High School / HS-10
Available Grades 9–12 Energy Robotics & controls
Build a two-axis light-seeking tracker, sweep a small solar panel's I–V curve to find its maximum power point, and compare fixed versus tracked energy.
Students build a two-axis, light-seeking tracker for a small 6 V solar panel, then measure what the panel can really deliver: they sweep its I–V curve with a PWM-switched resistor, find the maximum power point (MPP), run a perturb-and-observe MPPT algorithm, and log tracked versus fixed energy over an afternoon against a clear-sky model built from NOAA's solar-position equations.
Low voltage only, no mains. The panels are ≤ 8.8 V open-circuit (Voltaic P126 datasheet, all revisions); the servos run from a 5 V Always-On USB power bank and the controller from the laptop's USB port. Never look at the Sun: the tracker is aimed by its own sensor and by its shadow.
Students will:
Every high school pack includes worked math and physics, prediction-versus-measurement labs, at least two design-and-test iterations, data logging, a rubric, and documentation templates, plus printable Builder's Corner build journal pages.
Parts, specs, quantities, and estimated unit costs, with places to buy. Prices change; anything marked as an estimate is an estimate. Links were checked when the BOM was written.
Totals are computed from the line items below. Prices were read from vendor pages on the dates shown and will change. Rows tagged estimate have no verified link and are planning numbers only.
| ID | Part & spec | Qty | Unit (typical) | Line (typical) | Where to buy | Cheaper substitute | Adult handling / safety gear |
|---|---|---|---|---|---|---|---|
| E1 | Solar panel 6 V 2 W, ETFE (Voltaic P126) Adafruit PID 5366 · 112 × 136 × 2.7 mm, 79 g; Voc 8.74 V, Vmp 7.48 V, Imp 0.35 A, Isc 0.37 A, Pmax 2.62 W ±10 % (Voltaic datasheet R3C, Aug 2026; Adafruit page shows older R1E: 8.51 V/7.28 V/0.33 A/2.37 W); read the revision on the panel label; 12 monocrystalline cells; 3.5 × 1.1 mm DC jack (vendor). One tracked, one fixed | 2 | $20.95 | $41.90 | adafruit.com Adafruit $20.95 · checked 2026-10-09 · In stock | Same panel direct from Voltaic Systems (P126, $21.00, voltaicsystems.com/P126, seen in search 2026-10-09, not fetched). Low total: one panel only (Lab 5 then alternates tracked/fixed days) | Panels get hot in sun; handle by the edges |
| E2 | 3.5/1.1 mm to 5.5/2.1 mm DC adapter cable Adafruit PID 2788 · panel plug to standard barrel | 2 | $1.50 | $3.00 | adafruit.com Adafruit $1.50 · checked 2026-10-09 · Page markup shows out of stock: re-check | Cut the panel lead and use screw terminals (voids the plug) | — |
| E3 | 2.1 mm DC jack to screw terminal Adafruit PID 368 · two for the panels, one for servo power | 3 | $2.00 | $6.00 | adafruit.com Adafruit $2.00 · checked 2026-10-09 · In stock | — | — |
| E4 | ESP32 Feather V2 (controller) Adafruit PID 5400 · USB-C | 1 | $19.95 | $19.95 | adafruit.com Adafruit $19.95 · checked 2026-10-09 · In stock | Adafruit HUZZAH32 Feather (PID 3405); check the ADC pins | Header soldering: adult supervision, eye protection, ventilation |
| E5 | 8-Channel PWM/Servo FeatherWing (PCA9685) Adafruit PID 2928 · I2C 0x40 | 1 | $9.95 | $9.95 | adafruit.com Adafruit $9.95 · checked 2026-10-09 · In stock | Generic PCA9685 breakout | — |
| E6 | Stacking headers for Feather Adafruit PID 2830 | 1 | $1.25 | $1.25 | adafruit.com Adafruit $1.25 · checked 2026-10-09 · In stock | Plain female headers | — |
| E7 | INA219 high-side current/voltage sensor Adafruit PID 904 · 26 V / ±3.2 A max, 0.1 Ω shunt, STEMMA QT; set addresses 0x41 (A0) and 0x44 (A1) | 2 | $9.95 | $19.90 | adafruit.com Adafruit $9.95 · checked 2026-10-09 · In stock | Multimeter readings by hand for Lab 2 (no logging) | — |
| E8 | N-channel logic-level MOSFET 60 V 30 A (FQP30N06L) SparkFun · TO-220; PWM-switched load (R_eff = R/duty); R_DS(on) ≤ 0.045 Ω at V_GS = 5 V (datasheet): gate driven to 5 V by E8a | 2 | $1.25 | $2.50 | sparkfun.com SparkFun $1.25 · checked 2026-10-09 · In stock (page shows both in/out-of-stock markup; re-check) | Any N-MOSFET with R_DS(on) specified at the gate voltage you drive (5 V with the buffer; ≤ 2.5–3.0 V without) | — |
