Set up a bench
From zero dollars to a real instrument, in tiers. Buy the smallest one that lets you start this week.
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A bench is not a room. It is a shoebox of parts, a laptop, and a corner of a desk. Here are four tiers. The first costs nothing and gets you through Phase 1’s zero-dollar project. The second is about $190 and covers every project in Phase 1. The third adds the real instrument. The fourth is borrowed.
Tier 0: the laptop you already have
Python 3, the MNE-PythonMNE-Python The standard open-source Python library for EEG and MEG analysis: filtering, epoching, ICA, topographies, source localization. Related: Independent component analysis (ICA)Independent component analysis (ICA) A method that unmixes multichannel data into statistically independent sources, so blinks and heartbeat can be identified and removed. . Glossary entry library, and real EEGElectroencephalography (EEG) Recording the brain's electrical activity from electrodes on the scalp, a few tens of microvolts of blurred, summed cortical activity. Related: Electrocorticography (ECoG)Electrocorticography (ECoG) Recording from electrodes placed on the surface of the brain under the skull, usually during epilepsy surgery evaluation; cleaner and sharper than EEG. , Magnetoencephalography (MEG)Magnetoencephalography (MEG) Recording the tiny magnetic fields produced by cortical currents with superconducting sensors in a shielded room; less blurred by the skull than EEG, and far more expensive. , Volume conductionVolume conduction The spreading of currents from a source through the conductive tissues of the head, which is why one source shows up on many electrodes and why scalp EEG is blurry. , Microvolt (µV)Microvolt (µV) One millionth of a volt. Scalp EEG is tens of microvolts; a AA battery is 1.5 million of them. . Glossary entry downloaded from PhysioNetPhysioNet A free archive of physiological recordings including EEG, ECG, and sleep data, run out of MIT. Related: Sleep-EDFSleep-EDF A public PhysioNet dataset of whole-night sleep recordings with expert stage labels, the standard training set for automatic sleep staging. . Glossary entry. Every simulator on this site. Every explainer. If you have no money this month, start here; nothing you learn is wasted, and you will know exactly which parts you want when you can buy them.
Install Python from the official installer or Miniforge. Then:
pip install mne numpy scipy matplotlibTier 1: the starter bench
Everything for the SpikerBoxSpikerBox Backyard Brains' small battery amplifier that lets you hear action potentials from a cockroach leg on a speaker; easy to build yourself. Related: Action potentialAction potential The brief, all-or-nothing voltage spike a neuron fires, about a millisecond long and about 100 millivolts tall across its membrane. , Instrumentation amplifierInstrumentation amplifier A precision differential amplifier with very high input impedance and high CMRR, built from three op-amps and sold as a single chip such as the INA128 or AD8232. . Glossary entry, one channel of EEGElectroencephalography (EEG) Recording the brain's electrical activity from electrodes on the scalp, a few tens of microvolts of blurred, summed cortical activity. Related: Electrocorticography (ECoG)Electrocorticography (ECoG) Recording from electrodes placed on the surface of the brain under the skull, usually during epilepsy surgery evaluation; cleaner and sharper than EEG. , Magnetoencephalography (MEG)Magnetoencephalography (MEG) Recording the tiny magnetic fields produced by cortical currents with superconducting sensors in a shielded room; less blurred by the skull than EEG, and far more expensive. , Volume conductionVolume conduction The spreading of currents from a source through the conductive tissues of the head, which is why one source shows up on many electrodes and why scalp EEG is blurry. , Microvolt (µV)Microvolt (µV) One millionth of a volt. Scalp EEG is tens of microvolts; a AA battery is 1.5 million of them. . Glossary entry, muscle-to-motion, and the eye joystick. The multimeter and the soldering iron will outlast your degree.
