Open Hardware Spectrometer
Build a Portable 18-Band Spectrometer with AS7265x and Raspberry Pi Pico — Capture Absorption Curves in Python
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Transform a Raspberry Pi Pico into a field-ready spectrophotometer that resolves 18 discrete wavelengths from violet (410 nm) through near-infrared (940 nm). The AS7265x sensor sits inside a precision optical tube enclosure, rejecting stray light so you can measure absorbance of dyes, leaf chlorophyll, water samples, or chemical solutions. The Pico writes time-stamped spectral data to microSD, and the included Python script generates absorbance curves as soon as you connect to a computer — no proprietary software needed.
What You'll Build
A battery-powered spectral acquisition instrument with an OLED live readout. You’ll assemble the optical tube, solder the sensor breakout, wire the RTC and storage, and flash the firmware. The result is a handheld spectrometer that captures an 18‑band spectrum onto a microSD card and exports a CSV ready for absorbance, transmittance, or reflectance plotting in Python. It’s a fully self-contained tool for lab or field use.
What You'll Learn
- Interface the AS7265x 18‑channel spectral sensor and extract calibrated count data over I²C
- Design a tube‑based optical path that minimises ambient light and maximises measurement repeatability
- Implement microsecond‑accurate timestamps with DS3231 RTC and log readings to microSD from a Pico
- Program absorbance calculation and curve plotting in Python to analyse concentration and spectral shape
Kit Contents
| Component | Quantity |
|---|---|
| Raspberry Pi Pico | 1 |
| AS7265x Spectral | 1 |
| DS3231 RTC | 1 |
| MicroSD Module | 1 |
| 0.96in OLED | 1 |
| 3.7V LiPo 1000mAh | 1 |
| TP4056 Module | 1 |
| 4.7kΩ Resistors | 5 |
| PCB Prototype Board | 3 |
| Optical Tube Enclosure | 1 |
| Soldering Iron | 1 |
| Solder Wire | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
Built for advanced college students and early researchers — think B.Tech ECE/EEE final‑year projects at IITs, NITs, or VIT, Smart India Hackathon teams prototyping rapid material analysers, and M.Sc. Physics or Chemistry labs needing inexpensive spectrophotometers. It also fits ATL Tinkering Lab mentors guiding students beyond basic sensors into real spectroscopic analysis.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project — accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
Scan the QR code to talk to the AI companion, trained on this spectrometer project. If you need human help, WhatsApp or email our team for specific guidance.
Can I measure absorbance of liquids with this kit?
Yes, the optical tube includes a slot for standard cuvettes. The Python script calculates absorbance from a stored reference, so you can quantify concentration of dyes, chlorophyll extracts, or chemical solutions.
Does this kit require a soldering station?
A basic soldering iron and lead‑free solder are included. All connections are through‑hole, so a simple desk setup is sufficient — no hot‑air rework needed.
How accurate are the readings compared to a lab spectrophotometer?
The AS7265x sensor outputs factory‑calibrated 18‑band data with NIST‑traceable accuracy. It delivers ±5% repeatability for most visible‑range measurements, perfectly adequate for teaching and field research where a $5000 instrument isn’t an option.
AS7265x 18-band spectral sensor in optical tube. Pico logs spectrum. Python software plots absorption curves.
What's in this kit
Choose your assembly option:
- Soldering Kit — 25W soldering iron, 60/40 solder wire, flux, and small perfboard for permanent assembly.
- Breadboard Combo — 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items