| E8a | 74AHCT125 quad buffer, DIP-14 (MOSFET gate drive 3.3 V -> 5 V) Texas Instruments SN74AHCT125N · VCC 4.5–5.5 V from the Feather USB pin, V_IH(min) 2.0 V (TI datasheet); two channels drive the two FQP30N06L gates | 1 | $0.87 | $0.87 | tme.com TME $0.87 (1 pc) · checked 2026-10-09 · 1552 in TME stock | US stock: DigiKey 296-4655-5-ND (TI SN74AHCT125N), $1.00 (1 pc), 3,471 in stock 2026-10-09 (digikey.com/en/products/detail/texas-instruments/SN74AHCT125N/375798). TME ships from Poland: check shipping. Adafruit PID 1787 was out of stock 2026-10-09 | — |
| E9 | Power resistor kit 10 W (1, 2, 4, 8, 16 Ω × 5) SparkFun KIT-13053 · 4 Ω is the PWM load (one per panel); the rest build fixed loads for Lab 2 | 1 | $9.50 | $9.50 | sparkfun.com SparkFun $9.50 · checked 2026-10-09 · In stock (page shows both in/out-of-stock markup; re-check) | Two 4–5 Ω, ≥ 5 W resistors | Resistors get hot (can exceed 100 °C in sun at ~2.6 W, ESTIMATE): mount on standoffs, do not touch while running |
| E10 | Electrolytic capacitor 1000 µF 25 V SparkFun COM-08982 · two per panel across the load node (smooths the PWM) | 4 | $0.50 | $2.00 | sparkfun.com SparkFun $0.50 · checked 2026-10-09 · In stock | Any ≥ 16 V electrolytic, 1000–2200 µF | Observe polarity (stripe = negative) |
| E11 | Photocell (CdS photoresistor) Adafruit PID 161 · quadrant tracking sensor | 4 | $0.95 | $3.80 | adafruit.com Adafruit $0.95 · checked 2026-10-09 · In stock | Four matched photodiodes / phototransistors (change the divider) | CdS contains cadmium: don't cut or burn; dispose as e-waste |
| E12 | 1.0 kΩ resistors (pack of 25) Adafruit PID 4294 · photocell dividers | 1 | $0.75 | $0.75 | adafruit.com Adafruit $0.75 · checked 2026-10-09 · Page markup shows out of stock: re-check | Classroom stock | — |
| E13 | 100 Ω and 10 kΩ resistors (gate resistor + pull-down, 2 each) Classroom stock | 1 | $1.00 estimate | $1.00 | Electronics supplier (no link) — | — | — |
| E14 | Standard servo FEETECH FS5106B (pan + tilt) Pololu 3425 · FEETECH spec A/0: 40.15 × 20.15 × 37.2 mm, 41.5 g; 4.8 kg·cm @ 4.8 V; idle 6 mA, running 140 mA, stall 1.8 A at 4.8 V; horns included | 2 | $22.58 | $45.16 | pololu.com Pololu $22.58 each · checked 2026-10-09 · Not recorded | Any standard-size servo (re-measure; window is 20.5 × 41.2 mm) | Pinch points at the yoke and frame |
| E15 | USB to 2.1 mm barrel cable Adafruit PID 2697 · power bank Always-On USB-A port → servo-power jack (5 V) | 1 | $2.75 | $2.75 | adafruit.com Adafruit $2.75 · checked 2026-10-09 · In stock | — | — |
| E16 | USB power bank with Always-On USB-A output (no low-current cutoff), 5 V ≥ 2 A Voltaic Systems V25 · 6,700 mAh; USB-A ports "will not shut off even if your device is drawing low or no power" (Voltaic V25 page). Charge it from the side USB-C, not the top PD port, which disables Always-On. Servo power outdoors (no mains) | 1 | $45.00 | $45.00 | voltaicsystems.com Voltaic Systems $45.00 · checked 2026-10-09 · In stock | Voltaic V50, or any bank documented as "always on" / "low-current mode"; test it: servos idle 10 min, then goto 60 90 must still move. Low total assumes the school already owns such a bank | Keep lithium packs in the shade; never leave one in a hot car or in direct sun |
| E17 | USB-A to USB-C data cable Adafruit PID 4474 | 1 | $4.95 | $4.95 | adafruit.com Adafruit $4.95 · checked 2026-10-09 · In stock | Classroom cable | — |
| E18 | Hook-up wire 22 AWG solid (6 × 25 ft) Adafruit PID 1311 | 1 | $15.95 | $15.95 | adafruit.com Adafruit $15.95 · checked 2026-10-09 · In stock | Classroom stock | — |
| E19 | Small perfboard or solderless breadboard (load board) INA219s, MOSFETs, capacitors, resistor terminals | 1 | $5.00 estimate | $5.00 | Electronics supplier (no link) — | — | — |
| Subtotal | $241.18 | Low-cost path: $174.28 | |||||
| ID | Part & spec | Qty | Unit (typical) | Line (typical) | Where to buy | Cheaper substitute | Adult handling / safety gear |
|---|---|---|---|---|---|---|---|
