13931401421

IOT is growing rapidly and we are not far from days where our machines can interact with each other and act accordingly. In fact we will be left behind if we don’t adapt or learn this amazing technology. Here is a list of 10 best IOT hardware platforms which will help us to learn and prototype IOT devices and stuffs.

This list was compiled after seeking experts opinions, conducting polls, forum discussions and much more. Therefore it reflects the choice of many Embedded Programmers and designers. I believe this list will help to choose the perfect platform for  you.

1) Arduino Yun:

Arduino Yun is a hybrid board which has inbuilt Ethernet and Wi-Fi connectivity features. This board is powered by ATmega32u4 which handles USB communication whereas the powerful Atheros AR9331 which handles the Wifi and Ethernet interfaces and comes with a Linux distribution based on OpenWrt. There is no need to add external shileds and interfaces for providing internet connectivity. Also you will get tons of technical support from its huge community. This makes Arduino Yun a great platform for developing IOT projects.

Buy Arduino Yun from Amazon here.

2)Raspberry Pi:

Raspberry Pi is a credit card sized computing platform which runs on linux platform. This board features USB ports for keyboard and mouse, a HDMI port for display and an Ethernet port for wired internet connectivity. However for wireless connectivity we need to go for Wifi adapters which we can get it from the market without any trouble. The vast community makes it perfect to develop IOT projects since we get plenty of hands when we stumble.

Buy Raspberry Pi 2 from Amazon

3)ESP8266:

ESP8266 is a Wi-Fi module that is capable of providing internet connectivity to any microcontroller through UART communication. Also it comes with an integrated TCP/IP protocol stack. Each of these module comes pre programmed with AT commands making it easy to plug and play for IOT projects. This module also can also be used for specific application devices and sensors by using its GPIO pins.

4)Beaglebone Black:

Beaglebone Black is a pretty famous low-cost development platform built around ARM Cortex A8 processor. It runs on Linux environment just like the Raspberry Pi. This board has in-built Ethernet Connectivity feature along with HDMI port to connect a monitor to work on. The robust community of Beaglebone makes it outstanding and viable solution to learn and built IOT projects.

Buy Beaglebone Black Rev C from Amazon.

5) Particle.io (Photon and Electron) :

Particle.io (formerly known as Spark Core) Photon and Electron is a Wi-Fi enabled IOT hardware platform. It was built using powerful STM32 ARM Cortex M3 and Broadcom Wi-Fi chip . The striking feature of this Particle products is a website cloud platform that allows user to send and receive data seamlessly from anywhere rather than only accessing data from your local network.

6) Intel Edison:

Intel Edison is a tiny development platform  featuring a Intel Atom CPU and 32 bit Intel Quark microcontroller. This tiny board carries all Wi-Fi and bluetooth modules for connectivity and thus requires no external modules to do so. Also it carries other striking features such as UART, SPI, I2C, I2S, GPIO and SD card support.

7) Arduino + Shields:

Arduino is pretty familiar in the world of prototyping however only some boards have inbuilt internet connectivity. Meanwhile while other Arduino boards can be used with a external shields to provide the connectivity. You can use Ethernet shield for wired connections and Wi-Fi shield for Wireless connection to the internet. Arduino is significant tool in IOT development because of its robust community.

8) Netduino:

Netduino is an open source electronics prototyping platform build around STMicro STM32F4 controller and runs in .NET Micro Framework. Special versions of this Netduino Ethernet and Wi-Fi certainly gives an edge for IOT developers and enthusiasts. Ethernet board equipped with inbuilt Ethernet connectivity and Wi-Fi connectivity for the Wi-Fi board. Other features such as UART, I2C, SPI and SD card connectivity adds flavor to it.

9) Flutter:

Flutter is a basic radio board powered by SMART SAM3S Cortex-M3 processor provides a range of about half a mile. This board lets users to develop mesh networking protocols and connect devices with least power expense. It is also equipped with ATSHA204 crypto engine to keep the data transmission safe.

10) Tessel 2:

Tessel 2 is an affordable yet robust IOT hardware platform powered by Atmel SMART SAMD21 Cortex M0+ processor  to control IO and Mediatek MT7260n Wi-Fi Router SOC to take care of the connectivity. The board is equipped with built-in WI-Fi , Ethernet port, USB port and runs real Node.js/io.js.

