N900 with a Slice of Raspberry Pi
It may not come as a surprise to anyone who regularly reads my column that I tried to be first in line to order the Raspberry Pi. I mean, what's not to like in a $35, 700MHz, 256MB of RAM computer with HDMI out that runs Linux? In the end, I didn't make the first batch of 10,000, but I wasn't too far behind either. So, now that I've had a Raspberry Pi for a week, I've already found a number of interesting uses for it. You can expect more Raspberry Pi columns from me in the future (possibly including an update to my beer fridge article), but to start, in this article, I talk about a combination of two of my favorite pocket-size Linux computers: the Raspberry Pi and my Nokia N900.
At first you may wonder why combine the two computers. After all, both are around the same size and have similar initial hardware specs. Each computer has its own strengths, such as cellular networking and a touchscreen on the N900 and an Ethernet port and HDMI video output on the Raspberry Pi. In this article, I explain how to connect the N900 to the Raspberry Pi in a private USB network, share the N900's cellular connection, and even use the N900 as a pocket-size display. In all of the examples, I use the default Debian Squeeze Raspberry Pi image linked off the main http://www.raspberrypi.org page.
Set Up USB Tethering
The first step to using the N900 with the Raspberry Pi is to set up a private USB network between the two devices. There are a number of ways to do this, but I've found that the most effective way is via the Mobile Hotspot application on the N900. This program started as a way to allow you to tether your computer with your N900 by turning the N900 into a wireless access point; however, because it uses WEP for security, I always favored using Mobile Hotspot's lesser-known USB networking option. That way, I not only get to tether my laptop, but because tethering uses up quite a bit of battery power, by being plugged in over USB, my laptop can keep my N900 charged as well.
By default, the Raspberry Pi is not set up to enable USB networking, but luckily, this is easy to set up. Just log in to your Raspberry Pi and edit the /etc/network/interfaces file as root. Below where it says:
iface eth0 inet dhcp
iface usb0 inet dhcp
Now, launch the Mobile Hotspot program on your N900 and make sure it is configured so that the Interface is set to USB, as shown in Figure 1. Then connect the Raspberry Pi to your N900, which should prompt you to select between Mass Storage mode or PC Suite mode. Choose PC Suite mode, and then click the Start button on the Mobile Hotspot GUI. This automatically should set up the USB network for you, and you should see logs like the following in your Raspberry Pi's /var/log/syslog:
Jan 1 01:04:44 raspberrypi kernel: usb 1-1.3: new high speed ↪USB device number 5 using dwc_otg Jan 1 01:04:44 raspberrypi kernel: usb 1-1.3: New USB device found, ↪idVendor=0421, idProduct=01c8 Jan 1 01:04:44 raspberrypi kernel: usb 1-1.3: New USB device ↪strings: Mfr=1, Product=2, SerialNumber=0 Jan 1 01:04:44 raspberrypi kernel: usb 1-1.3: ↪Product: N900 (PC-Suite Mode) Jan 1 01:04:44 raspberrypi kernel: usb 1-1.3: ↪Manufacturer: Nokia Jan 1 01:04:47 raspberrypi kernel: cdc_ether 1-1.3:1.8: usb0: ↪register 'cdc_ether' at usb-bcm2708_usb-1.3, ↪CDC Ethernet Device, 66:77:ea:fa:12:8c Jan 1 01:04:47 raspberrypi kernel: usbcore: registered new ↪interface driver cdc_ether Jan 1 01:04:47 raspberrypi kernel: cdc_acm 1-1.3:1.6: ↪ttyACM0: USB ACM device Jan 1 01:04:47 raspberrypi kernel: usbcore: registered ↪new interface driver cdc_acm Jan 1 01:04:47 raspberrypi kernel: cdc_acm: USB Abstract ↪Control Model driver for USB modems and ISDN adapters
Figure 1. Mobile Hotspot Configured for USB Tethering
The point-to-point network that is set up turns your N900 into a gateway with the IP address of 10.8.174.1, and your Raspberry Pi is given the IP 10.8.174.10, which you can see from the output of ifconfig on the Raspberry Pi:
usb0 Link encap:Ethernet HWaddr 66:77:ea:fa:12:8c inet addr:10.8.174.10 Bcast:10.8.174.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:309 errors:0 dropped:3 overruns:0 frame:0 TX packets:204 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:25703 (25.1 KiB) TX bytes:30676 (29.9 KiB)
Because the N900 is set up as the gateway, your Raspberry Pi can use that
cell-phone network for any outbound connections without having to worry
about plugging in the Ethernet port. In addition, if you start the SSH
service on the Raspberry Pi (
sudo service start ssh) or better, if you
make sure it's enabled at boot, you can
ssh into your Raspberry Pi from
the N900 with
ssh firstname.lastname@example.org from a terminal. If for some reason
when you try to
ssh to this IP, you get a "no
route to host" error,
investigate your Raspberry Pi logs and confirm that you truly are getting
the 10.8.174.10 IP. I found on my system that occasionally I would get a .11
or .12 IP instead.
Kyle Rankin is a VP of engineering operations at Final, Inc., the author of a number of books including DevOps Troubleshooting and The Official Ubuntu Server Book, and is a columnist for Linux Journal. Follow him @kylerankin.
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
Join Linux Journal's Mike Diehl and Pat Cameron of Help Systems.
Free to Linux Journal readers.View Now!
|The Firebird Project's Firebird Relational Database||Jul 29, 2016|
|Stunnel Security for Oracle||Jul 28, 2016|
|SUSE LLC's SUSE Manager||Jul 21, 2016|
|My +1 Sword of Productivity||Jul 20, 2016|
|Non-Linux FOSS: Caffeine!||Jul 19, 2016|
|Murat Yener and Onur Dundar's Expert Android Studio (Wrox)||Jul 18, 2016|
- The Firebird Project's Firebird Relational Database
- Stunnel Security for Oracle
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- Managing Linux Using Puppet
- SUSE LLC's SUSE Manager
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- Doing for User Space What We Did for Kernel Space
- SuperTuxKart 0.9.2 Released
- Google's SwiftShader Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide