Archive for the ‘General’ Category

The way forward for Pi-Kitchen

Posted: August 15, 2017 in General

So the Pi-Kitchen has been running for sometime now, and although I managed to solve many of the issues with configuring the Raspberry Pi out of the box, it has always remained an experimental project.

PiKitchen

The purpose of the Pi-Kitchen was to explore the ways in which we could provide a flexible method for configuring the Raspberry Pi.  It did that very well and I have used it successfully ever since…however…I suspect I was one of the few that actually managed to set it up and make use of it (I don’t mind too much since I was the one who wanted it…and it worked great for me).

There were even quite a range of recipes supported and development with around 25 supporting various settings and hardware out of the box, plus several automatically running demos which were great for setting up for events etc.

The Pi-Kitchen had two main issues:

  1. Difficult to setup – a user friendly GUI for install and config was in the works but time wasn’t available to complete it.  So it was quite a challenge to get running for others.
  2. Recipes become out-dated – having a smaller user-base (i.e. 1) and rather complex recipes meant that I only updated them when I next used them.  This was further compounded because Raspbian changed quite significantly during this time.

The experimental work has proven the pre-configuration and setup can work, and I’ve tried out some interesting ideas along the way, but a different approach is required to meet the full objective.

The dream remains…

The overall concept and idea still remains:

Turn the Raspberry Pi into a plug and play appliance

Essentially, I want to enable the Raspberry Pi to be configured completely up-front, via a GUI or from a supplied configuration.  Ideally, people would be able to provide a setup file and then it can be used with the latest Raspbian image to recreate their project.  After that, they need only insert the SD-Card and add power…no screen, no keyboard, no mouse (if suitable).

Potentially, the Pi-Kitchen was close to this but required specific recipe files carefully crafted to achieve this, and the non-trivial initial setup.

Raspberry Pi Appliances

Many projects are distributed as apt-get packages, or as git-hub repos, which require a operating system already setup and manually configured before you start.

Otherwise they are distributed as pre-built IMG files which have everything pre-installed.  This had several big problems:

  1. Typically the image ends up being out of date, since the base image often gets updated and the pre-built image does not.
  2. The user must configure the Raspberry Pi afterwards (i.e. to add their network settings or setup specific options) – so a screen and keyboard is often needed (Plug and Play fail) and a new install means you have to do it again (and again, and again)!
  3. All the details on how and what is installed within the IMG is hidden, so not only do you not know for sure what someone has put into the operating system but you don’t learn much about the project either.

The GoogleAIY is a great example of this (an awesome kit!), if it was setup using a supplied configuration which also allowed the required customisation to be done up-front then it would be possible to have made it an out-of-the-box appliance.  You’d configure and generate your SD-Card on a computer, insert it into the GoogleAIY kit and add power!

Boom-You have your google assistant ready and waiting for that first question “what does the fox say?” right off the bat.

aiy-projects

Image from RaspberryPi.Org

For those who haven’t used the GoogleAIY kit, it requires a number of steps to setup correctly on the Raspberry Pi after you have imaged the pre-built IMG file supplied, requiring a screen, keyboard, mouse and some careful config (not truly pure out of the box IoT experience).

By providing everything as a configuration script (even if it is tied to a specific release of OS) it allows the community to be able to understand (and perhaps update) the setup which is packaged into these pre-built IMG files.  This would also ensure updates and fixes are pulled in and enabling these projects to develop further within the Raspberry Pi ecosystem over time.

Enter PiBakery stage right…

blocks-on-workspace

Image from PiBakery,Org

The PiBakery has been developed by David Ferguson and provides another solution for configuring Raspberry Pi SD-Cards.  It provides an excellent solution for setting up the SD-Card out of the box and provides a very neat interface for customising the configuration quickly and easily.

In fact, the whole thing works very nicely and is a lot better than what I was planning for the Pi-Kitchen (without requiring time I don’t have to develop it!).  If used correctly, and developed with a few additional blocks, this could easily be a platform by which people could create and share projects that enable the Raspberry Pi to be a proper plug and play solution.