| S1 | Baltic birch plywood 3 mm, 12 × 20 in Wood Vault, 1/8" Laser/CNC grade variant; 3 sheets | 3 | $3.50 | $10.50 | woodvault.com The Wood Vault $3.50 per sheet (1/8" Laser/CNC grade variant) · checked 2026-10-09 · Not confirmed (variant availability not in page HTML) | Any 3 mm laser plywood (slots are 3.2 mm) | — |
| S2 | M3 screws/nuts/washers, M2 screws, zip ties, rubber feet Tilt pivot, fixed-stand hinge and prop, servo ears, panel ties | 1 | $6.00 estimate | $6.00 | Hardware store (no link) — | Classroom stock | — |
| S3 | Wood glue, matte black paint marker (vanes), sandbag or clamps Vanes black so they cast clean shadows; weigh the base down outdoors | 1 | $6.00 estimate | $6.00 | Hardware store (no link) — | — | — |
| S4 | Laser cutter access or cutting service 3 sheets (estimate) | 1 | $15.00 estimate | $15.00 | Makerspace / cut service (no link) — | — | Trained adult operator; never leave a running laser |
| Subtotal | $37.50 | Low-cost path: $25.50 | |||||
| ID | Part & spec | Qty | Unit (typical) | Line (typical) | Where to buy | Cheaper substitute | Adult handling / safety gear |
|---|---|---|---|---|---|---|---|
| T1 | Temperature-controlled soldering iron Pinecil | 1 | $68.50 | $68.50 | sparkfun.com SparkFun $68.50 · checked 2026-10-09 · Not recorded | Assumed owned in the low total | Adult supervision |
| T2 | Lead-free solder 15 g SparkFun | 1 | $4.95 | $4.95 | sparkfun.com SparkFun $4.95 (single-unit price) · checked 2026-10-09 · Not recorded | — | Wash hands after soldering |
| T3 | Safety glasses, ANSI Z87.1 (Z87+) impact-rated, clear 3M SecureFit SF201AF · clear anti-fog polycarbonate lens marked Z87+ (ANSI Z87.1 impact-rated; 3M spec table on strobelssupply.com and safetycompany.com, read 2026-10-09); for soldering, cutting, servo testing (NOT for viewing the Sun) | 2 | $5.32 | $10.64 | platt.com Platt Electric Supply $5.32 EA · checked 2026-10-09 · 40 in stock (company-wide) | Any glasses marked Z87+ (ANSI Z87.1 high-impact). Not SparkFun SWG-11046: it lists only CE/EN 1836, a sunglass standard, not impact-rated | Check the Z87+ marking on the frame on arrival |
| T4 | Digital multimeter SparkFun basic DMM · Voc/Isc spot checks, polarity | 1 | $21.50 | $21.50 | sparkfun.com SparkFun $21.50 · checked 2026-10-09 · Not recorded | Assumed owned in the low total | — |
| T5 | Laptop with Python 3, numpy, matplotlib, pyserial, Arduino IDE Logs over USB outdoors (battery powered) | 1 | $0.00 estimate | $0.00 | School (no link) — | — | — |
| Subtotal | $105.59 | Low-cost path: $15.59 | |||||
The pack is digital files only. Hardware is bought separately.
These are standards the pack's activities are mapped to by Laue Labs. They are not a certification or endorsement by any standards body or state.
| Activity | NGSS | Common Core Math |
|---|---|---|
| Lab 1 Sensor and servos | HS-ETS1-2 (break a problem into smaller ones: sensing, actuation, control); HS-PS4-5 (devices using light to capture information) | HSG-SRT.C.8 (trig: shadow length h tan θ) |
| Lab 2 I–V curve | HS-PS3-3 (design a device that converts energy); HS-PS3-1 (energy flow model) | HSF-IF.B.4 (interpret key features: maximum of P(V)); HSA-CED.A.4 |
| Lab 3 Angle and shading | HS-PS4-3 (light as particles/photons: current ∝ light); HS-ESS1-4 by extension (Sun's apparent motion) | HSF-TF.A/B (cosine model); HSF-LE.A.4 (logarithms) |
| Lab 4 MPPT | HS-ETS1-3 (trade-offs: step size vs speed); SEP 5 (computational thinking) | HSF-BF.A.1 (model a relationship) |
| Lab 5 Tracked vs fixed | HS-ESS3-2 / HS-ETS1-3 (evaluate energy solutions, cost-benefit); HS-ESS3-4 by extension | HSN-Q.A.1 (units Wh, W·s); HSS-ID.B.6 (compare model and data) |
One student or one household.
You may:
You may not:
One homeschool family, or one co-op group of up to 10 learners with its facilitator(s).
You may:
You may not:
One teacher with up to 30 students in a single class or cohort.
You may:
You may not:
All licenses: digital files only (hardware not included). Keep Laue Labs attribution on printed handouts. After checkout you get an instant download on the thanks page. License questions, more learners, or site licenses: lance.haney@gmail.com.