And that’s the end of 10 best IOT hardware platforms to learn and prototype devices. I hope this list might have given some idea about the platforms. However do remember there are plenty of hardware platforms available in the market and this article only listed out handful, famous and most preferred by users. So do make research on it and make sure the platform meets your needs. All the best and happy building.

1. What is RecyclerView?

Google’s upcoming operating system named Android L looks very promising. It is highly focused on rich user experience and what they called it as material design. In this example we will take a look at the new UI widget called RecyclerView.

RecyclerView is more advanced and flexible and efficient version of ListView. RecyclerView ViewGroup is an container for larger data set of views that can be recycled and scrolled very efficiently. RecyclerView can be used for larger datasets to be rendered on the UI like a list. RecyclerView provides maximum flexibility to design different kind of views

2. RecyclerView Example

The tutorial, download the feed data from server, parse the JSON feed response and display the items on list. This example using both RecyclerView and CardView for creating the UI as shown in the following video.

To accomplish this result as shown in the above video, we need to follow the following steps:

1. Create a new Android application in Android Studio IDE and add the support library dependency.
2. Declare an layout for your activity and add a RecyclerView and ProgressBar widget
3. Create an activity class to initiate data download, initialize the adapter and display data on RecyclerView
4. Create RecyclerView row layout. Here we will use the CardView widget.
5. Create an custom adapter that will be used for RecyclerView
6. Implementing RecyclerView click event handling

2.1. Adding Support Library

Android SDK doesn’t includes the RecyclerView class, and hence for using RecyclerView in your project you first need to add the recycler view support library to your project. Android Studio users can add the following graddle dependency to project build.graddle file.

dependencies {
       compile 'com.android.support:recyclerview-v7:+'
       compile 'com.android.support:cardview-v7:21.0.+'
       compile project(':picasso-2.3.4')
}

Notice that in the above dependency declaration, I have added the RecyclerView and CardView support library, and the Picasso.jar. Before this, you need to add Picasso jar module by going to your Android Studio Project properties.

2.2. Adding Internet Permission

You might be aware that, Android application must declare all the permissions that are required for application. As we need to download the data form server, we need to add the INTERNET permission. Add the following line toAndroidManifest.xml file.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.javatechig.app">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
       .....
    </application>
</manifest>

2.3. Declaring Activity Layout

Our first step towards this example is to declare the activity layout. Here in this example, we will add a RecyclerView and ProgressBar inside aRelativeLayout. The progress bar will be shown to user while the data is being downloaded. Add the following code snippets tolayout/activity_feed_list.xml file.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="@dimen/activity_vertical_margin">

    <view
        android:id="@+id/recycler_view"
        class="android.support.v7.widget.RecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerInParent="true" />

    <ProgressBar
        android:id="@+id/progress_bar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true" />
</RelativeLayout>

2.4. Activity Using RecyclerView

RecyclerView is a ViewGroup similar to ListView or GridView. A ViewGroup is an UI widget that is used to render collection of data. In this example, we are trying to download the latest feeds from this site and display it on RecyclerView.  The focus of this tutorial is narrow down to RecyclerView, hence it doesn’t include any explanation for download and parse data from server. For learning how to download data from server, you may read Android Networking Tutorial.

As the data is downloaded, inside onPostExecute() we are initializing the adapter and setting adapter to RecyclerView instance by just calling setAdapter()method.

package com.javatechig.app;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

public class FeedListActivity extends AppCompatActivity {
    private static final String TAG = "RecyclerViewExample";
    private List<FeedItem> feedsList;
    private RecyclerView mRecyclerView;
    private MyRecyclerAdapter adapter;
    private ProgressBar progressBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_feeds_list);

        // Initialize recycler view
        mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        progressBar = (ProgressBar) findViewById(R.id.progress_bar);
        progressBar.setVisibility(View.VISIBLE);

        // Downloading data from below url
        final String url = "http://javatechig.com/?json=get_recent_posts&count=45";
        new AsyncHttpTask().execute(url);
    }

    public class AsyncHttpTask extends AsyncTask<String, Void, Integer> {

        @Override
        protected void onPreExecute() {
            setProgressBarIndeterminateVisibility(true);
        }

