Arduino LCD Keypad Shield – Basic Menu System

LCD1After recently purchasing an LCD and Keypad Shield for my Arduino Uno. I thought I best test it out and write a quick sketch to use with it.

The shield has a 16×2 (LCD1602) LCD and 6 Button Keypad , extremely useful for controlling your projects without hooking the Arduino board up to anything. I believe this cost me just under £4 delivered and is well worth the money.

I have made a basic options selection menu which will allow you to scroll through a list of entries and select one of them, using the least amount of screen updates. It doesn’t yet support sub-menus, but it’s dead easy to implement using this code found below.

Click here to read more..

Arduino Open Source Electronics Platform – What is it?

Arduino Uno R3You’ve probably noticed that quite a few posts on here talk about an Arduino, however we haven’t really gone into detail about what one is or where to get one from.

An Arduino is an open source platform that is based on a microcontroller and an easy to use development environment for building electronic projects. The amount of uses for an Arduino is infinite, you use pins on the board to communicate with other hardware such as sensors, motors, lights, switches, and other circuits or systems.

The development environment for the Arduino is also open source; the programming language is based on Wiring – The IDE is downloadable from the Arduino.cc website and is available for Windows, Linux and MAC OSx.

So, how do I get an Arduino?

You have a few choices here. The first one is if you’re familiar and comfortable with building circuits and have experience with electronics you can build your own. The Arduino is an open platform and there are plenty of guides available to build it from scratch.

The other option is to buy it from the Arduino.cc store, or official reseller. You can normally just buy this as an individual product, or get a kit if you need the additional components. The third option is to buy a cheaper, compatible version of the Arduino – again, as this is open-source there is a number (if not hundreds) of manufacturers. Keep in mind the last option that you get what you pay for (e.g. sometimes cheaper/lower quality parts)

You can find a link to the Arduino Store here. Or a list of distributors here.

There are multiple versions and types of Arduino

There are many types of Arduino, the version you start with entirely depends on your experience and preference, or if you have a project in mind already, your requirements. So what versions of Arduino are there?

 

Which one is right for me?

This all depends on what you want to gain from it. If you’re just starting out the Arduino Uno is a great product to begin with. This will allow you to get to grips with using an Arduino, there are also a good variety of shields available.

If you have any experience with programming then that will be a huge advantage when working with the Arduino.

Shields are extra boards that fit directly on top of the Arduino, some examples are of Ethernet Shields, Motor Drivers, Relay, Proto Shields, LCD Shields, Sensor Shields.. there are a lot.

How can I learn?

You can learn and download resources from hundreds of websites (this one included) but the best place for information is the Arduino.cc website and Forums. Check out the Getting Started Guide linked here if you’re a beginner, this will allow you to understand some basic concepts of the Arduino.

There is much more to talk about, I haven’t even covered 1% of what the Arduino is and can be used for – Searching for Arduino projects into Google or Youtube will give you some idea of the vast array of uses for it. Or if you prefer to learn by reading then Amazon have a huge collection of electronics, microcontroller and Arduino specific books available.

I hope that’s covered some of the questions people may have about our Arduino posts! There will certainly be more on here soon.

Raspberry Pi – RISC assessment

browserJust a quick update about my RISC OS experience with the Raspberry Pi. So far I’ve got it connected to the internet and had a quick play around.

The browser that comes pre-installed is called Netsurf. It’s a nice, responsive little browser but is also a little limited. I couldn’t get any javascript to run but I don’t mind too much at the minute.

I installed Firefox through the Store app but found it to be very slow. That may be caused by the fact that I’ve only got the 256mb Pi but I did check the memory manager and it showed plenty of free RAM. Dunno.

LIRCOne thing I have managed to get installed is LIRC. I manually downloaded the package (can’t remember the link at the minute) and installed it to the SD card. There was a font problem initally but though playing around, I seem to have sorted it.

The Pi is now running IRC and I’m sat in the rather excellent #tymkrs chat room.

Now to see if I can find a VNC client…….

