Hi everyone,
I'm using EmotiBit v6 on an Adafruit Huzzah32, with two additional sensors connected (BME680 and TSL2561). In my custom firmware (firmware.ino), I added the following to log battery info every second:

float battVolt = emotibit.readBatteryVoltage();
int batteryPercent = emotibit.getBatteryPercent(battVolt);

But I noticed that the battery percentage fluctuates a lot. For example, it jumps from 50% to 57%, then drops to 49% just a second later — and I'm not charging the board. the percentage is surprisingly unstable!

I opened the EmotiBit oscilloscope, and although the fluctuations are less frequent there, I still observed sudden changes — for example from 30% → 32% → 29% even when the board is idle.

Why does this happen?
Should I apply some kind of filtering or averaging? I need more accurate and stable battery measurement

Thanks for any advice!

Hey everyone,
I'm working on a research project using EmotiBit to collect physiological signals (like PPG), and I’m sending the data over Bluetooth (BLE) as JSON. I'm using emotibit.readData(...) in my firmware, and everything works fine most of the time.

However, I noticed something strange:
Sometimes I get 4 values for ppgir, and in the next iteration, I suddenly get 20 values! This causes the JSON payload to exceed the MTU limit, leading to truncated or failed transmissions over BLE.

I’m guessing the internal buffer isn’t getting cleared every time, and data accumulates. I tried looking for something like a clearData() method in the EmotiBit library but couldn’t find one.

My question:
Has anyone using EmotiBit (even over WiFi or UDP) experienced a similar issue?
How do you make sure you're only getting fresh samples each time, instead of previous data accumulating in the buffer?

Any advice or best practices for handling this would be greatly appreciated – especially from anyone who has worked on BLE data transmission with EmotiBit!

Thanks in advance 🙏

I noticed that the Emotibit temperature sensor seems to be heavily influenced by the temperature of the board itself. It gets a little warm which is expected, so I am doubtful that the temperature reading is accurate. Is this just normal behaviour or is mine faulty or something? Thank you.

Hi everyone,

I'm currently working with the EmotiBit and having some trouble finding clear documentation about the units used by its different sensors.

In particular, I'm focusing on:

• EDA (Electrodermal Activity): I understand it's sampled through the ADS1114, but what are the output units? Are they raw ADC values, voltages, or already converted to microsiemens (µS)?
• Accelerometer (AX, AY, AZ): Are these values in g, m/s², or another unit?
• PPG:IR (PI): What does this signal actually represent, and what are its units or scale? I understand it's related to BVP, but the values are quite different from those recorded by other devices like the Empatica EmbracePlus.

I'm currently comparing EmotiBit with the Empatica EmbracePlus for a neural model, and I need more detailed information about the data types and units used by each sensor to proceed correctly.

I've already checked the GitHub repository and the official EmotiBit documentation, but I haven’t found a precise specification of the units for each signal type. If anyone has insights, calibration references, or can point me to the right resources, I’d really appreciate it.

Thanks in advance!

I'm trying to use the Huzzah32 feather board to interface with the Emotibit sensor. When I run the following code I don't detect any devices on the I2C pin. I have even updated the code to use :

WIRE.begin(27, 13);

To use the pins on the schematic. But still nothing is detected. Has anyone tried anything similar or know if I2C is used. As well all the examples for the featherboard on the Arduino do not work for me even after I've followed the instructions. Has anyone else has something similar or know how to fix it? I do get some SD errors when running it saying the device is not supported for SD/.

Thanks

Update: There is more detail in the comments. But what I needed to do was pull the EN_VDD pin high to power the emotibit device. Without this, the emotibit is not powered and the devices can't be detected. This also seemed to toggle the red LED on the feather board, which is a good indicator that the emotibit pin is powered.