        @Override
        protected Integer doInBackground(String... params) {
            Integer result = 0;
            HttpURLConnection urlConnection;
            try {
                URL url = new URL(params[0]);
                urlConnection = (HttpURLConnection) url.openConnection();
                int statusCode = urlConnection.getResponseCode();

                // 200 represents HTTP OK
                if (statusCode == 200) {
                    BufferedReader r = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                    StringBuilder response = new StringBuilder();
                    String line;
                    while ((line = r.readLine()) != null) {
                        response.append(line);
                    }
                    parseResult(response.toString());
                    result = 1; // Successful
                } else {
                    result = 0; //"Failed to fetch data!";
                }
            } catch (Exception e) {
                Log.d(TAG, e.getLocalizedMessage());
            }
            return result; //"Failed to fetch data!";
        }

        @Override
        protected void onPostExecute(Integer result) {
            // Download complete. Let us update UI
            progressBar.setVisibility(View.GONE);

            if (result == 1) {
                adapter = new MyRecyclerAdapter(FeedListActivity.this, feedsList);
                mRecyclerView.setAdapter(adapter);
            } else {
                Toast.makeText(FeedListActivity.this, "Failed to fetch data!", Toast.LENGTH_SHORT).show();
            }
        }
    }

    private void parseResult(String result) {
        try {
            JSONObject response = new JSONObject(result);
            JSONArray posts = response.optJSONArray("posts");
            feedsList = new ArrayList<>();

            for (int i = 0; i < posts.length(); i++) {
                JSONObject post = posts.optJSONObject(i);
                FeedItem item = new FeedItem();
                item.setTitle(post.optString("title"));
                item.setThumbnail(post.optString("thumbnail"));

                feedsList.add(item);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}

Notice that in the above code snippet, we are using the FeedItem POJO class to parse the data from server. Create a new file named FeedItem.java class in your project source folder and add the following snippets.

package com.javatechig.recyclerview;

public class FeedItem {
    private String title;
    private String thumbnail;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getThumbnail() {
        return thumbnail;
    }

    public void setThumbnail(String thumbnail) {
        this.thumbnail = thumbnail;
    }
}

2.5. Creating RecyclerView Adapter

Android RecyclerView includes special kind of adapter which works pretty much same as traditional Android adapters but with additional functionalities. The additional functionalities includes;

• It adds two new methods like onCreateViewHolder() andonBindViewHolder() to organize the code. You must override these two methods for inflate the view and to bind data to the view
• Implements a ViewHolder by default. ConceptuallyRecyclerView.ViewHolder works same as the ViewHolder design pattern which we have been using with other Adapters
• Takes care of the overhead of recycling and gives better performance and scrolling

package com.javatechig.app;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.squareup.picasso.Picasso;
import java.util.List;

public class MyRecyclerAdapter extends RecyclerView.Adapter<MyRecyclerAdapter.CustomViewHolder> {
    private List<FeedItem> feedItemList;
    private Context mContext;

    public MyRecyclerAdapter(Context context, List<FeedItem> feedItemList) {
        this.feedItemList = feedItemList;
        this.mContext = context;
    }

    @Override
    public CustomViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.list_row, null);

        CustomViewHolder viewHolder = new CustomViewHolder(view);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(CustomViewHolder customViewHolder, int i) {
        FeedItem feedItem = feedItemList.get(i);

        //Download image using picasso library
        Picasso.with(mContext).load(feedItem.getThumbnail())
                .error(R.drawable.placeholder)
                .placeholder(R.drawable.placeholder)
                .into(customViewHolder.imageView);

        //Setting text view title
        customViewHolder.textView.setText(Html.fromHtml(feedItem.getTitle()));
    }

    @Override
    public int getItemCount() {
        return (null != feedItemList ? feedItemList.size() : 0);
    }
}

2.6. RecyclerView Row Layout

The above code mentions about another new layout list_row.xml. This is defies the layout for RecyclerView item.  Here in this example, we are using the CardView as parent layout and CardView hosts a RelativeLayout with an ImageView and TextView.

Click here to learn more about Android CardView.