So… hopefully we can help with it and build up the recipes available so that it is possible to create that complete Raspberry Pi setup from a configuration file and allow users to customise it before they install and power up.  To get that plug and play dream!

NOOBS / PINN Image support

The PiBakery functions by using a customised IMG file (based on Raspbian) which has a few scripted inserted to support the execution of the PiBakery configuration when the Raspberry Pi boots up.

This does mean that every time the official Raspbian image is updated, David has to update his image file (and that has to get pushed to your local PiBakery installation).  It also means that in order to support other variants (such as Raspbian-Lite, OpenElec or possibly Arch Linux and Ubuntu), each one would need the custom PiBakery files inserted manually and downloaded.

Using the methods used by Pi-Kitchen, we can use Procount’s NOOBSCONFIG (with NOOBS) or PINN (Procount’s advanced version of NOOBS), which will allow the required custom files to be added to the installed operating system post install.

The advantage of using PINN over NOOBS is that not only does PINN support the file injection methods without any changes, but Procount has enabled support for a much larger range of source images (in .IMG and .tar.xz formats) and allows source images to be served from a local server or even from a connected USB drive.

1

Image from matthuisman.nz

I’ve successfully used PiBakery in combination with PINN and a clean Raspbian image, to install a PiBakery configuration automatically.  This required 5 basic steps:

  1. Copy PINN/PINN-Lite to a clean SD-Card.
  2. In order to support a standard NOOBS type installation, the resulting SD-Card structure is slightly different to a clean IMG file type install.  NOOBS creates a FAT formatted recovery partition, this changes which partition will be visible by PiBakery from the host operating system.  Therefore, a few mods to these PiBakery files are needed to support different locations for the PiBakery configurations.  This requires removeFirst.py, removeNext.py and runScript.py to check for the PiBakery configurations in the Recovery partition as well as the boot partition.  I’ve prototyped these changes already and shown this to work with a clean Raspbian image.
  3. Create the configuration to copy the PiBakery configuration files to the correct place in the operating system and setup PINN to perform an automated install.  Currently, I’ve added a Pi-Kitchen recipe to do this, but practically we’d only need this single configuration so these can be created as a standalone configuration to be copied to the SD-Card (along-side the configurations generated by PiBakery).
  4.  Fool PiBakery to think it has already installed the OS so that it is ready to “update” the configuration (otherwise it’ll try to format and install the custom PiBakery image).  This is achieved by creating a folder called PiBakery and adding an empty blocks.xml file onto the SD-Card.
  5. Create your custom PiBakery configuration using the super nice block interface to build your custom setup, enter your settings, and update the SD-Card.

The SD-Card will be ready to power on and PINN will install the OS and then PiBakery will perform all the customisations.

In theory, this can be integrated into a single option within PiBakery (or in PINN) so the whole thing is as seamless as possible.

Extra Blocks

I’ll talk about some useful extra blocks next time, which will allow some of the customisations I’ve come to enjoy with using Pi-Kitchen, and also some which will streamline deploying your own projects via PiBakery.

Thoughts??

Hopefully David Ferguson will appreciate the concept and will be happy to integrate some of these ideas into his excellent project.

PiBakery and Procount’s PINN could make a rather nice combination, and perhaps a new era as the Plug and Play Raspberry Pi appliance.

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New book review!

Posted: December 20, 2016 in General

Check out my new review:

The Hardware Hacker – Andrew “bunnie” Huang

hardwarehacker_cover

Available January 2017.

Experimenting with a few things…

Posted: July 20, 2016 in General

Once again, time has gone on and I’ve not added much for a while to the site.  However I’ve been playing around with a few things which have been lots of fun.

So I’ll keep adding to this post a little at a time and take you through a few of the interesting things I’ve got my hands on…  No spoilers..yet..but a few really excellent things (at least I think so).

