Upside Down Labs
Bio Sensing
Feather
Back this project to help bring it into existence.
Funding ends on Sep 11, 2025 at 04:59 PM PDT.
Neuro PlayGround Lite (NPG Lite) is a multichannel Feather-form-factor wireless bio-physiological signal acquisition board. It can be used for Electrocardiography (ECG), Electromyography (EMG), Electrooculography (EOG), or Electroencephalography (EEG). Its compact footprint and hassle-free setup ensure portability, quick deployment, and a clutter-free experience, making it ideal for research, education, and wearable applications.
Users can expand NPG Lite’s capabilities with add-on Playmate boards and 3rd party FeatherWing boards. Its extensive compatibility lets you equip your device with features like a vibration motor for haptic feedback, a buzzer for audio feedback, and I2C connectivity, making it highly versatile for a wide range of applications. It leverages our powerful open source, cross-platform Chords software suite (Chords-Web, Chords-Python, Chords LSL Connector, and Chords LSL Visualizer), letting users visualize captured bio-physiological signals in real-time, apply filtering, perform FFT analysis, and much, much, more. Because of its expandability, wide array of applications, and robust networking capabilities (using Bluetooth, Zigbee, Wi-Fi, or Thread for mesh networking), NPG Lite lets you capture bio-physiological signals how you want and where you want it. To simplify the process to flash your NPG Lite board we have also created a dedicated flasher tool called NPG-Lite-Flasher, it allows you to download pre-build firmware binaries from GitHub and you can flash your own binary files as well.
NPG Lite, with its multi-channel BioAmp, wireless connectivity, battery operation, and expansion interface, allows users to create HCI and BCI applications with ease. We’ve created four demos leveraging ECG, EMG, EOG, and EEG singals to inspire you, but the possibilities cover so many more use cases.
This is a human-computer interface (HCI) that uses 3-channel EMG data to detect muscle signals from the left hand, right hand, and chest to control virtual musical instruments. When muscles contract, each channel triggers a distinct sound effect, transforming your body into an organic orchestra.
This demo focuses on capturing electrocardiogram (ECG) signals to calculate heart rate using Neuro PlayGround Lite and displaying them in a Chrome-based browser on a mobile phone in real-time via a Bluetooth LE connection.
Instead of using the keyboard, you can control a game simply by blinking. The setup detects EOG signals from the eyes, sends the data over Bluetooth LE to the PC, detects eye blinks, and then takes the eye blink as a trigger to emulate the spacebar keystroke. You can configure the code to simulate any other keystroke as well.
This demo showcases a brain-computer interface (BCI) application that utilizes EEG (electroencephalography) signals to operate an interactive bubble-popping game in a web browser. The system identifies beta wave activity (12–30 Hz), indicating concentration and attention levels. Bubbles appear and pop as the user maintains focus, but they cease to pop when concentration wanes.
We are committed to providing ready-to-use, open-source applications that showcase the true potential of NPG Lite:
Control a Custom BLE Car with EMG + EEG:
Drive a Bluetooth-enabled car using both muscle and brainwave signals.
EEG Smart Plug Control:
Toggle any AC appliance ON or OFF through mind-generated EEG signals.
EEG + IR Remote Control for Appliances:
Manage devices like TVs or fans using EEG combined with infrared signaling.
EEG + ECG Assistive Meditation App:
EEG for brain data and ECG for HRV analysis to guide and enhance mindfulness through real-time brain-heart coherence.
ECG-Based Heart Ailment Detection:
Real-time cardiac health monitoring and anomaly detection using our robust ECG processing software.
EXG for supportive tech
Using single channel EXG for blink detection, focus, and jaw clinching detection for supportive tech.
EMG gesture recognition
Multi-channel EMG based gesture recognition interface for AR, games, and prosthetics control.