<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:cardview="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="80dp"
    android:layout_margin="8dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="80dp">

        <ImageView
            android:id="@+id/thumbnail"
            android:layout_width="100dp"
            android:layout_height="80dp"
            android:layout_alignParentLeft="true"
            android:layout_centerVertical="true"
            android:scaleType="centerCrop"
            android:src="@drawable/placeholder" />

        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:layout_toRightOf="@+id/thumbnail"
            android:maxLines="3"
            android:padding="8dp"
            android:text="dafdafda"
            android:textColor="#222"
            android:textSize="15dp" />

    </RelativeLayout>
</android.support.v7.widget.CardView>

2.6. Implementing ViewHolder Pattern

Now let us create our ViewHolder class. The ViewHolder contains the reference to the each of the ui widget on the row. We have defined this class as a private class inside MyRecyclerAdapter.

public class CustomViewHolder extends RecyclerView.ViewHolder {
        protected ImageView imageView;
        protected TextView textView;

        public CustomViewHolder(View view) {
            super(view);
            this.imageView = (ImageView) view.findViewById(R.id.thumbnail);
            this.textView = (TextView) view.findViewById(R.id.title);
        }
    }

3. Handle RecyclerView Click Event

Handling click event on RecyclerView is not as sweet as handling click listener in ListView or GridView. Android RecyclerView doesn’t provide any built in listeners or handy way of handling click events.

However we can use workaround to handle click event explicitly by adding the following code in onBindViewHolder() method.

//Handle click event on both title and image click
customViewHolder.textView.setOnClickListener(clickListener);
customViewHolder.imageView.setOnClickListener(clickListener);

customViewHolder.textView.setTag(customViewHolder);
customViewHolder.imageView.setTag(customViewHolder);

Add declare the clickListener variable as follows

View.OnClickListener clickListener = new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        CustomViewHolder holder = (CustomViewHolder) view.getTag();
        int position = holder.getPosition();

        FeedItem feedItem = feedItemList.get(position);
        Toast.makeText(mContext, feedItem.getTitle(), Toast.LENGTH_SHORT).show();
    }
};

4. Download Source Code

Download from GitHub.

Description

LoNet 808 is a mini board based on the latest SIM808 module, it offers 2G GSM and GPRS data along with GPS technology for satellite navigation. Also supports assisted-GPS (A-GPS) for indoor localisation.

The board features ultra-low power consumption, working current is low to 1mA when in sleep mode. That gives your the project incredibly long standby times. It uses a serial port communication, supports common 3GPP TS 27.007, 27.005 and SIMCOM enhanced AT commands.  Integrated with battery charging circuit, it is powered by 3.7V Lipo battery and can be charged by 5V micro-USB directly.

It comes with a mini GPS and GSM antenna, however a external Lipo battery is required.

Features

• Quad-band 850/900/1800/1900MHz
• GPRS multi-slot class12 connectivity: max. 85.6kbps(down-load/up-load)
• GPRS mobile station class B
• Controlled by AT Command (3GPP TS 27.007, 27.005 and SIMCOM enhanced AT Commands)
• Supports charging control for Li-Ion battery
• Supports Real Time Clock
• Supply voltage range 3.4V ~ 4.4V
• Integrated GPS/CNSS and supports A-GPS
• Supports 3.0V to 5.0V logic level
• Low power consumption, 1mA in sleep mode
• Supports GPS NMEA protocol
• Compact size 27mm x 46mm x 10mm
• Standard SIM Card

GPS  Features

• Receiver channels: 22 tracking / 66 acquisition
• Coarse/Acquisition code: GPS L1
• Tracking sensitivity: -165dBm
• Cold start time: 30s (typ.)
• Hot start time: 1s (typ.)
• Warm start time: 28s (typ.)
• Horizontal position accuracy: < 2.5m CEP
• Power consumption – Acquisition: 42mA
• Power consumption – Continuous tracking: 24mA
• Update rate: 5Hz

Related Products

• Li-ion Battery for power supply (http://www.seeedstudio.com/depot/Polymer-Lithium-Ion-Battery-2200mAh-37V-p-1709.html?cPath=1_3)
• DC/DC Voltage Regulator (http://www.seeedstudio.com/depot/Adjustable-DCDC-Power-Converter-125V-35V3A-p-1534.html?cPath=1_4)
• MicroUSB Cable (http://www.seeedstudio.com/depot/USB-To-Uart-5V3V3-p-1832.html)
• USB to UART Tool (http://www.seeedstudio.com/depot/USB-To-Uart-5V3V3-p-1832.html)
• Solder Panel (http://www.seeedstudio.com/depot/3W-Solar-Panel-138X160-p-954.html?cPath=1_118)