Using Micro-Python with the NodeMCU Board

As usual I’ve written myself some notes on getting this setup, and I fully intend to share (once I get time to write it properly).  However some very quick lessons learnt…

Lesson 1: Micro Python is very nice, and you can use a Python-like terminal with the device by connecting through the serial.  Very swish…but frankly no cigar yet.

Lesson 2: Micro Python with a Wifi device like the ESP8266 on the NodeMCU board is great…but remember the ESP8266 Wifi settings are separate to the firmware, so you may need to ensure it is set to station mode first, before the micropython firmware will reset it.

Lesson 3: When you get webREPL running…we are getting better  – developing over Wifi yes please!  If it isn’t running once you’ve programmed the firmware (which it wasn’t on mine) you’ll never be able to connect using the webREPL console page (which is a html page – you can download a local copy or visit http://micropython.org/webrepl/).  Don’t get annoyed it doesn’t work until you’ve started it!

Lesson 4: Use the serial python console to start webREPL on the device as follows:

>> import webrepl
>>> webrepl.start()
WebREPL daemon started on ws://192.168.4.1:8266
Started webrepl in setup mode
>>>

Lesson 5: You must connect to the device via Wifi to use the web console!  Connect to the device via the AP it provides “MicroPython-ffffff” with default password “micropythoN).

First time you connect via the console (using the address shown when it starts) you’ll set a new password.  Then reset the board and reload webrepl as before.

Lesson 6: Unless you want to always manually start webrepl use the boot.py file and upload it.  This will run on power up!

boot.py

import webrepl
webrepl.start()

Lesson 7: Micro Python is a little annoying…it supports files so you can upload .py files and import them…BUT there is no editing via the webREPL console.  So edit and upload? No not quite!

Lesson 8: Uploading new files and “import mymodule” isn’t enough to update your code!  Import will not reload a module if it is already loaded…deleting a module (using “del mymodule”) will remove it but it is still cached so it will still not update.  WHAT A PAIN!

Lesson 9: After a few experiments (and a hint from @mnelsoneorm1 to checkout https://forum.micropython.org) managed to work out a way to do it.  Sometime later, I wrapped up all the useful bits into a util.py file, which I loaded at startup as well.

boot.py

import webrepl
import util
webrepl.start()

util.py

def readfile(file="boot.py"):
  with open(file,'r') as thefile:
    data = thefile.read()
    print(data)

def delfile(file):
  import os
  os.remove(file)

def reload(module):
  import sys
  del sys.modules[module]

Lesson 10: The upload might not upload a new version of your file…You may need to upload a different file first to ensure the newer one is reloaded into the browser.

Final lesson is NeoPixels are simply awesome (and deceptively easy)!

neo.py

import machine,neopixel
v=0.5
print(v)
NUM=24
np=neopixel.NeoPixel(machine.Pin(4),NUM)
OFF=off=(0,0,0)
R=r=(255,0,0)
G=g=(0,255,0)
B=b=(0,0,255)
Y=y=(255,255,0)
C=c=(0,255,255)

def clear():
  all(OFF)

def all(val):
  for i in range(NUM):
    np[i]=val
    np.write()

def pattern(val1,val2,val3,val4):
  for i in range(NUM/4):
    np[(i*4)]=val1
    np[(i*4)+1]=val2
    np[(i*4)+2]=val3
    np[(i*4)+3]=val4
  np.write()

def demo():
  import time
  for i in range(10):
    pattern(R,R,G,B)
    time.sleep(0.1)
    pattern(B,R,R,G)
    time.sleep(0.1)
    pattern(G,B,R,R)
    time.sleep(0.1)
    pattern(R,G,B,R)
    time.sleep(0.1)

np[0]=(255,0,0)
np[1]=(0,128,0)
np[2]=(0,0,64)
np.write()

GPIO Zero Hero.

I thought it was time I took at GPIOZero by Ben Nuttall.  You can see my write up on my Guide to…Embracing GPIOZero.

This also includes a solution for using GPIO.BOARD (physical pin numbering) with the GPIOZero library.  The best part is that you can keep using GPIO.BCM (BCM numbering) by default and just enable GPIO.BOARD when required.  WIN-WIN-WIN!