Some of the firmware available to use with NPG-Lite right away includes,
| Firmware | Description |
|---|---|
| NPG-Default | Default program to show Visual, Auditory, and Haptic feedback on NPG attached to VibZ or VibZ+ playmate |
| Serial-FFT | Calculate FFT & Band Power of single channel EEG and print on Serial |
| BLE-Server | Bluetooth Low Energy (BLE) server to notify client with real-time NPG data |
| BLE-Client | BLE client to take notification from server and trigger GPIO |
| BLE-BCI-Server-Toggle | BLE server to notify client based on EEG band (beta) power triggers |
| IR-LG-Receive | InfraRed (IR) receiver code to identify LG AC remote button commands |
| IR-LG-Send | IR signal sending example code to control LG AC to toggle ON/OFF using user button |
| BCI-IR-Send | Brain Computer Interface (BCI) to toggle LG AC ON/OFF using EEG band (beta) power |
| BLE-BCI-Car | BLE client that receives notifications from the server and triggers GPIO to control the car |
| BLE-BCI-Car-Remote | BCI remote (server) to drive the BLE car using EEG band (beta) power and EMG (envelope) data |
| BCI-Blink-Serial | Brain Computer Interface example sketch for Double blink and focus detection. |
| BCI-Blink-BLE | Brain Computer Interface to control a menu of options using Double blink and focus detection for ALS patients. |
| Gyro-Motion-Detection | MPU6050 sketch to stream 3-axis accelerometer data and send 4 keystrokes to play video games on laptop. |
| Blinky-Keys-Serial | Detects double and triple blinks from EOG signals using high‑pass and notch IIR filters with envelope detection. |
| Blinky-Keys-BLE | Implements a BLE HID keyboard that sends right‑arrow on double blinks and left‑arrow on triple blinks to control slides in a presentation. |
| BCI-BLE-Gamepad | Implements a BLE gamepad that reads EEG and EMG signals to control games on Windows, using focus and muscle contractions. |
Check out NPG-Lite-Firmware repo for all the cool demos in the making. To use NPG with Chords software suite, you can choose any of the following firmware.
| Firmware | Description |
|---|---|
| NPG-LITE | NPG Lite firmware for Chords Serial interface |
| NPG-LITE-BLE | NPG Lite firmware for Chords BLE interface |
| NPG-LITE-WIFI | NPG Lite firmware for Chords WIFI interface |
A Rust based flashing program for NPG Lite.
https://github.com/upsidedownlabs/NPG-Lite-Flasher
A NextJs based tool for BioAmp data visualization, processing, and recording.
https://chords.upsidedownlabs.tech/
A Python based tool for BioAmp data visualization, processing, analysis, and recording.
https://github.com/upsidedownlabs/Chords-Python
A Rust based program to stream NPG data over Lab Streaming Layer.
https://github.com/upsidedownlabs/Chords-LSL-Connector
A Rust based program to visualize data from any LSL stream.
https://github.com/upsidedownlabs/Chords-LSL-Visualizer/
NPG Lite Playmates are add-on boards that expand the functionality of the NPG Lite system.
The Proto Playmate includes a prototyping area, electrode connector interface, ON/OFF slide switch, and a QWIIC port.
The VibZ Playmate adds haptic and auditory feedback via a vibration motor and buzzer, along with an electrode connector interface, ON/OFF slide switch, and QWIIC port.
The VibZ+ Playmate builds on the VibZ by adding an additional 3-channel BioAmp, enabling a total of 6 channels. It is designed for applications that require higher-resolution biosignal input or more spatial coverage.
If you’re comfortable with soldering and only need a 3-channel wireless BioAmp, the Explorer kit is a great choice. For the most complete NPG Lite experience right out of the box, go with Ninja. If you require additional channels for full-body signal acquisition or advanced experimentation, the Beast Pack offers the most comprehensive configuration.
| Pack Options | Explorer | Ninja | Beast |
|---|---|---|---|
| NPG Lite | Included | Included | Included |
| Playmate type | Proto | VibZ | VibZ+ |
| Channel Count | 3 channels | 3 channels | 6 channels |
| Gel Electrodes | 12 pieces | 24 pieces | 24 pieces |
| Snap Cables | 7 pieces | 7 pieces | 13 pieces |
| Alligator Cables | 5 pieces | 5 pieces | 8 pieces |
| Battery Cable | Included | Included | Included |
| LiPo battery | Not Included | Included | Included |
| 3D Printed Case | Not Included | Included | Included |
| USB Cable | Not Included | Included | Included |
| Cost | $99 | $149 | $199 |
If you want additional accessories and consumables to do more experiments you can buy them along with your NPG Lite kits.
