Unable to resolve module `fs` from [Location]: Module does not exist in the module map

[bitabs]

I'm trying to use OpenBCI Cyton in react native application. However the issue is that I can't import it in react native. Is there a way to use Cyton in react native?

This is the error I get:

Loading dependency graph, done.
error: bundling failed: Error: Unable to resolve module `fs` from `C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\serialport\lib\serialport.js`: Module does not exist in the module map

and I try to use it like so:

import Cyton from 'openbci-cyton';

  const ourBoard = new Cyton();
  ourBoard.connect("COM3").then(() => {
    ourBoard.on('ready', () => {
      ourBoard.streamStart();
      ourBoard.on('sample', (sample) => {
        for(let i = 0; i < ourBoard.numberOfChannels(); i++) {
          console.log(
            "Channel" + (i + 1) + ": " + sample.channelData[i].toFixed(8) + " Volts."
          );
        }
      });
    });
  });

[andrewjaykeller]

Could this openbci-rx help?

[andrewjaykeller]

Does node seriaport support react native?

[bitabs]

@aj-ptw aparently RN doesn't support serialport

[andrewjaykeller]

Checkout electron, or the openbci_hub

[bitabs]

Are you suggesting to use electron with react native? I have already played with Openbci_hub but only on web-based. However, my target is actually mobile. @aj-ptw

[andrewjaykeller]

Ah perhaps look into the WiFi shield which would run on react native.

[bitabs]

Ah damn, I have only ordered Cyton to work with. Is there really no other alternative to make it work using Cyton? @aj-ptw

[baffo32]

@NaseebullahSafi It should be possible to use rn-nodeify and a replacement module such as react-native-usbserial to do this, but you would be treading new ground attempting it, and would likely run into hitches that might need you to look inside things and develop your own workarounds.

[bitabs]

Ok Thanks to @baffo32 and @aj-ptw I'm finally able to use the node module OpenBCI in react native. But the issue still remains; in that when OpenBCI module is imported:

const Cyton = require('openbci-cyton');

We get "Maximum call stack size exceeded" error and so I presume that OpenBCI has a node event loop for I/O operations.

Is there anyway way we can fix this?

RangeError: C:/King's_College_London/Final_Year_Project/HeartFailure/node_modules/openbci-cyton/openBCICyton.js: Maximum call stack size exceeded
    at validate (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-types\lib\definitions\index.js:85:20)
    at validator (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-types\lib\definitions\index.js:57:7)
    at Object.validate (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-types\lib\definitions\index.js:190:10)
    at validate (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-types\lib\index.js:505:9)
    at Object.builder (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-types\lib\index.js:466:7)
    at PluginPass.CallExpression (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-plugin-rewrite-require\index.js:85:15)
    at newFn (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-traverse\lib\visitors.js:276:21)
    at NodePath._call (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-traverse\lib\path\context.js:76:18)
    at NodePath.call (C:\King's_College_London\Final_Year_Project\HeartFailure\node_modules\babel-traverse\lib\path\context.js:48:17)

[xloem]

I don't know how to solve that issue, but just to add resources another alternative is the nodejs-mobile project, which takes the opposite approach of providing a full node runtime on mobile as a background process. No clue if anybody's tried to make serial work with it.

[bitabs]

@xloem ok thanks. I'm just about to create a new project for testing with node-js in react native and try to make it work. I'll update you guys. But remember guys, this is a very serious limitation to OpenBCI-Cyton because many people are planning to create mobile apps for cyton rather than a web-based primarily because of portability or whatnot.

[bitabs]

@xloem I had a very long chat with the author of that project and although we were able to initialise openbci module in react, we were not able to use the serialport of nodejs.

@aj-ptw I would really appreciate if you could enlighten me. Is there any approach for simply connecting openbci to react native apart from nodejs?

[andrewjaykeller]

If you want to start developing today, buy the WiFi Shield. You could already be streaming data! The OpenBCI Cyton is in need of a physical hardware update before streaming to a mobile phone.

[bitabs]

Apologies if I have misunderstood you. But shouldn't it be possible for streaming data from the cyton to react native as long as the phone is connected to the PC along with the cyton dongle? @aj-ptw

[andrewjaykeller]

I'm sorry I'm not really sure what react native is I guess. Can you explain to me where react native is running