RPiGPIOBasic

GPIO.BOARD Physical pin number, just as it says on the tin.

Pi Zero USB-LAN Fan.

I’ve also been playing around with my PiZero.  Which still makes an excellent USB-LAN Device.  You can see the whole Pi-Kitchen process in my Using Pi-Kitchen to “bake” a Raspberry Pi Zero as a USB LAN Device video.

cz1bdigwwaeopxs

Smaller than a Bourbon????  Well not really (it is a super size Bourbon)

 

Pi-Stop to go.

Also, I’ve added some details of the Pi-Stop python module which I use in my workshops.

czydpoiwaaeglij

The Pi-Stop is plug and play!

This allows easy plug and play without the wires and hassles with pin numbers.  Just select one of the standard locations A, B, C and D (plus A+ and B+ for Model +/ RPi 2) and away you go!

A neat little HDMI screen.

I also got a nice little HDMI screen which although only being 5″ provides 800×480 resolution and a resistive touch screen.  The config will get added to the Pi-Kitchen in the next update (proto-type recipe is working well).

czaxcphxeaedw2m

The screen is from Bandgood.com and was about £20 (GBP) and runs well via a standard USB power pack (surprisingly low power and includes a switch to turn off the back-light too).

It is perfect for my Pi-Kitchen testing since unlike SPI/I2C/DSI interfaces, it works well enough without extra configuration.  The additional configuration makes the display fill the screen and enable the touch screen.

This makes a Model A with keyboard a handy lightweight “kit-to-go” set-up.

 

That is all for now!  Enjoy.

Time…it just keeps on rolling…

Posted: January 18, 2016 in General

What a year it was for 2015.  Taking a look my blog I’ve not posted for quite some time, but I have been very busy with a lot of other stuff.

Here’s a quick overview of the latest things on the plate for today…

Book review…

First off we have a review of Learn to Program with Minecraft by Craig Richardson.  I had a go with it yesterday and introduced some Python programming to our family Minecraft actives.

IMG_20160116_200201

Minecraft on the Raspberry Pi – a small keyboard and mouse is ideal for smaller hands!

PiZero enters the Pi-Kitchen and comes out a fully baked USB-LAN device

I’ve managed to package the required modifications to make a Pi Zero (and Model A/A+ Raspberry Pi) into recipes for the Pi-Kitchen.

For more details see the Git-Hub:

https://github.com/PiHw/Pi-Kitchen

To get started use:

Pi-kitchen – Start Baking

See the following video to see the whole Pi-Kitchen process in action and some of the features that can be pre-configured ready for power up.

 

Some other things I’ve been playing with…but not had time to post about…

IMG_1658

Pi-Stop workshop at Digimakers at the @Bristol science centre, along with a selection of books on show.

6623OT_08_027

Movement tracking with the Raspberry Pi Camera module!

 And much much more!

 

 

Fun time @Digi_Makers!

Posted: February 28, 2015 in General

Just a quick post (after a long but very fun day)…

Firstly many thanks for all those who attended the Pi-Stop workshop, a super-bright bunch you all were!  Hope you all had as good a time as I did, I shall return will some more challenges next time.

The workshop materials are available on git-hub, along with other guides and information.

For those who had a browse of my books most should be available on Amazon – or for the No-Starch-Press books from their website)

2015-02-28 21.53.42

Good news, my book (and others) is currently 25% off at Packt Publishing (using code PRINT25 at checkout, valid until 6th March 2015).

So you were lucky enough to receive a Raspberry Pi for Christmas or perhaps you’ve had one a while and wasn’t too sure what to do with it then read on for some tips on how you can do more with this wonderful little computer.

1. Add a Wifi Adaptor

Even if your Raspberry Pi is a model B or B+ (which has a built in network connection) going wireless can have many advantages.

RaLink Wifi Adaptor

Not only does it make it easier to setup your Raspberry Pi in a location which is convenient for you (you don’t need to be next to a network socket or your router) but it means if you are using your Raspberry Pi remotely i.e. without a screen (see my Guide to Remote Connections) you just need to add power to run.