Tier 1
| Part | Where | Qty | Approx. |
|---|---|---|---|
| A laptop you already own, with Python 3 Windows, macOS, or Linux. Install Python via the official installer or Miniforge; MNE-Python and NumPy via pip. | Your bag | 1 | free |
| 9 V batteries, ×4, and snap connectors $9.69 for four Energizer cells plus $3.59 for three snap connectors (Amazon B0CR8RKQ5Q). Two batteries give you a ±9 V split supply. Never power anything touching skin from the wall or from a laptop USB port. | Amazon, any store | 1 | $13 |
| AD8232 heart-rate monitor breakout A complete biopotential front end on a board, and the clone comes with a cable and pads. SparkFun's version is $24.41 and has better documentation and a known-good layout. Use it to compare against your own amplifier, and to see what a good DRL looks like. | Amazon, SparkFun | 1 | $11 |
| Alligator clip leads, ×10 | Amazon | 1 | $5 |
| Arduino Nano clone (ATmega328P, CH340), ×3 A three-pack is cheaper than one genuine board and you will kill one. The official Nano Every is $14.90 for a single board if you want Arduino's support. Either has the 10-bit analog input the Web Serial plotter needs; CH340 boards work with Chrome's Web Serial. | Amazon | 1 | $13 |
| Auto-ranging digital multimeter You will use this more than any other tool, so buy an auto-ranging one; the $17 TM-510 is auto-ranging. Below that price you get manual ranging, which wastes time. A true-RMS meter is about $35 and you will not need it this year. | Amazon | 1 | $17 |
| Disposable snap ECG electrodes, bag of 50 3M Red Dot, $11.40 for fifty. Clip the alligator leads onto the snap studs rather than buying leads; a set of four 3.5 mm snap leads is $9.99 if you want them tidy. | Amazon | 1 | $12 |
| EEG conductive paste, 50 g tube Holds the cups on and lowers impedance. A 50 g tube is enough for many sessions; the 8 oz jar of Ten20, which is the clinical standard and easier to remove from hair, is $27.99. | Amazon | 1 | $9 |
| ESP32 DevKit (or Raspberry Pi Pico) For streaming from the ADS1299 board over USB later. Either board works; pick one ecosystem and learn it. | Amazon, Adafruit, SparkFun | 1 | $9 |
| Flush cutters, wire strippers, tweezers $7.99 for the stripper and flush cutter, plus $5.99 for a three-piece ESD tweezer set (Amazon B0BNNGC3Q2). | Amazon | 1 | $14 |
| Full-size breadboard, ×2, and jumper wires Two 830-point boards, two 400-point boards, and 120 jumpers for $7.99. Adafruit's single premium board is $5.95 and its contacts grip better. | Amazon | 1 | $8 |
| Gold cup EEG electrodes, set of 10 with DIN 1.5 mm leads $22.01 for ten, shipped free, in two to four weeks. The same thing on Amazon is about $60 for ten and arrives in days; the OpenBCI set is $44.99 and is usually sold out. Reusable, so clean them after each use. | AliExpress | 1 | $22 |
| Hobby servo (SG90), ×2 For muscle-to-motion. Two for $4.99, which is less than one from Adafruit. | Amazon | 1 | $5 |
| INA128 instrumentation amplifier (DIP-8), ×2 A two-pack is $9.99. TI's own INA128P is $18.99 each and the part is on a discontinuance notice, so the marketplace two-packs are grey stock; they work, but if one is noisier than the datasheet that is why. The AD620 or INA118 are interchangeable for our purposes. Get the through-hole DIP version for breadboards. | Amazon | 2 | $10 |
| LM386 audio amplifier, ×10 Drives a small speaker so you can hear spikes. Sold in tens; nobody sells one. | Amazon | 1 | $6 |
| Resistor and capacitor assortment $5.69 for 600 1% metal-film resistors, plus $9.99 for a 480-piece ceramic capacitor kit (10 pF to 10 µF, Amazon B0D2GVNDHY). 1% metal-film matters for the instrumentation amplifier's balance. | Amazon | 1 | $16 |
| Sewing pins or fine steel wire for insect electrodes A pin in the cockroach leg, another as reference. Backyard Brains sells proper ones if you want them. | Any store | 1 | $2 |
| Small 8 Ω speaker Adafruit's breadboard-friendly 8 Ω 0.2 W part is $1.85. Amazon's six-packs are $5.99 if you are not ordering from Adafruit anyway. | Adafruit | 1 | $2 |