Running RISC OS on Raspberry Pi

RiscOSbootWhen I was at my junior school (I think they call it primary school now), we used Acorn BBCs. In fact, we used them in the infants too (mainly to play Granny’s Garden). One morning I arrived at school to find our teacher setting up a brand new computer… An Acorn Archimedes. We used these computers all through junior school and comp. Our school only had a couple of PCs and they were for using Encarta (you had to put the CD in a special little CD caddy).

Because we used the Acorns for so long, I got very used to RISC OS and loved it at the time. I now have my own Acorn A3000 computer although I’ve never managed to use it for one reason or another. I really must look into getting it running.

A3000  Anyway, here is a picture of my A3000 with my raspberry PI sat on top of it.

I’ve had my raspberry Pi for a long time and to be honest, most of the time it’s lived in a drawer. Steve uses his most days for tinkering with but mine’s been sadly neglected… Until now.

I downloaded the RISC OS image a while ago from the official raspberry pi site and it’s sat on my hard drive waiting for me to do something with it. The time is now!!

The installation was just as simple as any other OS install with the Pi. Download the image, run W32 DiskImager and pop the SD card into the Pi. While it’s booting you get a nice boot screen as the one shown above. Once it’s booted, it looks pretty much as it always did.

Apps

I’ve only had a few minutes hands-on time so far but I’m loving the nostalgia.

My plan now is to try and use RISC OS as much as possible and see how I can fit it into my daily tasks. I doubt I’ll be able to administer Windows 2012 servers from it but I’ll have a damn good go :)

What is a Raspberry PI? – A quick review.

rpiThe Raspberry PI is a miniature low cost computer that can be used for a wide range of projects and entertainment. You may have seen a lot of press around the Raspberry PI as it has had quite a lot of exposure.

It’s a great way to learn Linux computing and to dive into the world of programming – There are many resources available online such as YouTube and the Raspberry Pi Forums.

First Impressions

The first thing you’ll notice is that the RasPi comes with no case, it is a circuit board with components on, this may come as a shock if you’re used to just going out and buying a computer. Many cases of different shapes and sizes are available online, most likely from the retailer you purchased the RasPi from.

No keyboard, mouse or wireless access is provided unless you’re buying a kit that includes these items. There are 2 USB ports (Model B) on the board which you can use, or you can use a powered USB hub if you need more ports.

There is no on/off switch as soon as you plug in power it will attempt to boot. You will however need an SD Card (not provided) with an operating system already set up. There are various Linux distributions available for download from the Raspberry Pi website – as well as community developed projects such as XBMC, OpenElec for media servers.

There are currently 2 models of the Raspberry Pi – The Model A and Model B the differences are below (from the RasPI FAQ)

The Model A has 256MB RAM, one USB port and no Ethernet (network connection). The Model B has 512MB RAM, 2 USB ports and an Ethernet port.

What’s the Specification?

CPU: 700 MHz ARMv6 Processor
GPU: Broadcom VideoCore IV 250 MHz
Memory: 512MB (Model B) 256MB (Model A)
Expansion: 2x USB2 (Model B, 1x Model A) – SD Card Slot
Video Output: HDMI and Composite RCA
Audio Output: 3.5mm Jack and HDMI
Network: 10/100 Ethernet (8P8C) (Model B Only)
Size: 85.60 mm × 53.98 mm (3.370 in × 2.125 in)

What Distributions are available?

Many popular and well-known distributions are available. some of which outlined below. These are just a taste of what is available. Check out the Raspberry Pi website for more information.

  • Arch Linux
  • Raspbian OS
  • Debian
  • Gentoo
  • Fedora
  • RISC OS

What can I do with a Raspberry Pi?

The list is endless really, you can’t eat it – but the Raspberry Pi provides GPIO access for interfacing with other hardware, it can be used for learning electronics or connecting additional third-party modules. There is also an SPI interface for connecting things such as the official RasPi Camera Module.

It’s basically a Linux computer and most if not all things you can do with a regular Linux computer you can do on the Raspberry Pi. It’s convenient to just plug in to the TV or monitor and have instant access to a system, the best part is if you do manage to break the operating system it only takes minutes to fix, as the OS is stored on an external card.