BioAmp Accessory Bundle if you want dry electrode bands (ECG, EMG, & EEG) and need a skin prepration kit for your experiments.Gold Cup Electrodes Kit (10 pack) is best when you want to record EEG from areas where your gel electrodes are not reachable.Tab Hydrogel Electrodes (100 pack) provides a larger surface area with hydro-gel interface.Alligator Cables (10 pack) is required if you want to connect Tab Hydrogel Electrodes to your NPG Lite.Baby Gel Electrodes (100 pack) are good for all your EXG requirements. They are generic small size pediatric electrodes with an outer foam adhesive layer and gel based conductive center.Snap Cables (10 pack) are required if you want to connect Baby Gel Electrodes to your NPG Lite.| Neuro PlayGround Lite | spiker:bit | Human SpikerBox | Ganglion | |
|---|---|---|---|---|
| Manufacturer | Upside Down Labs | Backyard Brains | Backyard Brains | OpenBCI |
| MCU / Dev Board | ESP32 C6 | Micro:bit v1 & v2 | STM32L433 | Simblee (Obsolete) |
| Biopotential(s) | EXG | EXG | EXG | EXG |
| No. of Channels | 3ch - 6ch | 1ch | 2ch | 4ch |
| ADC Resolution | 12bit | 12bit | 12bit | 24bit |
| Wireless capabilities | WiFi 6, BLE 5, Thread, & Zigbee | BLE | NA | BLE (unknown) |
| Arduino Support | Excellent | Poor/Unofficial | Poor/Unofficial | Obsolete |
| MicroPython Support | Excellent | Limited | No | No |
| Wearable | Yes | Yes | No | No |
| Rechargeable Battery Support | Yes (LiPo) on-board charger | No (2xAA) | No (9V) | Yes (LiPo) external charger |
| USB Support | USB-C (Power, charging, and flashing) | Micro-B (Power & flashing) | USB-C (Data transfer) | No USB |
| ESD Protection | USB & User | USB & User | USB & User | User |
| Expansion/Add-on support | Yes (Playmates, Feather Wings, & QWIIC) | Yes (Grove & Header Pins) | No | No |
| Base cost per Channel | $33 | $99 | $150 | $157 |
| Usable Kit cost | $99 | $128 | $300 | $700 |
At Upside Down Labs, we believe in the power of open source to drive innovation, foster collaboration, and empower creators. Neuro PlayGround (NPG) Lite embodies this philosophy by being fully open source. Its firmware is readily available at NPG Lite Firmware, and our supporting tools, including Chords-Web, Chords-Python, and Chords LSL Connector, are released under open-source licenses. Additionally, we will share schematic diagrams as soon as devices reach the hands of our backers.
But we won’t stop there. Once we achieve significant milestones in our journey, such as reaching a broader community of users and supporters, we will release all hardware design files as open source. This step will enable enthusiasts, researchers, and developers to contribute to and build upon our work, creating a thriving ecosystem around NPG Lite.
By supporting this project, you’re helping advance open, accessible tools for bio-physiological signal acquisition. Your backing contributes to the development of flexible, community-driven technology that empowers research, experimentation, and innovation.
You can find the extensive documentation about NPG Lite on our documentation site.
For any support requests, you can create issues on our GitHub repositories, for direct conversation we recommend to join our Discord channel.
We’ve already produced over 100 NPG Lite prototypes across four design iterations, each tested extensively in real-world conditions. The product has consistently received positive feedback, both for its functionality and manufacturing quality.