| Temperature-adjustable soldering iron kit with solder, stand, and flux $11.99 for the iron, five tips, solder, a stand, and flux, which is everything Phase 1 needs. Its temperature dial is open-loop and its tips wear fast; the Pinecil V2 at $25.99 from Pine64 holds temperature properly and will outlast your degree, and it needs a USB-C PD supply you may already own. | Amazon | 1 | $12 |
| TL072 dual op-amps, ×10 For filters, the DRL circuit, and the audio stage of the SpikerBox. A ten-pack costs the same as two singles. The OPA2134 is quieter if you want to hear the difference. | Amazon | 1 | $6 |
| Total (prices drift; treat as a ceiling) | $192 | ||
Three notes on the list. Buy the through-hole (DIP) version of the instrumentation amplifierInstrumentation amplifier A precision differential amplifier with very high input impedance and high CMRR, built from three op-amps and sold as a single chip such as the INA128 or AD8232. Related: Differential measurementDifferential measurement Measuring the difference between two electrodes rather than one electrode against ground, so anything common to both cancels. , Common-mode rejection ratio (CMRR)Common-mode rejection ratio (CMRR) How much better an amplifier responds to a difference between its inputs than to a signal shared by both, in decibels; 100 dB means 100,000 times. , Input impedanceInput impedance How hard the amplifier's inputs are to push current into; it must be far higher than the electrode impedance or the signal is lost in the divider. . Glossary entry so it fits a breadboard. Get two 9 V batteries, not one, because a split supply makes the amplifier design much simpler. And buy an auto-ranging multimeter, which starts around $17; the cheaper meters range by hand and you will use this more than any other tool.
Most of the list is cheaper if you wait. The gold cup electrodesElectrode The conductor that turns ion currents in tissue into electron currents in a wire; its chemistry and contact quality set the noise you live with. Related: Silver/silver-chloride (Ag/AgCl)Silver/silver-chloride (Ag/AgCl) The standard electrode material for biopotentials, because its chemistry produces a stable, low-noise, low-drift interface with salty gel. , Electrode impedanceElectrode impedance How hard it is to push current through the skin-electrode contact, typically 5 to 50 kilohms with gel and megohms dry, higher at low frequencies. , Half-cell potentialHalf-cell potential The DC voltage that appears wherever a metal meets an electrolyte; two electrodes with different half-cell potentials produce an offset that can swamp the signal. . Glossary entry are 60 for ten on Amazon, for the same electrodesElectrode The conductor that turns ion currents in tissue into electron currents in a wire; its chemistry and contact quality set the noise you live with. Related: Silver/silver-chloride (Ag/AgCl)Silver/silver-chloride (Ag/AgCl) The standard electrode material for biopotentials, because its chemistry produces a stable, low-noise, low-drift interface with salty gel. , Electrode impedanceElectrode impedance How hard it is to push current through the skin-electrode contact, typically 5 to 50 kilohms with gel and megohms dry, higher at low frequencies. , Half-cell potentialHalf-cell potential The DC voltage that appears wherever a metal meets an electrolyte; two electrodes with different half-cell potentials produce an offset that can swamp the signal. . Glossary entry; the difference is three weeks. Order the slow things first and build the SpikerBoxSpikerBox Backyard Brains' small battery amplifier that lets you hear action potentials from a cockroach leg on a speaker; easy to build yourself. Related: Action potentialAction potential The brief, all-or-nothing voltage spike a neuron fires, about a millisecond long and about 100 millivolts tall across its membrane. , Instrumentation amplifierInstrumentation amplifier A precision differential amplifier with very high input impedance and high CMRR, built from three op-amps and sold as a single chip such as the INA128 or AD8232. . Glossary entry while they ship.
