Raspberry PI – Network access

Introduction

One of the benefits of having a machine like the RPI is that you can set it up on your home network and access it without having to worry about a keyboard, mouse or monitor.

Combined with the RPIs small size, and the ability to place it in a custom case with a wall mount, these features are what make it one of the most exciting tools for home embedded/smart systems.

The steps below are an introduction on getting your RPI to boot up with ssh access, and allow you to connect to it from another machine on your home network.

SSH

So what is ssh? In brief ssh (secure shell) is a method that allows us to log into other machines over the network, most commonly through a command line tool (for those of you with a Mac you can do this via the Terminal). Once logged in, depending on our permissions we can then perform actions on the machine we are connected to.

For a deeper more complex technical evaluation of ssh you can read the wiki article here.

For the purposes of configuring our RPI (and later using it as a controller) we are going to be setting up ssh access so we can work on the machine remotely.

In my specific case, this is born from the fact that my router is nowhere near my TV set so trying to configure the RPI with a monitor, but without network access is going to be impossible in some cases i.e. installing HTSQL.

Steps to set up 

Fist of all connect your RPI up to its power supply, monitor and keyboard. Then log in.

Raspberry PI login

Raspberry PI login

At this point you may want to set the date of your RPI if you haven’t done so already.

By default the keyboard is set up to be UK format, so the @ is actually the ”

To set the date:

sudo date –set “23 APR 2012 16:01”

Next you will need to set the RPI to start ssh when it boots. To do this follow the next steps:

  1. cd /boot/
  2. sudo cp bootenable_ssh.rc boot.rc

The above copies bootenable_ssh.rc and creates a second version called boot.rc. The boot.rc version is then loaded when you start your RPI up.

Now follow the next steps:

  1. cd /etc/network
  2. vi interfaces

By default vim isn’t installed on the RPI, so if you haven’t taken the step to install it, you’ll need to use vi to edit the interfaces file.

You’ll need to edit the settings in the interfaces file as follows:

  1. Add eth0 to this line: insert eth0 so : auto lo eth0
  2. Change iface eth0 inet dhcp  to  iface th0 inet static
  3. Now add:
    address 192.168.0.202
    netmask 255.255.255.0
    gateway 192.168.0.200

Finally save the file  – press  : then type x and hit enter to save and exit
The above steps have now added configuration to tell the RPI to run on a static IP address on your local network.

Testing the above worked

You can now log out of your RPI and power it down.

Next, boot the PI back up with your network jack attached. Your PI should now boot with ssh enabled.

Raspberry PI hooked up

Raspberry PI hooked up

I plugged my PI directly into my Cisco E4200 router. I then logged into it via 192.168.1.1 in my web browser (type http://192.168.1.2 into the address bar) – note this may be different on your home network depending on how you have configured it.

If you have a Windows machine for example and your router is plugged into that, you can run:

ipconfig

Now look for Default Gateway, this will give you the IP address that the router should be running on.

Once your PI is powered up and booted (you should also see a yellow light, indicating you are on the network) you can shell (ssh) into your server.

Note:

The fixed IP address you assigned may not work. To test if it did try:

 ssh pi@192.168.0.200

If this does not work, log into your router and check the DHCP Client table. Most of the devices I run on my network have a client name e.g. kindle-xxxxxxxxxx.

You may now see a device appear in the list with no name. To confirm which device is your RPI, you can try disconnecting it, refreshing the DHCP client table, reconnecting it and then refreshing again. The new device added to the list is probably your RPI.

Next, take the new IP address from the table and shell into the machine (via Terminal, console, Cygwin or whatever you are using):

ssh pi@

This gave me the authenticity message which I accepted. I then entered the default password for the PI, and presto! I am now logged in.

Conclusion

So I need to investigate how to ensure the static IP is always picked up, I’ll blog a separate post on that for those of you having problems.

For the moment we now have an easy way to get access to the PI without a monitor and can go ahead and install whatever packages we need.

Raspberry PI case printing

Introduction

In my previous post I hd mentioned that having got the 3D printer ready to go again, I planned to print the case for my Raspberry PI. After viewing some of the cases on Thingiverse I located one that had been designed with four wall mounts.

In my initial attempt to export the image to the SD card, everything had seemed to work correctly, however the MakerBot was unable to view it. So during my lunch hour today I removed the file from the SD card and started over.

Exporting the case to SD card

My first step was to load the top portion of the case’s .stl file into ReplicatorG. Using the 3D rendering of the image I was able to align the case top so that it was positioned in the middle of the axis. Once this was complete I then exported the file to Gcode. Finally I edited the Gcode so the heat of the base plate would be 120 degrees F.

I then followed the steps above for the bottom portion of the case.

The images were now ready to export to SD format. Using the option on the menu I exported directly to my SD card, and also shortened the rather long names of the files in case this contributed to the MakerBot not being able to view them.

Ejecting the SD card I was now ready to give printing another try.