For production, we source high-quality PCBs from a trusted supplier in China. Final assembly is handled in-house using our own pick-and-place machine, giving us full control over quality assurance and lead times. This hybrid approach ensures we can scale efficiently while preserving the build quality our testers have come to expect.
After our production run is complete, we will box everything up and send it along to Crowd Supply’s fulfillment partner, Mouser Electronics, who will handle distribution to backers worldwide. You can learn more about Crowd Supply’s fulfillment service under Ordering, Paying, and Shipping in their guide.
As with any new hardware product, there is always some risk of manufacturing or supply chain delays. To minimize these risks, we’ve partnered with experienced, vetted suppliers and selected components with stable, long-term availability. In the event of any delays, we’re committed to transparent, timely communication with all backers. Our team also brings a proven track record, having successfully delivered previous BioAmp products on time and to specification.
We believe in complete transparency. Here’s what you need to know:
NPG Lite is designed to be user-friendly and comes with extensive documentation and support channels. However, users may encounter challenges related to initial setup, firmware flashing, or electrode placement, especially if they are new to biosignal acquisition hardware. We recommend reviewing our guides and reaching out via GitHub or Discord for any troubleshooting or technical questions.
We have already manufactured and tested over 100 NPG Lite devices in-house, demonstrating a reliable and repeatable process. Our PCBs are sourced from a trusted supplier in China, and we maintain close communication to ensure consistent quality and timely delivery. While we do not anticipate major issues, global supply chain disruptions or unexpected component shortages could cause delays. We are committed to transparency and will promptly update backers if any manufacturing challenges arise.
Final assembly is performed in-house using our own pick-and-place machine, which allows us to maintain strict quality control and minimize errors. Each device undergoes thorough testing before shipment to ensure functionality and reliability. While the risk of assembly defects is low, any issues identified during testing will be resolved before fulfillment. Should any problems occur after delivery, we will provide support and replacements as needed.
We will keep backers informed at every stage of production and notify you immediately if we encounter any delays or challenges.
Produced by Upside Down Labs in New Delhi, India.
Sold and shipped by Crowd Supply.
Includes everything you need to get started: 1 NPG Lite board, 1 Proto Playmate, 7 snap cables, 5 alligator cables, 12 gel electrodes, and 1 battery connector
For those who want a pre-assembled system in a 3D printed case with battery, haptic & auditory feedback: 1 NPG Lite board, 1 VibZ Playmate, 7 snap cables, 5 alligator cables, 24 gel electrodes, 1 LiPo battery, 1 Type-C cable, and 1 3D printed case
Perfect for those who want a pre-assembled system in a 3D-printed case with battery, 6 channels, haptic & auditory feedback: 1 NPG Lite board, 1 VibZ+ Playmate, 13 snap cables, 8 alligator cables, 24 gel electrodes, 1 battery connector, 1 Type-C cable, 1 3D printed case
Accessory bundle with dry electrode bands and skin preparation kit for recording the best quality data. Comes with 1 muscle BioAmp band, 1 heart BioAmp band, 1 brain BioAmp band, 9 grams of NuPrep skin prep gel, 15 grams of Ten20 conductive paste, 12 baby gel electrodes, 100 alcohol swabs, 100 cotton swabs
10 gold-plated electrodes with 100 cm wire & 15 grams Ten20 conductive paste for the highest quality EEG recordings
100 highly conductive full-surface hydrogel electrodes for general-purpose EXG recordings. Connect with alligator cables (not included)
10 alligator-style BioAmp cables of different colors with 100 cm wire to connect gel electrodes for general-purpose EXG recordings (gel electrodes not included)
100 highly conductive small-size pediatric gel electrodes for general-purpose EXG recordings that snap directly to BioAmp snap cables (not included)
10 snap BioAmp cables of different colors with 100 cm wire to connect gel electrodes for general-purpose EXG recordings. (gel electrodes not included)
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