What Is Neuro PlayGround Lite?

This is Neuro PlayGround Lite, a pocket-sized bio-physiological sensing device with a 3-6-channel BioAmp that records EEG (brain waves), ECG (heartbeats), EOG (eye movements), and EMG signals (muscle activity). It streams data over multiple wireless protocols like BLE, Zigbee, Wi-Fi, or Thread for mesh networking It also offers FeatherWing-style expandability for plug-and-play HCI and BCI projects.

NPG Lite Technical Overview

Hardware Specifications

NPG Lite Pinout Diagram

Pin Descriptions

Bio-Amp Input Pins

Standard Feather Pins

GPIO Expansion Pins

Power Specifications

Choose Your NPG Lite Kit

Each NPG Lite kit includes the main board plus a specialized Playmate expansion board that adds unique capabilities. Choose the kit that matches your project needs:

Understanding Playmate Expansion Boards

Proto Playmate (Explorer Kit)

Features:

• Large prototyping area for custom circuits
• Standard 2.54mm electrode headers
• ON/OFF slide switch
• QWIIC port for I2C sensors

VibZ Playmate (Ninja Kit)

Features:

• Vibration motor for haptic feedback
• Buzzer for audio alerts
• Standard 2.54mm electrode headers
• ON/OFF slide switch
• QWIIC port for I2C expansion

VibZ+ Playmate (Beast Kit)

Features:

• All VibZ Playmate features
• Additional 3-channel BioAmp (total 6 channels)
• Standard 2.54mm electrode headers
• Extended electrode connectors
• Toggle switches for Sequential/Referential montage

Playmate Pinout & Connections

Standard Electrode Connections (All Playmates)

VibZ+ Additional Channels

Playmate Comparison Table

Hardware Required

For this tutorial, we’ll be using Neuro PlayGround Lite Ninja pack

• Neuro PlayGround Lite (ESP32-C6 BioAmp board)
• VibZ Playmate (electrode hub)
• Gel electrodes (3 pcs minimum)
• BioAmp snap cables (3 cables minimum for single channel setup)
• LiPo battery (included in Ninja/Beast packs)

Additional Items

• NuPrep skin-prep gel (Optional)
• Alcohol swabs
• A laptop with USB-C port

Video Tutorial

Follow along with our comprehensive video tutorial:

Additional Resource: Instructables Guide - Your First Steps to HCI/BCI Projects

Step 1: Skin Preparation

First, let’s prepare your skin surface before applying the electrodes.

Preparation Steps:

(Please refer to the images below for electrode placement locations)

1. Apply NuPrep Skin Preparation Gel to electrode placement areas
2. Clean with alcohol swabs after gel application

Electrode Locations:

• EMG: Flexor carpi radialis muscle (forearm)
• ECG/EKG: Chest or wrist placement
• EEG: Forehead and behind both ears

Step 2: Connection Setup

Time to connect BioAmp Snap Cables to NPG Lite and place electrodes.

Cable Connections:

• Channel 1: A0P and A0N (EMG - forearm)
• Channel 2: A1P and A1N (ECG/EKG - chest or wrist)
• Channel 3: A2P and A2N (EEG - head)
• Reference: One cable for common reference (bony part behind the ear)

Electrode Placement:

⚠️ Important Notes:

• You can use any of the channels for EEG, ECG, EOG, or EMG
• The reference electrode is shown separately in each image below, but we'll be using a common reference(EEG placement) for all channels.

EMG Placement:

• Place positive and negative electrodes on your forearm muscle
• Place reference at the bony part on your hand

ECG/EKG Placement:

• Negative: Left wrist or chest under left arm
• Positive: Right wrist or chest under left arm
• Reference: Bony part on your hand or chest under right arm

EEG Placement:

• Positive: Forehead (between FP1 and FP2)
• Negative: Behind one ear (bony part)
• Reference: Behind the other ear

EOG Placement:

For future EOG projects, refer to the placement image below:

• Positive: Above any eye
• Negative: Below any eye
• Reference: Bony part behind the ear

Step 3: Pre-Visualization Checks

Before starting data visualization, ensure:

Checklist:

• [ ] Skin is thoroughly prepared
• [ ] Laptop is NOT connected to charger
• [ ] You're at least 5 meters away from AC appliances
• [ ] All electrodes are properly placed and connected
• [ ] NPG Lite is fully charged and powered-ON

Step 4: Power On Your NPG Lite

Now, let’s fire up the NPG Lite by toggling the switch on the VibZ Playmate.

