Featured Posts

UK TV Times – TV listings in a firefox and chrome addon

Posted by Mike Redrobe | Posted in browser add-ons, Software | Posted on 19-06-2012

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The great TiVo PVR records all the TV I could possibly want, but I sometimes still look at the TV guide to see if it’s worth getting up from sitting at the PC. Of course there are various TV Guide websites, but none of that is as convenient as a single click popup in your browser.

Here’s a Chrome / Firefox addon I wrote to show TV Listings with a single click:

V 1.0


  • View now and next TV listings with a single click
  • Shows 20 most popular channels

Coming soon

  • Searching and reminders

  • Customisable channel list

Get it yourself direct from:

UK TV Times for Firefox

and for chrome:

UK TV Times for Chrome
Youtube video

ebay live – firefox and chrome addon

Posted by Mike Redrobe | Posted in browser add-ons, Software | Posted on 13-06-2012

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This week I wrote another browser add-on for firefox and chrome, this time to keep track of your eBay watched items and sales in a handy window, accessible by a single click.

V 1.0


  • Track your eBay activity with a single click.
  • Opens a popup widget with your watched item list already displayed.
  • Links at the bottom for quick access to
  • Watched items
  • Selling items,
  • Sold Items
  • My eBay


Get it yourself direct from:

eBay Live for Firefox

and for chrome:

eBay Live for Chrome
Youtube video

Balancing robot – without gyros

Posted by Mike Redrobe | Posted in Arduino, robots | Posted on 25-05-2012

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Bot balancing without gyros … for a few seconds at least

No gyros, no accelerometers – only a sonar ranger and lots of code.

The motors used are standard servos modified for continuous rotation, sonar sensor is a HC-SR04 as detailed in a previous post

Code ? Well here’s a simplified portion of the PID loop:

    int Drive = 0; // PWM value sent to Servos
    int Error[5]; // array of 5 Error elements
    int P = 0; // proportional term
    int I = 0; // integral term
    int D = 0; // derivative term

    #define Current 0
    #define Sum 1
    #define Last 2
    #define SecondToLast 3
    #define Delta 4

    int PID() {
    Error[Current] = SetPoint – Ptime;
    P = Error[Current] * Kp;
    Error[Sum] = Error[Current] + Error[Last] + Error[SecondToLast];
    I = Error[Sum] * Ki;
    Error[Delta] = Error[Current] – Error[Last];
    D = Error[Delta] * Kd;
    Drive = P + I + D;
    Error[SecondToLast] = Error[Last];
    Error[Last] = Error[Current];

    return Drive;

Ultrasonic robot avoids walls

Posted by Mike Redrobe | Posted in Arduino | Posted on 21-05-2012

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Using an ultrasonic sonar ranger to avoid walls – and people’s feet – before hitting them:

At first I was getting plenty of false readings, so here’s the first run, pausing and verifying before turning:

With faster code, and not stopping:

Improved accuracy, so it detects smaller objects like feet:

Arduino and SR04 ultrasonic sensor – robot eyes !

Posted by Mike Redrobe | Posted in Arduino | Posted on 20-05-2012

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Hooked an SR04 ultrasonic sensor to my arduino board – robot eyes !

Ranger sensor uses sonar to give accurate distance measurement to objects or obstacles placed in front of it. They’re surprisingly sensitive / accurate – I was able to reliably measure to a millimeter at 15cm range.

These sensors are also now VERY cheap £2.37 (4$) delivered from HK, and accurate to a few mm.

Added a servo for visual feedback:

Arduino code is basically sending a trigger on one pin, receiving a timing value on another,
which can then be converted into a distance:


    digitalWrite(Trig_pin, LOW);
    digitalWrite(Trig_pin, HIGH);
    digitalWrite(Trig_pin, LOW);
    duration = pulseIn(Echo_pin,HIGH);

BBC News add-ons for firefox and chrome

Posted by Mike Redrobe | Posted in browser add-ons, Software | Posted on 17-05-2012

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Following on from my recent add-ons, here’s a handy plug-in to display latest bbc news headlines.

Instead of opening a tab, this opens a faster mini window on a single click:

So go get the add-on “Latest BBC News” for both firefox and chrome:

V 1.0


  • Get all the Latest BBC News headlines with a single click.
  • Opens a popup widget with the latest news headlines.
  • Links at the bottom to show all sections:
    Technology, Health, Entertainment etc


Get it yourself direct from:

BBC News for Firefox

and for chrome:

BBC News for Chrome
Youtube video

Hot UK Deals – add-ons for firefox and chrome

Posted by Mike Redrobe | Posted in browser add-ons, Software | Posted on 10-05-2012

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An avid bargain hunter, I often keep an eye on HotUKDeals.com for the latest deals,
and following on from my recent add-on for ebuyer’s website, I thought I’d make a more convenient way of checking the site.