Hardware Interface

1. Power Button – this is the hard power switch for the module. When the module is power up, you can turn on or turn off the module by pressing the button for 2s.
2. Li-ion Battery – this is power supply for the module, input voltage is from 3.4V to 4.4V. It uses the JST-2.0mm connector, that make it convenient to connect to 3.7V Li-Po Battery.
3. MicroUSB – the charging interface for Li-Ion battery, of input voltage range from 5V to 7V.
4. GSM Antenna – this is an uFL GSM antenna connector, just connect it to a GSM antenna for receiving GSM signal.
5. GPS Antenna – this is an uFL GPS antenna connector. You can connect either passive or active GPS antenna to it. Active GPS antenna runs at 2.8V voltage.
6. Net Indicator – Red LED, it will tell the what status is about the module linking to network.
7. Status Indicator – Green LED, it will tell whether the module is on, light when the module is running.
8. Breakout Pin – see Pin Definitions for more details.
9. SIM – Card Holder – SIM card holder for standard SIM card
10. Power Supply Pin – used for power soldering and testing.

Pin Definitions

Pin Description

• PWR – this is soft power switch for the module, you can pull it to high level for at least 2s to power up or power down the module.
• RI – this pin will tell you whether the module is on and is there any calls and messages received. It will be pulled to high level when the module is on. And it will change to low for 120ms when a call or message is received.
• RST – this is reset pin for the module. By default it has a high pull-up. If you absolutely got the module in a bad space, you can pull it to low level for 100ms to perform a hard reset.
• RXD / TXD – Serial port, the module uses it to send and receive commands and data. TXD is output, and RXD is input. They can be connected to the 3.3V and 5V level.
• VIO – this is the reference logic level for serial port of the module, the input voltage depends on the logical level of the miccontroller you use. If you use a 5V miccontroller like Arduino, you should have it be 5V, and a 3V logic miccontroller you should set it to 3V.
• BAT – this pin is connected to Li-Ion battery pin, if you want to use only one Li-Ion battery as your power supply, you can use it to drive you microcontroller.
• DTR – this is wake up pin for module in sleep mode. By default it has a high pull-up, and you can set the module into sleep mode by AT command “AT+CSCLK=1”. In the meantime, the serial port will be disabled. To wake up the module and enable serial port, you can pull this pin to low level for about 50ms.

Indicator LEDs

Reference Circuit

Connect to Microcontroller

Connect to PC

Testing AT Command with Arduino

// this sketch is used for testing LoNet with Arduino

// Connect VIO to +5V
// Connect GND to Ground
// Connect RX (data into SIM800L) to Digital 11
// Connect TX (data out from SIM800L) to Digital 10

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

void setup()
{
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  mySerial.begin(9600);

}

void loop() // run over and over
{
  if (mySerial.available())
    Serial.write(mySerial.read());

  if (Serial.available())
  {
    while(Serial.available())
    {
      mySerial.write(Serial.read());
    }
    mySerial.println();
  }
}

Set Baud and Enable Charging Function

It is recommended to execute this process when first time to use the module. In the Serial Monitor columns of tables, input of AT commands are in back, module returns values are in orange.

Get location with GPS

Downloads

• LoNet_808_Schematic.pdf
• SIM800_ATCommand_Manual_V1.02.pdf
• SIM808_Hardware_Design_V1.00.pdf
• SIM808_GPS_Application_Note_V1.00.pdf
• Design file in Eagle Format

Related Resources

• GPRS_Shield library on gitHub
• Adafruit_FONA_Library

Support

Any question, document mistakes and suggestions , please contact deray@deegou.com.

We are not good at programming,  for basis questions we will try to help. But for complex problem, we may not be able to help.

To the end, thank you for your reading.

Today we’ll take a closer look into the world of app development with React Native and Meteor.

Introducing “Friends”

“Friends” is a sample application which is available on GitHub and uses React Native in combination with Meteor to show you a list of friends which is reactive and updates automatically when friends are added, updated or removed.

How is this done?

I recommend you to take a look at the commits on GitHub where I’ve explained how to develop this application step by step.