Printing the case

Loading the SD card into the MakerBot I could now view the files on the menu and so set the top to print. I left the printer to do its thing and checked back in on it a couple of hours later. As you can see in the picture below, the printing was successful:

Raspberry PI case

Raspberry PI case

Raspberry PI top

Raspberry PI top

Raspberry PI bottom section

Raspberry PI case

With the two pieces of the case complete my next job was to clean the lattice off the objects and try the Raspberry PI out to see if it fit.

Here you can see the case clipped together:

Completed case

Completed case

I would recommend for the next steps having some kind of tray to put the case on, an X-acto knife and some sand-paper or a tool to smooth off the plastic (the later being something I didn’t have at hand at home, so I’ll need a trip to Home Depot).

Most objects are printed onto a lattice base, so your first job will be to remove this.

As you can see below, the lattice that the objects are printed on comes off pretty easily, you can snap this off with your hand right after you take the object out of the MakerBot.

Lattice

Lattice

As a note: One thing I have noticed about the quality of the print – in general – is that the objects made on the MakerBot have a lot of rough portions that need to be cut or smoothed off. This takes a little while so with my RPI case I set some  time aside this evening to work on cleaning it up.

Here you can see the bottom portion of the RPI case:

Case bottom

Case bottom

Outside of the RPI case

Outside of the RPI case

Using an X-acto knife I gently removed the top layer on the case to reveal the better resolution layer below. However this is a tedious process and even with the X-acto knife didn’t give me the result I wanted. It is also messy so having a tray to catch the off-cuts was handy. At this point some sandpaper would have been useful. Since I didn’t have this at home, doing the final sanding off  had to wait. Once I do this I also plan to spray paint the case, which will be the subject of another post.

Having done a best of a job as possible cleaning things up I now tried placing the RPI inside the bottom section. The RPI fitted in here no problem. I now tried to place the top onto the RPI and close the case. At this point I noticed that one of the plastic lips inside the case was catching on the RPI near the SD card port. Taking the X-acto knife I cut this portion off and now the case closed perfectly.

You can see the final result here:

RPI in the case

RPI in the case

So as you can see above, we have our first attempt at a printed Raspberry PI case complete. Once I finish off the aesthetics of the case, I will then be able to attach it to the wall and wire it up to my home network. I still have some configuration to complete on the RPI in the area of HTSQL installation which I will be blogging about soon.

All in all the process has been a great learning experience and given me a number of avenues to investigate, including how to ensure a better resolution and quality of print on future 3D objects.

It’s also been the first project that has been successfully completed on our co-op’s MakerBot leading to us now feeling comfortable with everyone jumping in and printing their own creations.

With regards to cases, for the Arduino thermostat, I plan to design my own housing unit in Blender, which will also be the subject of a future blog posting.

Finally, if anyone has any suggestions of improving the print quality, please feel free to comment below!

Raspberry PI case, soldering irons and other such matters

Introduction

This post will be a round up of what has been happening on the intelligent heating project.

In my last post I detailed how we had encountered a problem printing an object on the MakerBot and how this had resulted in some slight damage to the build plate.

Thankfully the damage wasn’t critical. This week we were able to re-cover the build plate with the film (which is a real awkward task and takes a couple of attempts to get right) and start printing object again!

The picture below shows the MakerBot back in action:

MakerBot

MakerBot

Raspberry PI (RPI) case

Now that the printer is back in action I did some research online for Raspberry PI cases. The thingiverse website has a selection of RPI cases however I found one in particular that matched my requirements, as it came with a mounting bracket for screwing the case to the wall.

Since my RPI will be sitting inside a small closet where our electrical box is located, this seemed perfect.

You can see the case here:

http://www.thingiverse.com/thing:25363

I downloaded the STL files and then loaded them into ReplicatorG. First of all I built the Gcode for the base section of the case, and then exported to flash card format.

I now encountered a small problem, the case wasn’t visible on the flash card via the MakerBot menu. I’m not immediately sure what happened here, so I’ll be trying a fresh export on Monday and will try reloading it. Providing this works, then the first version of the case will be printed next week.

I’ll be photoing and uploading the results to the blog.

Soldering Iron

At the end of the month I plan on ordering some components for the Arduino from Adafruit, this will consist of a temperature sensor and a touch screen for the thermostat. I’ve not settled on which products I’m going with yet, but once this is decided I’ll be adding a post to the Thermostat thread details the specs and costs.

Of course in order to attach the components to the Arduino it helps to have a soldering iron. So today I picked one up from Home Depot. It cost around $15 and some extra electrical solder was around $9:

Soldering Iron

Soldering Iron

and

Solder

Solder

So I am now all set to start connecting up the components for my Arduino thermostat.

Raspberry PI and TV

In my earlier blog I had mentioned my plan to install HTSQL on the RPI. I have still not gotten around to doing this as a result of the equipment I am missing. I will need a cable to connect the video out up to a spare monitor  I have ready. My other option is of course to buy another monitor with a HDMI output on it. However I have had some problems with HDMI jack not working on the RPI so I will need to investigate this further.

Conclusion

So the above details where the project is currently at. Expect further updates over the week.