Instead of opening a tab, this opens a faster mini version of the site on a single click:

It also adds the oft-requested feature of page numbers at the top of threads on the main site:


Much better !

So go get the add-on “Top UK Deals” for both firefox and chrome:

V 1.1.0


  • Opens a fully functional small version of the HUKD website
  • You can
    – sort by date,
    – sort by recently comments

    – view/post comments

  • You can even post a new deal direct from the popup !
  • Also makes minor edits to the main HotUKDeals site :
  • – adds pagination box to the top of the comments page [ 1.,2.3…last]


Get it yourself direct from:

Top UK Deals for Firefox

and for chrome:

Top UK Deals for Chrome
Youtube video

eBuyer add-ons for firefox and chrome

Posted by Mike Redrobe | Posted in browser add-ons, Software | Posted on 19-04-2012

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Sometimes a website redesign loses useful features, this was the case recently when popular computer & electronics retailer eBuyer.com updated their site.

Gone were long searchable list of products, with a limit of 10 per page, and no option to add to cart directly from the product list, which makes comparing products / mass adding a shopping list very laborious.

So like any good techie, I set out to fix matters by writing a chrome extension and firefox add-on to alter web pages on-the-fly to my liking, and bring back the ease of use.

EBuyer’s site without add-on installed:

Note the large banner before product results, and only 10 per page, now here’s with the add-on enabled:

and with add to cart buttons added:


Much better !

Without further ado, here’s the add-on “eBuyer Tidy” for both firefox and chrome:

V 1.0.6

  • Add to Cart directly on search / list pages.
  • Works with categories properly now and retains special offers
  • Forum link at the top
  • shows a selected number of products per page ( not restricted to 10!)
  • Removes the big banner before search results (leaves it on the main index page)
  • options page ( for number of items shown)


Get it yourself direct from:

eBuyer Tidy for Firefox

and for chrome:

eBuyer Tidy for Chrome
Youtube video

Run Android apps on your PC

Posted by Mike Redrobe | Posted in Phones | Posted on 04-04-2012


Run your Android apps on your PC with Bluestacks

The BlueStacks app player for running Android apps on Windows has taken a major step forward today with the release of its first beta, which can run even graphics-intensive Android apps on desktop PCs.

The BlueStacks beta (download) leverages a new, patent-pending technology that the company has developed called LayerCake, which does two things necessary for running Android apps on Windows. First, it powers the app on hardware that it wasn’t originally intended to run on. That’s basically the ARM to x86 conversion which runs the apps, and it comes with the blessing of one of AMD’s head honchos.

“LayerCake is a disruptive technology that enables PC manufacturers to bring the best of the Android ecosystem to their customers. We are excited to work with BlueStacks to make the emerging Android mobile apps market part of the broader computing arena,” Manju Hegde, corporate vice president, Content, Applications and Solutions at AMD, said in BlueStacks’ statement announcing the new beta.

LayerCake also includes hardware graphics acceleration that wasn’t available in last year’s BlueStacks alpha. This means that it uses your PC’s graphics card to make graphics-intensive apps, including Android NDK games like Air Attack HD, run more smoothly:


Arduino Starter Kit

Posted by Mike Redrobe | Posted in PC Hardware, Technology | Posted on 01-03-2012



Well, what is Arduino ?

Arduino is an open-source platform for microprocessor projects, or as the Arduino website puts it:

“Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It’s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.”

Basically its a little CPU that you can program in C, and easily attach servos and sensors to. The open-source nature means there’s a wealth of example code and libraries out there to modify for your own use.

Available in the UK from oomlout for around £50

So what do you get ?

  • Arduino Prototyping Bundle (Arduino Uno board (328), breadboard & acrylic holder)
  • 75 Piece Jumper Wire Bundle
  • Printed 29 page Experimenter’s Guide
  • 11+1 Breadboard Layout Sheets
  • USB Cable
  • Multi-compartment Plastic Storage Box
  • 9v Battery – Arduino Adapter
  • Loads of components
    • 5mm Red LEDs (x10)
    • 5mm Green LEDs (x10)
    • 10mm Red LED (x1)
    • Toy Motor (x1)
    • Mini Servo Motor (x1)
    • 8-Bit Shift Register (74HC595) (x1)
    • Piezo Element (x1)
    • Pushbuttons (x2)
    • Potentiometer (10k) (x1)
    • Photo Resistor (x1)
    • Temperature Sensor (TMP36) (x1)
    • Relay (5v DPDT) (x1)
    • Transistors (2N222A) (x2)
    • Resistors (560 Ohm x25, 2.2k Ohm x3, 10k Ohm x3)
    • Diodes (1N4001) (x2)

The manual goes through 11 projects, from a simple blinking LED to using shift registers and relays, as well as giving a brief overview of how to program for the board and some more complicated tasks after you’ve built each of the individual projects (such as making the blinking LED fade instead).