Tier 2: the real instrument
The fabricated ADS1299ADS1299 Texas Instruments' 8-channel, 24-bit biopotential front-end chip used in OpenBCI and many research amplifiers. Related: Delta-sigma ADCDelta-sigma ADC A converter that samples very fast with a crude 1-bit decision and averages, achieving 24-bit resolution at modest rates; what the ADS1299 uses., OpenBCIOpenBCI The open-source EEG hardware company whose Cyton (ADS1299) and Ganglion boards are the default hobby and research-lite amplifiers.. Glossary entry board (or an OpenBCIOpenBCI The open-source EEG hardware company whose Cyton (ADS1299) and Ganglion boards are the default hobby and research-lite amplifiers. Related: ADS1299ADS1299 Texas Instruments' 8-channel, 24-bit biopotential front-end chip used in OpenBCI and many research amplifiers. , BrainFlowBrainFlow A library that talks to OpenBCI and most consumer EEG headsets with one API, in Python and other languages. . Glossary entry Ganglion if you would rather buy and reverse-engineer), a USB oscilloscope, a signal generator, and supplies for making electrodesElectrode The conductor that turns ion currents in tissue into electron currents in a wire; its chemistry and contact quality set the noise you live with. Related: Silver/silver-chloride (Ag/AgCl)Silver/silver-chloride (Ag/AgCl) The standard electrode material for biopotentials, because its chemistry produces a stable, low-noise, low-drift interface with salty gel. , Electrode impedanceElectrode impedance How hard it is to push current through the skin-electrode contact, typically 5 to 50 kilohms with gel and megohms dry, higher at low frequencies. , Half-cell potentialHalf-cell potential The DC voltage that appears wherever a metal meets an electrolyte; two electrodes with different half-cell potentials produce an offset that can swamp the signal. . Glossary entry and a phantomPhantom A physical stand-in for tissue, such as saline gelatin with embedded wires, used to test an instrument against known signals. Related: CharacterizationCharacterization Measuring what your instrument actually does, such as its noise floor, bandwidth, and rejection, instead of assuming the datasheet. . Glossary entry head. This is Phase 2.
Tier 2
| Part | Where | Qty | Approx. |
|---|---|---|---|
| 3D printing access (campus makerspace) or a Bambu A1 mini Free on campus after the safety certification, which is the right answer for almost everyone. Buying your own is $299 and is worth it by Phase 2 only if you print weekly. | Marriott Library or Lassonde makerspace; Bambu Lab if buying | 1 | free |
| Conductive silicone or carbon-loaded filament for dry electrodes $29.99 per kilogram. Protopasta's conductive PLA is $49.99 and its resistivity is better characterized, which matters if you want to report impedance numbers. | Amazon | 1 | $30 |
| Eight reusable snap electrode pads and a fabric armband $7.99 for twenty reusable TENS pads with 3.5 mm snaps, plus elastic and hook-and-loop for the band. The reusable pads lose adhesion after a few dozen applications; disposable ECG electrodes give cleaner contact per session. | Amazon | 1 | $12 |
| Handheld oscilloscope with a built-in signal generator (FNIRSI DSO-510) $44.99 for 10 MHz, 48 MSa/s, and a DDS generator in one box, which replaces two purchases. 10 MHz is plenty for biopotentials and enough to eyeball SPI, but not enough for careful digital timing; the engineering building has real bench scopes for that. A Hantek 6022BE USB scope is $65.90 and a Rigol DHO800 is the one to want. | Amazon | 1 | $45 |
| OpenBCI Ganglion (4 channels), an alternative to building the ADS1299 board $624.99 and sold out as of this check, which is nearly three times what building the eight-channel board costs. It buys you a finished, documented instrument and a month of your life. The Cyton (8 channels) is $1,249 and also sold out; used ones appear on eBay. If you only want a board to reverse-engineer, the BioAmp EXG Pill is $34.49. | OpenBCI shop | 1 | $625 |
| Signal generator (cheap DDS module, or use the scope's built-in) Drives the phantom head dipoles at known amplitudes. Skip this if you bought the DSO-510, whose generator does the same job. | Amazon | 1 | $19 |
| Silver wire (0.5 mm, 99.99%) and household bleach for Ag/AgCl plating $15.75 for a metre, shipped free. Amazon's .999 fine silver is $22.99 for a foot. Do not substitute sterling; the copper in it corrodes. Chloriding in bleach or by electrolysis in saline turns bare silver into a proper Ag/AgCl electrode. | AliExpress, Amazon | 1 | $16 |
