How to transfer data in files from different locations to app directory

In Android apps, we might have seen various instances in-app where we can import, export or save files. Now, where does the files go to or come from? There needs to be a specific folder or directory (maybe root) for a particular app which inturn contains the necessary files, the user has worked with from the app. In this blog, we will be learning about the backend of how to create directories and store files in them dynamically with proper content.


I have been working with FOSSASIA on the project Neurolab-Android. In the app, we have various program modes, which has the option to save/record data. The saved data gets logged in a new file in the Neurolab directory/folder. Feel free to go ahead and explore the feature.

The Save/Record feature in Neurolab can be found in the app bar or as an option in the drop down menu present in the app bar itself in any program mode. The feature becomes functional, once the data is imported with the import data feature which is also present in the app bar.

                                              Figure: Demonstration of features in Neurolab


Now, starting off, there are apps out there wherein users can save files from different segments in the app and those saved files can be used by the app itself at other times as they belong to that app itself specifically.

First off, we need to make sure we have a directory for our app, wherein the files will get stored. If the directory or folder is not present, it needs to be created.

File directory = new File(
                Environment.getExternalStorageDirectory().getAbsolutePath() +
                        File.separator + DIRECTORY_NAME);
        if (!directory.exists()) {
            try {
            } catch (Exception e) {

Now, once the directory is present, we can go ahead to keep the saved files in it. Also we will be implementing category-wise storage of the files. Simply put, we will be storing csv files in the CSV folder, xls files in the Excel folder, etc. In the below code example, we see the use case of CSV ‘category’.

private void categoryWise() {File categoryDirectory = new File(
                Environment.getExternalStorageDirectory().getAbsolutePath() +
                        File.separator + DIRECTORY_NAME + File.separator + category);
        if (!categoryDirectory.exists()) {
            try {
            } catch (Exception e) {

For saving a file in our app, we need to get (import) the file into our app. Once the file is imported, we can get the path of the file with the help of its URI. Let’s assign the path to a variable named ‘importedFilePath’. Then we place the imported file in the required category directory within our parent app directory depending and deciding upon the extension of the imported file.

File importedFile = new File(importedFilePath);
        Date currentTime = Calendar.getInstance().getTime();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String fileName = sdf.format(currentTime);
        File dst = new File(Environment.getExternalStorageDirectory().getAbsolutePath() +
                File.separator + DIRECTORY_NAME + File.separator + categoryDirectory + File.separator + fileName + ".$extension");
        if (!dst.exists()) {
            try {                categoryWise()
                transfer(importedFile, dst);
            } catch (IOException e) {

Now, we have the ‘importedFile’ and the destination file path (dst) where the file needs to be stored for our app. The ‘extension’ can be of any type you feel the file should be. Here, for the fileName we are using the current date and time together.

Then, we can come to the function ‘transfer’ which has been called above.

private static void transfer(File src, File dst) throws IOException {
        InputStream in = new FileInputStream(src);
        try {
            OutputStream out = new FileOutputStream(dst);
            try {
                // Transfer bytes from in to out
                byte[] buf = new byte[1024];
                int len;
                while ((len = > 0) {
                    out.write(buf, 0, len);
            } finally {
        } finally {

In the ‘transfer’ function, we initialize an input stream with the source file path and the output stream with the destination file path. We read the content in the form of  a certain chunk of bytes from the source file and write to the output stream (destination file).

Finally, we close the output and input streams simultaneously.

Thus, we have our code ready to be bound by UI actions/buttons. Once, the user interacts with the action in your app, the imported file will get saved in the specific directory of your app.

That’s it. Hope this blog enhanced your Android development and Java skillset. 


  1. Author – Google Android Developers, Article – Data and File storage, Website –
  2. Author – Rakshi and Thomas, Article – How to make a copy of file in android, Source – Stack overflow, Website –

Tags: FOSSASIA. Neurolab, GSOC19, Open-source, File-storage

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Dialog Component in SUSI.AI

Dialog Component in SUSI.AI is rendered in App.js to remove code redundancy. Redux is integrated in the Dialog component which allows us to open/close the dialog from any component by altering the modal states. This implementation allows us to get rid of the need of having dialog component in different components.

Redux Code

There are two actions and reducers which control the dialog component. Default state of isModalOpen is false and modalType is an empty string. To open a dialog modal the action openModal is dispatched, which sets isModalOpen to true and the modalType. To close a dialog modal the action closeModal is dispatched, which sets isModalOpen to default state i.e. false.

import { handleActions } from 'redux-actions';
import actionTypes from '../actionTypes';

const defaultState = {
 modalProps: {
   isModalOpen: false,
   modalType: '',

export default handleActions(
   [actionTypes.UI_OPEN_MODAL](state, { payload }) {
     return {
       modalProps: {
         isModalOpen: true,
   [actionTypes.UI_CLOSE_MODAL](state) {
     return {
       modalProps: defaultState.modalProps,

Shared Dialog Component

Dialog Modal can be opened from any component by dispatching an action. 

