Fun with raspberry pi

Hey Followers! 

Today me and my brother, Aiden, explored the Raspberry Pi and made a video about it!

If you've been following our Google+ and Twitter feeds you know we are getting ready for the WRO Footbal competition.  We've been working with data logging and wanted to share some techniques for other teams that want to use these features in the Labview Mindstorm software.
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Today we are trying to make sure our robot goes to the right goal because it wouldn't be very useful to score goals on ourselves!  To figure this out we needed to discover what the compass values were across the field.

To do this we created an Experiment in the LabView Mindstorm software which sampled the compass sensor values as we moved it across the field.

To learn more about how to create an experiment the following Lego Education video is really helpful:  https://www.youtube.com/watch?v=wP58lVrDA6I

Although Mindstorm provides alot of analysis tools we wanted to look at the data in Microsoft Excel.  To do this we had to export our experiment by doing the following:

Open a new experiment.

• Go to the Tools menu and select Data Log File Manager.
• Browse to the the .rdf file and click the Import button. (It can be on the brick or on your computer.)
• Close the Data Log File Manager
• On the Tools menu, select Export Datasets
• Save the file as a .csv file
• Open the .csv file in Excel

Once we opened the file in Excel we could determine the Min, Max and Standard Deviations for our sensor values.  This helped established what range to use for determining the direction the robot was facing. This is a BIG improvement over having to write these values down by hand which is what I had been doing before!

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Daisy Chaining the EV3

Hello faithful followers!

Today, we decided to try and Daisy Chain our EV3`s. For those of you who don`t know,

Daisy Chaining is a wiring scheme in which multiple devices are wired together in sequence or in a ring. 

This is helpful to us because we can use 16 motors and sensors instead of our regular 4.

The first thing we found was that you needed a USB cable to connect to from one EV3 to the next. Here`s one that was recommended, which seems to be a nice fit... we ended up using some that was laying around the house. what can you do?¯\_(ツ)_/¯

Anyway, we hooked up our four EV3`s togther via USB cable and than proceeded to connect our main one via bluetooth. We quickly found that we had plugged it in the wrong order and it goes USB to PC. After we had gotten that figured out, we had to tell our software that we wanted to daisy chain.

To do that you have to go to the little wrench icon on the left hand of the screen which should look like this;

you should be able to see the words daisy chain mode by a little check box

click it and than voila! you have just enabled daisy chaining!

After that, go back to your program. When you drag an action block onto the canvas, it should look like this;

click on the little 1, and it should let you choose between your bricks! (1 being the main brick the computer is hooked up too, 2 being the one connected to that one and so on.)

Here`s a video of our final product!

Enabling Wifi on the EV3

Today we decided to tackle our first goal of Hacking Our EV3 , enabling the wifi on our ev3. We have a couple of reasons for wanting to connect via WiFi over Bluetooth.

• We want to use Simulink via Mathlab but it does not support Bluetooth.
• We want to replace the Lego Mindstorm OS with the EV3Dev operating system
• We ultimately want to be able to control our EV3 through a tiny Java Web Server called Lejos  so we can control our robot over the web.

The EV3 supports WiFi but not natively, so you have in purchase and install a WiFi dongle that attaches to the USB port on the Mindstorm.  

So how hard can it be to install a WiFi dongle?  The has a limited number of WiFi options, in fact only one WiFi dongle is supported by Lego, the rather cumbersome NETGEAR N150 Wireless Adapter (WNA1100)  .  However, we did some research and found a smaller version which will fit in with the Technic beams more seamlessly.  The WiFi adapter we purchased was the Edimax EW-7811Un 150Mbps 11n Wi-Fi USB Adapter, Nano Size.  You can purchase through Amazon here.  It's less than $10 and comes with free shipping!

We plugged the WiFi dongle into our EV3 and went to settings on the Brick and enabled the wifi option (this is a really good tutorial on how to turn on wifi for the EV3).  We than opened up the software and tried to connect the EV3to the computer.

It turns out it wasn't that simple.  Although we were able to connect the EV3 to our network and successfully assign it an IP Address, we couldn't get the Mindstorm software to recognize our EV3 was accessible via WiFi.

After trying to get the robot to connect 5 times, we still got the same error message so we turned to our good friend Google. It than became apparent that lots of people had the same problem. To troubleshoot the problem we downloaded a program called Wireshark that allows you to see whats happening on your network including how the traffic from the EV3 was going across the  network. We could see that the EV3 was polling every 10 seconds via UDP packets its Serial number on Port 5555.  We then tried to wake our EV3 by sending it a packet via TCP/IP using a different program called packet sender. Packet Sender allows you to send messages to things (like your robot). This helped us understand that the EV3 was on the network and was accessible to receiving packets.  

We turned back to our Mindstorm program, praying to the great gods of lego that we would be able to find a different way to connect to wifi. We connected our robot via USB cord in hopes to that we could connect it to the wifi that way.  After analyzing every single option in the EV3 software we noticed that in tools there was an option called "Wireless setup" we clicked on it and it pulled up this 

We than selected the wifi we wanted to connect to, typed in the password and voila, we were connected to the wifi!

So really the steps are pretty simple, plug in your WiFi Dongle, Connect your EV3 via USB, Select the Wireless setup menu option under Tools in the Mindstorm software and then follow the wizard to connect your Mindstorm to your wireless network!

 

Hacking the EV3

Now that the FLL season is finished for us we`ve decided to explore the ev3 a little bit and whats a better way than hacking it? Here`s a couple goals that we`ve outlined to hack our robot:

Goals:

• Wifi enable Ev3 Brick (for those interested here`s a link to the wifi adapter we used for our robot)
• Enable other programming environments
• Mathlab/simulink
• Robot C 
• Explore attachments/sensors
• video camera
• GPS
• Read Hacking the EV3 by  John Baichta
• Install operating systeams
• connect 2+ EV3 together 
• Connect the EV3 to andruino

We will be keeping our faithful followers updated on our progress and will post tutorials on how we did it and what we learned along the way! 

4H Group of Programming

So, tonight the 4H group of Tomball came together today for a very important meeting. To discuss... our plans for Saturday's  4H Everybody's Gotta Eat competition, at the Houston Livestock Rodeo.

While this is not an FLL Competition Tournament, it still uses the Mindstorm base and structure. Awesome. We've completed two missions.

For this team, Taryn and Laura are the programmers. Aiden and Steven are the engineers. And Sophia and I have been working on Twitter and this Blog. Sophia has learned a lot about Twitter.

Steven and Aiden working hard.

The Missions

Here's a video of our missions!

We've been practicing a lot lately. Tegan and Aiden have been doing a great job, and we're pretty confident.

The competition is tomorrow! :O But I think we're ready for it.

Good luck, other competitors.