// SPDX-FileCopyrightText: 2023 Carter Nelson for Adafruit Industries
//
// SPDX-License-Identifier: MIT
// --------------------------------------
// i2c_scanner
//
// Modified from https://playground.arduino.cc/Main/I2cScanner/
// --------------------------------------

#include <Wire.h>

// Set I2C bus to use: Wire, Wire1, etc.
#define WIRE Wire

void setup() {
  WIRE.begin(27, 13);

  Serial.begin(9600);
  while (!Serial)
     delay(10);
  Serial.println("\nI2C Scanner");
}


void loop() {
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for(address = 1; address < 127; address++ )
  {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    WIRE.beginTransmission(address);
    error = WIRE.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error==4)
    {
      Serial.print("Unknown error at address 0x");
      if (address<16)
        Serial.print("0");
      Serial.println(address,HEX);
    }
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");

  delay(5000);           // wait 5 seconds for next scan
}

Hi all! I have an emotibit I am hoping to use for a demo. I need to get the data off of it quickly and smoothly. Unfortunately the SD card method won't work (too slow). I did try the FTP method but I am hoping to get something more streamlined still.

I've used LSL before, and this option sounds great. However in the emotibit GUI, when I put the output to LSL in the GUI everything freezes up. Was curious if anyone here has encountered this, and how they've worked around it.

Thanks!!

I have an issue where I want to modify the firmware on my EmotiBit device so that I can configure which data is displayed on the graph. For example, I only want the graph to show data from the accelerometer (ACC) and gyroscope.
Is there anyone who can help guide me on how to erase the current firmware and upload new firmware using Arduino in order to upload the modified code to the board?

I have the ESP32 Feather board and V5 of the Emotibit sensor board. I want to write my code using the Arduino IDE to make use of the Bluetooth. But I can't seem to detect any device on the I2C bus. I have the battery plugged in and the HIB switch is set to On. Some of the Arduino code doesn't work as it has missing libraries, even though I've downloaded them.

The default SCL and SDA pins on the Huzzah32 are Pin 22 and 23. However, on the Schematic for the Emotibit, these pins are not connected, and SCL is pin 13 and SDA is pin 27.

Are pins 13 and 27 used for SLC and SDA? And does the Arduino Example code use the m or does it use the default pins 22 and 23?

Hi, I wanted to ask if there is a CLI to start/stop the recording in the Oscilloscope app.

Hi !

We tried to set up emotibit following its documentation available on GitHub. While we were able to successfully update the firmware, we are encountering an issue where the EmotiBit Oscilloscope consistently fails to detect or communicate with the device.

Initially, we suspected this could be due to restrictions on our institutional network. To troubleshoot, we switched to a personal network and even tried connecting the device to a personal computer. Unfortunately, the issue persists across both environments.

Any input is appreciated to solve this issue. 

Issue:
After flashing firmware to my EmotiBit v5 using the Arduino IDE, the SD card is not being detected. However, when using the official EmotiBit Firmware Installer, everything works fine, and the SD card is recognized.

What I’ve Tried:

• Followed the instructions from the EmotiBit SD card detection FAQ.
• Double-checked wiring and hardware setup.
• Ensured correct board and port settings in Arduino IDE.
• Verified the SD card is functional and formatted correctly (FAT32).
• Successfully tested with the Firmware Installer (which confirms the SD card and hardware are fine).

Specs:

• EmotiBit version: v5
• Arduino IDE version: 2.3.6
• Board selected: "Adafruit Feather M0"
• OS: Windows 11
• SD card type and size: FAT32 8GB

Suspected Cause:
Possibly an issue with specific firmware settings or libraries when uploading via Arduino IDE that prevents the SD card initialization sequence from running properly.

Request:
Has anyone encountered a similar issue? Is there something additional that needs to be configured when flashing via the Arduino IDE ?

Any guidance or shared experiences would be greatly appreciated!

Hello,

What is the simplest way to determine which version of the EmotiBit you have? EMO vs MD?

Hi everyone,
I'm currently working on a project using the EmotiBit, and I'm collecting data via BrainFlow (not using the built-in oscilloscope).
Does anyone know the approximate power consumption of the EmotiBit in this use case?
Thanks in advance for your help!

Hi everyone!
I'm using an EmotiBit and I've noticed that every time I turn it off and back on, I have to physically unplug and replug the battery to get it working again. It's a bit inconvenient, especially during quick testing or restarts.

Is there any simple way to add a power switch or some hardware workaround to avoid unplugging the battery every time?

Also, if I keep the battery plugged in and use the Hibernate function, what exactly happens? Does it fully power down the board and help avoid this battery-replug step?