To open a Dialog Modal: this.props.actions.openModal({modalType: [modal name]});

To close a Dialog Modal: this.props.actions.closeModal();

Shared Dialog Component has a DialogData object which contains objects with two main properties : Dialog component and Dialog size. Other props can also be passed along with these two properties such as fullScreen. Dialog Content of different Dialogs are present in their respective folders. Each Dialog Content has a Title, Content and Actions.Different Dialog types present are:

  1. Confirm Delete with Input: This dialog modal is used when a user deletes account, device and skill. 
  2. Confirm Dialog: This dialog modal is used where confirmation is required from the user/admin such as on changing skill status, on password reset,etc.
  3. Share Dialog: This dialog modal opens up when the share icon is clicked in the chat.
  4. Standard Action Dialog: This dialog modal opens up on restore skill, delete feedback, system settings and bot.
  5. Tour Dialog: This dialog modal opens up SUSI.AI tour.

To add a new Dialog to DialogSection, the steps are:

  1. Import the Dialog Content Component
  2. Add the Dialog Component to DialogData object in the following manner:
const DialogData = {
[dialog componet name]: { Component : [imported dialog component name], size : [size of the Dialog Component]},

Code (Reduced)

const DialogData = {
  login: { Component: Login, size: 'sm' },
const DialogSection = props => {
 const {
   modalProps: { isModalOpen, modalType, ...otherProps },
 } = props;

 const getDialog = () => {
   if (isModalOpen) {
     return DialogData[modalType];
   return DialogData.noComponent;

 const { size, Component, fullScreen = false } = getDialog();

return (
      open={isModalOpen || !visited}
      onClose={isModalOpen ? actions.closeModal : actions.setVisited}
       {Component ? <Component {...otherProps} /> : null}

In conclusion, having a shared dialog component reduces redundant code and allows to have a similar Dialog UI across the repo. Also having one component managing all the dialogs removes the possibility of  two dialogs being fired up at once.


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My Devices in SUSI.AI

In this blog I’ll be explaining how to view, edit and delete connected devices from SUSI.AI webclient. To connect a device open up the SUSI.AI android app, and fill the details accordingly. Device can also be connected by logging in to your raspberry pi. Once the devices is connected you can edit, delete and access specific features for the device from the web client.

My Devices

All the connected devices can be viewed in My Devices tab in the Dashboard. In this tab all the devices connected to your account are listed in a table along with their locations on the map. Each device table row has three action buttons – view, edit and delete. Clicking on the view button takes to device specific page. Clicking on the edit button makes the fields name and room editable in table row. Clicking on the delete button opens a confirm with input dialog. Device can be deleted by entering the device name and clicking on delete.

To fetch all the device getUserDevices action is dispatched on component mounting which sets the reducer state devices in settings reducer. initialiseDevices function is called after all the devices are fetched from the server. This function creates an array of objects of devices with name, room, macId, latitude, longitude and location.

 componentDidMount() {
   const { accessToken, actions } = this.props;
   if (accessToken) {
       .then(({ payload }) => {
           loading: false,
           emptyText: 'You do not have any devices connected yet!',
       .catch(error => {
           loading: false,
           emptyText: 'Some error occurred while fetching the devices!',
   document.title =
     'My Devices - SUSI.AI - Open Source Artificial Intelligence for Personal  Assistants, Robots, Help Desks and Chatbots';
 initialiseDevices = () => {
   const { devices } = this.props;
   if (devices) {
     let devicesData = [];
     let deviceIds = Object.keys(devices);
     let invalidLocationDevices = 0;
     deviceIds.forEach(eachDevice => {
       const {
         geolocation: { latitude, longitude },
       } = devices[eachDevice];
       let deviceObj = {
         macId: eachDevice,
         deviceName: name,
         location: `${latitude}, ${longitude}`,
       if (
         deviceObj.latitude === 'Latitude not available.' ||
         deviceObj.longitude === 'Longitude not available.'
       ) {
         deviceObj.location = 'Not found';
       } else {
         deviceObj.latitude = parseFloat(latitude);
         deviceObj.longitude = parseFloat(longitude);

Device Page

Clicking on the view icon button in my devices redirects to mydevices/:macId. This page consists of device information in tabular format, local configuration settings and location of the device on the map. User can edit and delete the device from actions present in table. Local configuration settings can be accessed only if the user is logged in the local server.

