SSH and RPi Raspbian Jessie PIXEL 25 nov 2016

It seems the SSH default acess in Raspbian has been switched off in the latets (25 nov 2016) release.

But easy to get it going by creating an empty file in the root of the SD card with name ssh (jut that, no extension, no content required)

2016-11-25:
* SSH disabled by default; can be enabled by creating a file with name “ssh” in boot partition

So another little step to perform when preparing a SD card for headless first boot!

Oh, the system nags about password after enabling SSH:

sudo apt-get remove -y pprompt for the gui prompt

The CLI warning is raspberrypi-sys-mods, delete the file /etc/profile.d/sshpasswd.sh

Oberon version for the Raspberry Pi

(Found in the Oberon mailing list today!)

Josef Tampl has announced the availability of an Oberon version for the Raspberry Pi running 32-bit Raspbian.
You can download it from http://www.software-templ.com/shareware.html.

This version of Oberon is based on ofront 1.4, an Oberon-2 to C translator.
It comes with a set of command line tools and an integrated version based
on the Oberon V4 system.
Oberon modules can be compiled and linked into shared object libraries(.so) and loaded and unloaded
from within the Oberon system.

A complete Oberon interface for the popular ‘Wiring’ library (libwiring.so) is included.
This library can be used for convenient access to the Raspberry’s I/O hardware.

You may also want to download manual pages, additional fonts, and platform independent Oberon V4 source and resource files.
The Ofront source files as well as a makefile are hosted on Github.

Clean up Raspbian

Find out what takes up room

dpkg-query -W --showformat='${Installed-Size;10}\t${Package}\n' | sort -k1,1n

Obvious candidates:

Wolfram
Libre Office
Mathematica
Minecraft

post

Another Raspi.tv kickstarter!

 

RasPiO Pro Hat is a small Raspberry Pi add-on which…

  • protects the Pi’s ports in case you make a wiring error
  • arranges the Pi’s ports in numerical order to make tinkering easier
  • works “out of the box” with GPIO Zero – the new easy-to-use Python library included in Raspbian
  • requires no soldering or assembly
  • requires no software installation
  • includes a 170pt mini-breadboard to build your circuits on
  • gives you direct access to the ports if you need it
  • requires no additional resistors for use with LEDS
  • will have RasPi.TV-style tutorial experiments suitable for beginners and experts alike

 

post

Network scanning: find your RPi

When using a Raspberry Pi in your network it is very convenient to let it use DHCP to assign IP addresses, Setting up with fixed IP can be a pain to configure and be sure to use an address out of the IP range used by your DHCP router!
Nearly all DHCP servers try to assign the same IP address to a network device, by remembering its Mac address. And since Bonjour is running on current Raspbians, you can access the RPi with <RPI name>.local

But when you run headless, and have no clue, easy to use tools are available:

On an Raspberry/Linux machine use nmap.

Install
$ sudo apt-get install nmap

Scan your network
sudo nmap -sP 192.168.0.0/24

On a Windows system: Install Advanced IP Scanner, startup and press the scan button

On Android install from the Playstore ezNEtscan and press the Scan button.

 

 

Low level graphics Raspberry Pi: framebuffer

http://raspberrycompote.blogspot.nl/2012/12/low-level-graphics-on-raspberry-pi-part_9509.html

Basic, get screen info

http://raspberrycompote.blogspot.nl/2013/01/low-level-graphics-on-raspberry-pi-part.html

PArt 2 goes into actually drawing

http://raspberrycompote.blogspot.nl/2013/01/low-level-graphics-on-raspberry-pi-part_22.html

The details of the mapped display memory

and so on

http://raspberrycompote.blogspot.nl/2013/04/low-level-graphics-on-raspberry-pi-part.html

All code here: https://github.com/rst-/raspberry-compote

post

Ralink wireless device MediaTek MT7601

A2681-C4

I bought on ebay a year ago several wireless adapters with a large external antenna. Good range, recognized by wheezy and jessie Raspbian.
The lsusb command showed me those were RT5370 IC based Ralink devices, with driver support in the 3.x and 4.x kernel.

Witht he growing amount of Raspberry Pi’s here I thought it was a good idea to buy some more, and the Ebay adverts showed the identical looking device:

Mini 150Mbps 802.11N/G/B USB 2.0 WiFi Antenna Wireless Network LAN Card Adapter, about Euro 3

After several weeks they arrived, and the first test in the Windows PC’s showed a working wireless interface. So far so good.

In a Raspberry Pi alas, no WLAN0 device showed up. Time to troubleshoot!

lsusb showed there was a new USB device:


$ lsusb

Bus 001 Device 005: ID 148f:7601 Ralink Technology, Corp.

$ lsmod

<no device driver shown for this device>

The older working Ralink adapter had a different usb output:


$  lsusb

Bus 001 Device 006: ID 148f:5370 Ralink Technology, Corp. RT5370 Wireless Adapter

$ lsmod

rt2800usb 17716 0

So we have a new device, it is the MediaTek MT7601. Quick search with the ID 148F:7601 revealed this is indeed a new device. And it is supported with firmware in Linux kernel 4.2, the Raspbian kernel is still 4.1 and is not so far yet.

But a helpful post in the raspberrypi.org forums by MrEngman pointed me to the (now deprecated for kernel 4.2) to this command to load the driver:


$ sudo wget https://github.com/porjo/mt7601u/blob/master/src/mcu/bin/MT7601.bin -O /lib/firmware/mt7601u.bin

$ reboot

$ lsmod

..

mt7601u 73787 0

..

and all was well again.

Note this is tested on jessie

$ uname -a
Linux raspberrypwhplus 4.1.15-v7+ #830 SMP Tue Dec 15 17:02:45 GMT 2015 armv7l GNU/Linux

If you want to rebuild the driver, from the Mediatek driver source without debug info, follow this recipe.