Step 5: Flash the Firmware

We’ll use the NPG Lite Flasher, a user-friendly tool to flash firmware onto your ESP32-based NPG Lite.

Download the Flasher

1. Download the NPG Lite Flasher from: github.com/upsidedownlabs/NPG-Lite-Flasher
2. Install and launch the application

Flash the Firmware

1. Connect your NPG Lite via USB-C cable
2. Choose the firmware you'd like to flash:
   • BLE (for this tutorial)
   • Wi-Fi
   • Serial
   • Custom
3. Identify the correct port
4. Click "Flash"

After Flashing

Once the firmware is flashed:

1. Unplug the NPG Lite from your laptop
2. Disconnect the laptop's charger to minimize AC noise

LED Status Indicators (Chords BLE Firmware)

The NPG Lite features RGB LEDs that provide visual feedback for connection status:

• 🔴 Red LED: Device is powered on but disconnected
• 🟢 Green LED: Device is connected to Chords interface
• 🔵 Blue LED: Device is connected and actively streaming data

Haptic Feedback (VibZ/VibZ+ Playmates)

The VibZ and VibZ+ Playmates also provide vibration feedback:

• Single vibration: Device successfully connected
• Double vibration: Device disconnected

Step 6: Data Visualization

Finally, let’s visualize your bio-signals!

Open Chords Web Interface

• Click on Chords-Web on NPG Lite Flasher

• or, Go to: chords.upsidedownlabs.tech

Use a Chromium-based browser (Chrome, Edge, etc.)

Connect Your Device

1. Click "Visualize Now"
2. Select "NPG-Lite" from the bottom options
3. Ensure Bluetooth is enabled (no manual pairing needed)
4. Click "Connect" to scan for devices
5. Select your NPG Lite from the list

Configure Channels & Filters

1. Click the settings icon to select all channels
2. Apply appropriate filters:
   • Channel 1: EMG filter
   • Channel 2: ECG/EKG filter
   • Channel 3: EEG filter
3. Enable notch filter (50Hz or 60Hz based on your region)

Interface Features

This interface allows you to:

• ✅ Select channels you'd like to visualize
• ✅ Adjust zoom level for better signal viewing
• ✅ Play/pause the data stream for analysis
• ✅ Apply bandpass filters and notch filters
• ✅ Record data for all channels and save in CSV format

When you’re done, click "Disconnect".

Troubleshooting

Common Issues & Solutions

Device Not Connecting

• Check USB-C cable connection
• Install ESP32 drivers if on Arduino
• Try different USB port
• Try putting your device to BOOT mode (BOOT + RESET) to flash the firmware

Poor Signal Quality

• Clean skin with alcohol wipes before electrode placement
• Press electrodes firmly to ensure good gel contact
• Minimize movement during recording
• Check all connections are secure
• Make sure you're at least 5 meters away from AC appliances

Bluetooth Issues

• Bluetooth should be enabled on the system
• Ensure BLE firmware is flashed correctly
• Check device is powered on (LED indicators)
• Clear browser cache and reload
• Move the device closer to the system (within 10 meters)

If you still face issues connecting to your device via bluetooth, follow these steps and try again:

• Go to you chromium based browser
• Type chrome://flags in the search bar and hit enter
• Search for Bluetooth and enable everything related to Web Bluetooth
• Restart your browser
• Try connecting again

Safety Guidelines

⚠️ Important Safety Notes

• Never exceed 3.3V input on GPIO pins
• Single-use electrodes: Don't share between users
• Medical disclaimer: Not for medical diagnosis or treatment
• Keep away from liquids and operate within 0-40°C (32-104°F)

What’s Next?

This concludes the NPG Lite Getting Started Tutorial, Get Yours today!

Learn More:

• Official Documentation: docs.upsidedownlabs.tech
• Join our Discord: discord.gg/SzYRVz8xRw
• GitHub Projects: github.com/upsidedownlabs

Keep experimenting and building amazing HCI and BCI projects! 🚀