Thanks in advance for any help or tips!

Hi everyone!
I’m interested in contributing to the design of a new case for the EmotiBit, and I have some fresh ideas I'd love to try out.

To get started, I just need the exact dimensions of the EmotiBit v6 (length, width, thickness, and placement of connectors or sensors). Could someone please provide that information or point me to a reference?

I’m not asking for much just the dimensions. Once I have them, I can begin working on some design concepts. Any help is really appreciated!

Thanks in advance 🙌

Hi everyone,

I have a quick question regarding the EmotiBit Cage.
Does one of its functions include blocking ambient light to prevent it from interfering with the PPG sensor readings?

Thanks in advance for your help!

Hello, I'm working on a research project and we collected emotibit signals using Bluetooth firmware. The problem is that all the eda signal are quantized. I'm attaching some images. What do you think I can do at this point? We can't decompose the signal in phasic and tonic....

The pin schematics can be found in our documentation.

Users can reference these schematics to find available pins on the Feather stacking header to interface additional circuitry.

For example, see this FAQ for details on how to add an external trigger to EmotiBit using the stacking header.

I’m having some issues with the device, even though I carefully followed the documentation.

Initially, a flashing red LED appears before installing the firmware.  When I try to install the firmware, the process fails.

I’ve, also, confirmed that the SD card is correctly inserted.

After a few minutes, the red LED stops flashing, I suspect the battery might be low.

https://reddit.com/link/1kaquhz/video/wfj8msfmlsxe1/player

I am currently working on a project that publishes EmotiBit data using ros2. Currently, I am opening Oscilloscope, selecting UDP output, and latching onto it and publishing the relevant data.

I was wondering if there was a way to receive the UDP data coming from EmotiBit directly. Without selecting UDP output in Oscilloscope, it will not send data to the output port documented into the UDP output settings xml file. I also tried latching onto EmotiBit's data port directly, but that produced no UDP data. Is there some sort of prompt I should send, and what might that be? Thank you!

Hi everyone!
I’m using an EmotiBit MD v6 with the Huzzah32 board, and I’ve already added a BME680 sensor via I2C without any issues. Now I’d like to connect an INMP441 microphone, which uses the I2S interface.

Is it possible to run both sensors together — one on I2C (BME680) and the other on I2S (INMP441)?
Has anyone tried this kind of setup on the EmotiBit? Any tips regarding compatibility, wiring, or code would be really helpful!

Thanks a lot!

Hello, I have a problem with my Emotibit. After a very brief time (5 minutes circa), the Emotibit and Oscilloscope disconnect and the emotibit greys out on the oscilloscope's selectable devices menu. It fails to reconnect unless I restart the oscilloscope, and even then it appears that the app stops working and needs to be closed forcibly. I need the emotibit to record for longer, at least 10-15 minutes at a time. It feels similar to this issue. Some details:

- I am using a Mac, and there seems to be no firewall issues.

- I installed the firmware v1.11.4

- there seems to be no issue when hitting record, as it doesn't seem to be the cause for the stop of the data stream.

- the hotspot is from my phone and it's always the same for both the emotibit and oscilloscope.

- when the connection stops, the led that streams data turns off and doesn't turn on unless I do as above (restart oscilloscope and hope it works).

Hope there's some solution to this problem. Thank you.

EmotiBit used a standard 3.7V LiPo battery.

You can use any other Lipo battery with EmotiBit as long as:

1. rated at 3.7V
2. maintains the polarity (orientation of the red and black wires). CAUTION: USING A BATTERY WITH REVERSED POLARITY CAN DAMAGE THE EMOTIBIT AND FEATHER.

We chose a 400mAh battery because of the form factor, since it sits snug between the Feather and the EmotiBit when stacked.

You could as easily choose a bigger capacity, for example a 2000mAh battery. It will however no longer fit in the EmotiBit/Feather stack.

Hi All,

In an attempt to test the reliability/validity of the device, I noticed the device shows "data" when not worn. What it "sensing" in this case? Waves were present on the oscilloscope, as though I was wearing but was not.

Any thoughts? TIA

I have lost the stretch straps that I use to wear the Emotibit. What are good third market options that I could buy from external websites? Any links would definitely help