Model A Plus Wifi Setup

A Wifi adaptor will require some additional configuration, so be prepared to set it up before you use it (also be warned that you must plug in the Wifi dongle before you power up the Raspberry Pi – particularly for the older models – otherwise it will cause the Raspberry Pi to reboot).

The Pi-Kitchen can help greatly with the Wifi setup and can allow you to configure everything up front so when you install via NOOBS it will work immediately!

Although remember, if you are using an older model B or a model A (or A+) adding a USB Wifi dongle will take up a USB socket, so you may be limited to using either a mouse or a keyboard (or neither on a model A/A+).  However there are ways around this limitation too:

  1. Use a USB hub (ideally a powered one)
  2. Use a wireless keyboard and mouse set since they typically have a single USB wireless RF dongle for both
  3. You can also use a bluetooth keyboard/mouse – but remember you will need to configure these with the Raspberry Pi before you can use them.
  4. There are also keyboards which have a trackpad built-in (in place of the number pad), these use a single USB connection so are rather handy for the Raspberry Pi.

keyboard

2. Get a dedicated screen

ScreenSetup

Generally if you are planning on using the Raspberry Pi with your kids, then having a dedicated screen you can setup specifically for their use is by far the best solution.  Don’t forget that the whole idea of having a cheap computer is so that kids can experiment freely with it without worrying about causing damage to expensive parts or hogging the use of the family computer/TV.

TIP: For particularly young kids it can even help to have a 2nd setup for you to use, that way you can go through the same steps as them and if they get stuck demonstrate the answer.  By having a 2nd setup (even if you use a laptop and remote connection) you avoid the temptation to take hold of the mouse or keyboard and do it for them: you can show them and they can copy.  That way the sense of achievement is far greater as everything they do has been totally their own work.

When the Raspberry Pi was first released HDMI to VGA adaptors were rather expensive, bulky and often required external power.  This typically meant the best option was to find a screen which supported HDMI (such as a digital TV) and use that.

HDMI to VGA Adaptors:

HDMI2VGA

However these adaptors are now relatively cheap (£8 or less) very compact and will run directly from the Raspberry Pi.  These low cost adaptors are ideal if you have a spare screen available or an old computer, as HDMI compatible monitors are still quite expensive and it probably overkill to run a £30 computer with.  You may even find that your IT department or a local company will have unwanted VGA monitors or screens available, as newer PCs no longer support analogue connections they will still be ideal for the Raspberry Pi.

You may need to use slightly different settings with these adaptors, the config.txt file controls these settings (initially you can use hdmi_safe=1 to check everything is working).

disable_overscan=0
hdmi_drive=2

config_hdmi_boost=4

For more details see config.txt file.

 

 

 

DVI to VGA Adaptors:

6623OT_01_003

If you have a screen which supports DVI-D even better, as HDMI to DVI-D adaptors are around £2 at most and generally will result in a better signal (by remaining as a digital output).

Also remember if you use an adaptor for the HDMI output to convert to DVI-D or VGA audio will not be provided by the monitor so you may need additional speakers for sound (or a suitable cable if your screen has built-in speakers).

Again, there are a few other alternatives for display output:

Analogue Output:

The Raspberry Pi does have an analogue output (which can connect to older TVs though composite and SCART connections) but for most situations the display is low resolution and hard to see.  I would not recommend this method for general use except as a fall back when configuring things.  When using the Raspbian desktop you find that most programs will not physically fit on the screen making it impossible to click dialogue items or use them effectively.

Gert VGA Adaptor:

The Gert VGA adapter board is available from PiSupply (click on image to go to the shop).

The Gert VGA adaptor board is available from PiSupply (click on image to go to the shop).

This little board plugs (designed by the Raspberry Pi foundation’s Gert-van-Loo) directly onto the newer Model A+ or B+ Raspberry Pi GPIO header and allows you to drive a VGA monitor directly from the Raspberry Pi itself.  This allows you to connect directly to a VGA screen and also supports a 2nd display (via HDMI for example).  However it does use up most of the GPIO pins (4 are left over which can still used for hardware).