Additionally here’s a rough explanation what these application do and how they interact with each other:

A basic Meteor application acts as a server and data store for your list of friends.
Some example friends are inserted when the Meteor application is started. A publication makes it possible for other clients to subscribe to a list of friends via DDP.

The React Native app subscribes to the friends publication through DDP and renders the friends on a ListView.

Why React Native?

React Native is a very young, but also promising technology. The main selling point of React Native is the JavaScript approach which makes it easy for you to develop Android and iOS application with the help of pure JavaScript. As a Meteor developer you don’t have to switch between JavaScript and Objective-C / Swift anymore. I’ve you’re experienced with React components it will be even easier as React Native uses React components as a view layer.

Conclusion

Meteor and React Native is a great fit. If you want to develop reactive apps in one language you should definitely give it a try and tinker around. It’s impressive how easy you can develop iOS or Android applications if you have a basic understanding of React!

Github link: https://github.com/openhardwarecoza/Rpi-Zero-USB-Hub

In line with my other projects I need to make a USB hub attachment for the Pi Zero.
Seeing as the community figured out that the Raspberry Pi Design team was clever enough to leave us D+  and D- test points at the bottom, I came up with this design above.

See those pads for D+, D-, gnd and 5v?  Yip, the ide is that you can acually reflow this board onto the back of a Pi Zero!

Where’s the Gerbers?  I haven’t uploaded the gerbers to Github yet, since I only finished the Eagle drawing a few mins ago. Eagles are off to DirtyPCBs.com, and once I tested the board, I’ll upload.

This is a 4 Port USB2.0 hub designed around the TI TUSB2046B

• Directly solderable to Pi Zero USB+PWR pads
• Cutout for GPIO pin bottoms
• Screw holes match Pi Zero

BOM:

Part     Value           Package

C2       0.01uF          C0603
C5       15pf            C0603
C6       15pF            C0603
C7       1uF             A/3216-18W
C9       22Pf            C0603
C10      22Pf            C0603
C11      22Pf            C0603
C12      22Pf            C0603
C13      22Pf            C0603
C14      22Pf            C0603
C15      1UF             A/3216-18W
C16      1uF             C/6032-28R
C32      22Pf            C0603
C33      22Pf            C0603
IC5      LD117AS33TR     SOT223
JP1      USB-JST-2MM-SMT S4B-PH
JP3      USB-JST-2MM-SMT S4B-PH
JP5      USB-JST-2MM-SMT S4B-PH
JP8      USB-JST-2MM-SMT S4B-PH
Q2       12MHz           CTS406
R1       15K             R0603
R2       15K             R0603
R3       10k             R0603
R4       22              R0603
R7       22              R0603
R12      15K             R0603
R13      15K             R0603
R14      15K             R0603
R15      15K             R0603
R16      15K             R0603
R17      15K             R0603
R18      15k             R0603
U$5      TUSB2046B     LQFP-32

As always, design’s yours to do as you please, if you do end up getting rich selling these, remember you owe me a few beers (;

If you like the work I do, please consider supporting me by donating to https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=45DXEXK9LJSWU

Hackaday.io user [Abderraouf] has written an implementation of the new(ish) Spritz cipher and hash for Arduino. While we’re not big enough crypto-nerds to assess the security of the code, it looks like it’s going to be pretty handy.

Spritz itself is a neat cipher. Instead of taking in fixed blocks of data and operating on them, it allows you to process it in (almost) whatever chunks it comes in naturally, and then extract out the encrypted results piecewise. It works both as a two-way cipher and as a one-way hash function. It looks like Spritz is a one-stop-shop for all of your encryption needs, and now you can run it on your Arduino.

In case you are afraid of new implementations of new ciphers (and you should be), Spritz’s pedigree should help to put you at ease: it was developed by [Ron Rivest] to be a successor to his RC4 algorithm, and it incorporates a lot of the lessons learned about that algorithm over the past. This doesn’t exclude subtle flaws in the implementation of the library (no offence, [Abderraouf]!) or your work downstream, but at least the underlying algorithm seems to be the real deal.

[Abderraouf] links it in his writeup, but just for completeness, here’s the Spritz paper (PDF). What crypto libraries do you currently use for Arduino or microcontroller projects? We’ve been fans of XXTEA for ages, but more because it’s simple and small than because it’s secure. Spritz may be simple enough to implement easily, and still more secure. Sweet.