Edit Device

To edit a device click on the edit icon button in the actions column of the table. The name and room field become editable.On changing the values handleChange function is called which updates the devicesData state. Clicking on the tick icon saves the new details by calling the onDeviceSave function. This function class the addUserDevice api which takes in the new device details.

startEditing = rowIndex => {
   this.setState({ editIdx: rowIndex });
 handleChange = (e, fieldName, rowIndex) => {
   const value =;
   let data = this.state.devicesData;
     devicesData:, index) =>
       index === rowIndex ? { ...row, [fieldName]: value } : row,

 handleDeviceSave = rowIndex => {
     editIdx: -1,
   const deviceData = this.state.devicesData[rowIndex];
   addUserDevice({ ...deviceData })
     .then(payload => {})
     .catch(error => {

Delete Device

To delete a device click on the delete icon button under the actions column in the table. Clicking on the delete device button opens up the confirm with input dialog modal. Type in the name of the device and click on delete. Clicking on delete calls the handeRemoveDevice function which calls the removeUserDevice api which takes in the macId. On deleting the device user is redirected to the My Devices in Dashboard.

 handleRemoveConfirmation = () => {
     modalType: 'deleteDevice',
     name: this.state.devicesData[0].deviceName,
     handleConfirm: this.handleRemoveDevice,
     handleClose: this.props.actions.closeModal,
 handleRemoveDevice = () => {
   const macId = this.macId;
   removeUserDevice({ macId })
     .then(payload => {
     .catch(error => {

In conclusion, My Devices tab in dashboard helps you manage the devices connected with your account along with specific device configuration. Now the users can edit, view and delete their connected devices.


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How to fix undetected Arduino boards in Android

In the development process of the Neurolab Android app, we needed an Arduino-Android connection. This blog explains how to  establish the connection and getting the Arduino board detected in my Android device

Context-connecting the board and getting it detected

Arduino boards are primarily programmed from the Desktop using the Arduino IDE, but they are not limited to the former. Android devices can be used to program the circuit boards using an application named Arduinodroid.

Arduino is basically a platform for building various types of electronic projects and the best part about it is that, it is open-sourced. Arduino, the company has got two products The physical programmable circuit board (often referred to as a microcontroller). 

Examples of Arduino circuit boards – UNO, UNO CH340G, Mega, etc. Find more here.

Connecting the board and getting it detected

Arduino boards are primarily programmed from the Desktop using the Arduino IDE, but they are not limited to the former. Android devices can be used to program the circuit boards using an application named Arduinodroid.

In this blog, we are going to use Arduinodroid app for establishing a connection between the Arduino board and the Android device, getting the board detected in the Android phone and uploading a sketch to it.

Materials/Gadgets required:-

  1. Arduino board (UNO preferably)
  2. Arduino-USB Cable
  3. OTG Cable
  4. Android device

Now, one of the most frequent issues, while establishing a connection and getting the Arduino board detected with the Android device, is the error message of: “No Arduino boards detected” in the Arduinodroid app. There can be a few core reasons for this –

  1. Your Android mobile device isn’t USB-OTG supported – Probably because it is an old model or it might be a company/brand-specific issue.
  2. Disabled OTG Mode – Be sure to enable USB-OTG mode (only if your device has one) from the Developer options in your Android device settings.

Even after trying and making sure of these above points, if you still continue to get an error while uploading a sketch from the Arduinodroid app like this:

                                                            Figure 1: The Error Message

Follow the steps below carefully and simultaneously one after the other:

  1. Look for any external module attached to your Arduino board using jumper wires. If so, remove those connections completely and press the reset button on the Arduino circuit board. The attached modules can be one of the following: Micro SD Card module, Bluetooth module, etc.
  2. Remove pin connections, if any from the TX and RX pin-slots in the Arduino board. These pre-attached pins can cause unnecessary signal transfers which can hinder and make the actual port of Arduino board busy.
  3. Before connecting the Arduino to the Android device, go to the drop down menu in the app at the top-right corner -> Settings -> Board Type -> Arduino -> UNO
  4. Now, you need to code a sketch and make it ready for compile and upload to the circuit board. We will use a basic example sketch for this case. Feel free to try out your own custom coded Arduino sketches. Go to the drop-down menu -> Sketch -> Examples -> Basics -> AnalogReadSignal
  5. Don’t compile the sketch yet because we haven’t connected any Arduino circuit board to our Android device. So first, connect the Arduino circuit board to the Android device through the OTG cable connected to the Arduino-USB cable.
  6. You should see some LEDs lit up on the circuit board (indicates power is flowing to the board). Go ahead to compile the sketch. Click the ‘lightning’ icon on the top in the toolbar of the app. You should see the code/sketch getting compiled. Once done you should see a toast message saying “Compilation finished”. This signifies that your code/sketch has been verified by the compiler.

                                              Figure 2: Successful Compilation of sketch

This process is inevitable and there is hardly any issue while compiling a sketch.

       7. Upload the sketch: Click on the upload icon from the toolbar in the app. Upload             should start once you get a pop-up dialog like this:

                                           Figure 3: Arduino board detected successfully

Once you click Okay, the upload shall start and if your code is correct and matches the particular Arduino circuit board, you shall get a successful upload, which was not the case earlier for the error : “no Arduino boards found” on clicking the upload button.

So, that’s it then. Hope this blog adds value to your development skills and you can continue working bug free with your Android-Arduino connections.


  1. Author – Nick Gamon, Article – Have I bricked my Arduino uno problems with uploading to board, Date – Nov’16 2016, Website –
  2. Author – Arduino Products, Article – Arduino boards, Website –

3. Author – Anton Smirnov, App name – ArduinoDroid, Website –

Tags: FOSSASIA, Neurolab, GSOC19, Open-source, Arduino, Serial terminal

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