upsidedownlabs / bioamp-exg-pill Goto Github PK

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The ClawController aims to drive the servo between 90 and 180 degrees but

• the code only uses map and does not use constrain to guarantee the values are within that range
• the code has overflow issues with 16bit arithmetic (Arduino Uno int is 16bit) on a large buffer of ADC values

Another improvement is to use float for the envelop function/variable to avoid the coarse conversion for integer based Arduino map.

Hi
I see the TO DO list mentions.. "HeartRate => Heart rate calculation with ECG."
I can contribute on this .
let me know if this is fine with you.

thanks
PS: In case you already have sample dump files/dataset for Heart rate data.. that should be helpful. Otherwise..
we build our own data using the EXG pill.

Many of the samples are using a 128 sample buffer at 500sps. This does not equate to an exact number of mains electricity cycles. A small alteration to 150 equates to 15 cycles at 60Hz or 18 cycles at 50Hz. Empirically this reduces oscillations from the IIR filtering.

First, thanks for providing such a great open source project.
I could not find the value for the gain resistor RG.
How to calculate the gain?
Thanks

Maybe someone will find it useful. I replaced the expensive connector with tin. Such a layout can be printed and sent free of charge under the promotion https://www.allpcb.com/activity/free-pcb-prototype-2021.html

export_gbr2.zip

Like the title says the gerber link in the README seems to be out of date and doesn't lead to a valid page.

I am currently looking into building a few boards using the latest design in the repository but noticed that no wattage was specified for the resistors, alongside a lack of voltage ratings for the capacitors. Do these matter for signal accuracy or can any components (regardless of their capacitor voltage rating or resistor tolerance/wattage) be used?

looks like some misprint

What is the cut-off frequency of the bandpass filter?

Hi, it is this pill can be adapted to be use with a ESP32?

I plan to add some specific features for the relatively new Arduino UNO R4 WiFi board.

1. Use the 12x8 display as a bar chart similar to how the one works on BBC micro:bit in MakeCode.

Other changes not specific to UNO R4 WiFi

1. Improve mains interference rejections by tweaking buffer size. (Also covered by #41)

For example in electromyography.md the first image has a URL of https://github.com/upsidedownlabs/BioAmp-EXG-Pill/blob/main/docs/%20images/EMG/bioamp-exg-pill-emg-wave.jpg which has a space (%20) in front of the images directory, without this space the URL would be correct.

Chris

Hi,
there are not gerber files. Do you plan to publish your latest gerber files ?

Thank you

I took up the task of simulating the EXG pill in LTspice, and this issue thread will be updated as I make progress.
For now, I have tested the low-pass filter section, albeit with ideal components, with the following results.

The -3dB points are at 0.25Hz and 50Hz.
Further simulation will focus on using the correct part model, and simulating the instrumentation amplifier part of the circuit. One important thing to note is that the selected part, the TL074, has an input common mode limitation, the inputs must be at least 2V (or ideally 4V) above the negative rail.

Hey, thanks for providing such a great open source project. But just for your kind information the blink detection code is broken. : )

Do you have expirience or working with TOF protocol?

For any device with LEDs that can show a bar graph it could be useful to provide a crude interference meter to indicate the suitability of that location for ExG measurement.

Hi
First of all., please accept my compliments for this excellent project.

I ran a few simulations for EXG pill schematic. I discovered that the output ranges from 2v to 3v. .. yeah it's not rail to rail..
Feeding this output directly to Arduino (10 bit ADC) , can lead to quite a few bits going unused .

As a solution, may be .., we can add a differential ADC directly onto EXG Pill board.
I have MCP3301 and ATtuy85 in mind.
Cost wise both look similar., though I would personally prefer MCP3301 over ATTiny , because it offer extra 12bit accuracy.
your thoughts?

Hi folks,
is possible to use BopAmp for bioimpecence analysis?

Thanks,
D.