Note: If you have an older Raspberry Pi model (Model A or Model B) then this adaptor will not work (it required the newer 40 pin GPIO connection).

Use Remote Connections:

By using VNC, X11-Forwarding or SSH you don’t even need to have a screen (see my Guide to Remote Connections).

However, it is always helpful to have a screen available for those times when there is a problem connecting to the Raspberry Pi and you need to trouble-shoot the issue (you will fix your problem much quicker if you can see what is happening).

Generally if you are planning on using the Raspberry Pi with your kids, then having a dedicated screen you can setup specifically for their use is by far the best solution.  Don’t forget that the whole idea of having a cheap computer is so that kids can experiment freely with it without worrying about causing damage to expensive parts or hogging the use of the family TV/computer.

TIP: For particularly young kids it can even help to have a 2nd setup for you to use, that way you can go through the same steps as them and if they get stuck demonstrate the answer.  By having a 2nd setup (even if you use a laptop and remote connection) you avoid the temptation to take hold of the mouse or keyboard and do it for them: you can show them and they can copy.  That way there is a far greater sense of achievement as everything they do has been entirely their own work.

3. Get some educational resources!

Everyone needs to start somewhere and using some of the vast array of resources available is an excellent way to get started.

The MagPi Magazine

There are 30 issues of the MagPi available covering over 2 years of  the Raspberry Pi.

There are 30 issues of the MagPi available covering over 2 years of the Raspberry Pi.

This community led magazine is available for download for FREE from the MagPi website, and is a perfect resource for those starting out with the Raspberry Pi and also to get some more advanced ideas too.  You can support the MagPi by purchasing printed versions of the magazine from the many retailers (see the site for details).

Raspberry Pi foundation educational resources

The Raspberry Pi resources are split into three sections: Teach, Make and Learn.

The Raspberry Pi resources are split into three sections:
Teach, Make and Learn.

The Raspberry Pi website has a whole section of resources available, a perfect place to get started and learn the basics of using the Raspberry Pi and starting your own projects.

Get a book

For those bigger projects and a more complete guide a good book makes an excellent resource.  Ideally you will find that you will often find the solutions to what you need just by grabbing it off the shelf and looking the answer up (a good reference book will keep being useful long after you’ve read it once).

There are lots of great Raspberry Pi books out there, but I would like to recommend my own one as a comprehensive guide to what you can achieve with the Raspberry Pi.

Raspberry Pi Cookbook for Python Programmers

Get the most out of the Raspberry Pi and unleash its huge potential using Python.

You can read more about in the sections above on this site, and also see what other’s think by reading the excellent reviews (of which I am very thankful for) I’ve had on Amazon.  The book is also available from other retailers, or direct from the Packt website.

4. Get started with hardware

The Pi-Stop

LogoDesignVertOp

As any hardware or embedded software engineer will tell you, the first step to any project is to get some lights flashing.  For kids the ability to control something which they can physically pick up and handle is a huge incentive and can make following guides and tutorials far more engaging.

Pi-StopGuides

The Pi-Stop is an excellent starting point, fitting directly onto the Raspberry Pi it provides a excellent starting point for interfacing with hardware on the Raspberry Pi.  There are lots of resources available to get you started and also a number of workshops and tutorials to follow.

Python Pirate Workshop Setup - 3 small treasure chests, 1 large (with gold coins), Combination Padlock, 4 Raspberry Pi with Pi-Stops (plus PSU/SDCards), Maps and Worksheets

The Pi-Stop was jointly designed by PiHardware (this site!) and 4Tronix as a low-cost and easy to use add-on for workshops and home use.  Of course once you’ve got used to controlling hardware they are excellent for debugging and indicating different operations while the Raspberry Pi is running, and can also be used with other micro-controllers too.

They are available from 4Tronix and now also from CPC (Farnel).


More tips to supercharge your Raspberry Pi coming soon!