trades open-loop gain for stable, predictable closed-loop behavior.
Saturation: The condition where an amplifier’s requested output exceeds what its supply rails and output stage can provide, causing clipping.
Comparator: A circuit that reports which of two input voltages is greater by driving its output toward a high or low state.
H-bridge: A power-driver arrangement that can apply either polarity across a DC motor so logic signals can command forward, reverse, coast, or brake.
Quadrature encoder: Two phase-shifted pulse channels that let a controller count rotation and determine direction.
Differential drive: A steering method that controls left and right treads independently. Their average sets translation; their difference sets turning.
Serial frame: One complete, delimited message with defined fields. Sequence, bounds, and integrity checks help a receiver reject partial or stale meaning.
Telemetry: Measured state returned by a system—such as encoder speed, battery voltage, mode, command acknowledgement, freshness, and faults.
Watchdog: A local deadline that forces a known safe output when fresh valid commands stop arriving.
Authority lease: Permission to control a subsystem for a short time. It expires, releases, or is revoked independently of network connectivity.
Dead-man control: An input that must remain actively held and fresh for motion to continue. Release or stale input commands the safe state.
Control plane: The timely path for commands, acknowledgements, authority, and stop state. It must not wait behind optional media.
Media plane: The separate path for camera video and recovery. Frames may drop without delaying safety-critical control.
Buck-boost converter: A regulated DC converter that can raise or lower voltage within its current, thermal, efficiency, and protection limits.
Wire gauge: A conductor-size system. Gauge is only one part of a current rating; insulation, temperature, bundling, connectors, and duty cycle matter too.
Slip ring: An assembly that transfers rated power or signals across a rotating joint. High-speed data requires a purpose-designed channel, not ordinary power contacts.
Stepper motor: A multi-phase motor moved in discrete electrical steps. A driver regulates winding current; homing establishes an absolute mechanical reference.
RPLIDAR: A rotating range sensor that returns angle-and-distance samples. A consumer must reject stale, incomplete, or mis-timestamped scans.
Ethernet star: A topology where each endpoint has its own link to a switch or router, making paths and failures easier to isolate.
Inverter: A device that converts DC into AC. In this lab its AC output is always a sealed, listed-equipment boundary and never a learner wiring area.
CAN bus: A differential multi-node network using CAN-H and CAN-L, a defined reference strategy, short stubs, and termination at the two physical ends.
CloudKit passport: Optional private account storage that merges completed mission numbers with the progress saved on this browser.
Reward claim: A minimal public completion record referenced by a QR code. It is separate from the private learner nickname and progress record.