| Unflavored gelatin or agar, table salt, plastic bowl $14.17 for a pound of gelatin, which is about what a head-sized phantom takes, plus salt and a bowl. Saline concentration around 0.9% by weight matches tissue conductivity to within a factor you can calibrate. | Grocery store, Amazon | 1 | $16 |
| USB isolator (ADuM3160 based) Lets the board talk to a laptop on charger power without connecting the laptop's ground to you. It is full-speed only (12 Mbps), which is fine here. Adafruit's is $34.95 with better isolation ratings and documentation. Batteries are still simpler. | Amazon | 1 | $9 |
| Your ADS1299 board, fabricated and assembled by JLCPCB (5 boards, 2 assembled) The chip dominates. The eight-channel ADS1299IPAG is $69.82 each from TI in single quantity. JLCPCB's own charges are small (bare boards about $2, an $8.18 economic assembly setup, a $1.53 stencil, $0.0016 per joint); the rest is the other components and shipping. The four-channel ADS1299-4PAGR is $37.10 at LCSC and brings the whole order to about $150, and four channels cover every Phase 3 project. Order two assembled so one can die. | JLCPCB | 1 | $215 |
| Total (prices drift; treat as a ceiling) | $987 | ||
The board dominates the cost because the ADS1299ADS1299 Texas Instruments' 8-channel, 24-bit biopotential front-end chip used in OpenBCI and many research amplifiers. Related: Delta-sigma ADCDelta-sigma ADC A converter that samples very fast with a crude 1-bit decision and averages, achieving 24-bit resolution at modest rates; what the ADS1299 uses. , OpenBCIOpenBCI The open-source EEG hardware company whose Cyton (ADS1299) and Ganglion boards are the default hobby and research-lite amplifiers. . Glossary entry chip is 37.10 and halves the order; four channels run every Phase 3 project, and you give up the eight-channel armband and the denser montagesMontage The particular arrangement of which electrodes are subtracted from which, such as referential, bipolar, or average reference. Related: Reference electrodeReference electrode The electrode every other channel is measured against; there is no neutral spot on the head, so the choice shapes every trace. , Common average referenceCommon average reference Re-referencing every channel to the mean of all channels, which approximates a neutral reference when electrodes cover the head well. , Surface LaplacianSurface Laplacian Subtracting the average of neighbouring electrodes from each electrode, which sharpens spatial detail and suppresses distant sources. . Glossary entry. The table’s total adds the Ganglion, which is an either-or with the board, so the build path is about $215 of it. A campus makerspace covers the 3D printing for free once you have done its orientation.
Buying the Ganglion instead has stopped being the cheap way in. It is 1,249. Watch eBay for a used one, or build.
Tier 3: borrowed
The nanofab, a lab’s rig, the machine shop, a bench oscilloscope in the engineering building. Phase 6 lives here, and pieces of Phase 2 do too. The only way in is the research ladder, which is why it starts in Phase 1.
Tools you will wish you had bought earlier
A cheap USB microscope for inspecting solder joints. A set of test-lead adapters (BNC to alligator, 3.5 mm to touch-proof) because half of biopotential work is connectors. A label maker. Small parts drawers. A notebook that lies flat.
Renting the output instead of owning the machine
For anything you cannot make on campus: PCBsPrinted circuit board (PCB) The board that holds and connects your components; designing one is how a breadboard prototype becomes an instrument. Related: KiCadKiCad Free, open-source software for drawing schematics and laying out printed circuit boards. , JLCPCBJLCPCB A Chinese board house that fabricates and assembles small-run PCBs for a few dollars, the standard for student projects. . Glossary entry and assembly from JLCPCBJLCPCB A Chinese board house that fabricates and assembles small-run PCBs for a few dollars, the standard for student projects. Related: Printed circuit board (PCB)Printed circuit board (PCB) The board that holds and connects your components; designing one is how a breadboard prototype becomes an instrument. . Glossary entry or PCBWay for a few dollars; laser-cut or waterjet metal and acrylic from SendCutSend; resin, nylon, or metal prints from JLC3DP or Craftcloud. Most student hardware projects never need a machine of their own.