Some example projects include attaching the Pi to a weather balloon, media centres, file servers, a web server, home automation, electronic projects and many, many more…

Final Thoughts

If you’re into computers or just want to learn how they work then a Raspberry Pi is for you. It’s a great educational tool for learning and for the price they cost it’s worth having a look and trying it out. Check out the Raspberry Pi website for more information and where to buy.

 

Fritzing – Open Source Electrical Design Software

fritzing-logoFritzing is an Open Source piece of software used for the design of electrical circuits. Whilst Fritzing doesn’t do circuit simulation, it does design very, very nicely. You have probably seen some of the Fritzing graphics posted on the Arduino.cc website which is what initially caught my eye.

First impressions upon loading is that it has a clean, polished layout with the interface being snappy and switching between tabs very efficient.

There are 3 layouts in which you can see your design: Breadboard, Schematic and PCB. You can switch between any one of these whilst designing, I have included screenshots of each layout below (this is the Arduino Blink LED example)

Fritzing            Fritzing5            Fritzing6

So, what’s so good about it?

The look and feel of the designs it produces look extremely professional, the PCB Layout is ideal for posting up how things should be connected and linked together and I can see myself using this on this website as well. Some other notes below:

  • High quality illustrations, including the Arduino (pictured above), breadboards and many components.
  • Open Source software, it’s completely free to download and use (check the License information first though!)
  • Missing some parts? You can create your own components and save or share them using the built-in parts editor.
  • A variety of export options, including PNG, PDF, SVG and also Etchable export formats.
  • The PCB view is useful (and cool!) for displaying your circuits.
  • There is a service to manufacturer your PCB design, however I have not used this service.

And the bad?

Well, not really any bad remarks at all, only some feature requests. How good would this be with circuit simulation? Absolutely amazing, that’s what. Plus maybe an installer so I have start menu/desktop short-cut created for me but that’s not exactly important at this stage.

This is still BETA software so you can expect the occasional bug here and there, but plenty of software updates.

More Information & Where to Download

As Fritzing is written with C++ and Qt it has support for Windows, Linux and MAC. You can also download the source code on the Fritzing website. Keep in mind that the source code of Fritzing is licensed under GNU GPL v3, the documentation and breadboard view graphics under CC Attribution-ShareALike. Please do leave credit when creating and sharing your designs online.

I haven’t been a Fritzing user for very long, so my apologies if I have missed something vital. This has got to be one of the best, free design tools available at the minute.

You can download Fritzing from fritzing.org  you won’t be disappointed. There are various tutorials, guides and FAQs on the Fritzing website.

Product Review – Peak Atlas ESR70+

esr70-1Around 80% of the faulty electronic devices I look at repairing are caused by faulty electrolytic capacitors. Sometimes you can see a physical fault with a cap (bulges on top or even leaked electrolytic fluid) but often you can’t. The only way I had to test any suspect caps was to simply replace them and test the circuit. This took ages and could end up unnecessarily costly. If only there were a better way……..

Hang on… what’s that? an ESR meter? What’s that then?

An ESR meter measures equivalent series resistance across a capacitor. Basically it’s a magic tool to tell you if your capacitor is any good or not.

I’ve wanted an ESR meter for ages but having never even used one, I didn’t know how useful it would really be….. Until I got one!!!

I got my grubby little mitts on a Peak Atlas ESR70 (or ESR plus, I’m not sure of it’s official name) and have never looked back. I’ll admit, it’s not something I use every day but it’s one of those tools that even if you only used it twice a year, it’d be worth it. In fact, I get a bit giddy every time I do get the chance to use it….. yes, I know that’s sad…

I won’t fill this post with lots of photos, I’ll just point you directly to the products web page. http://www.peakelec.co.uk/acatalog/jz_esr70.html

Anyway, back to the point. The Atlas ESR70 measures both ESR and capacitance. It’s great for checking caps to see if they are even close to the value they have written on them. I know there is a certain tolerance with the values but sometimes you find a cap that clearly isn’t performing as it should and needs to be replaced.

One feature of the ESR70 is that it can test caps in-circuit… but only in certain situations. If the cap is in series with any other caps, the reading will either be off or the meter will kindly tell you that it’s in-circuit. Nice. To be honest, I hardly test my components in circuit now because there always seems to be something that affects the result so I just whip it out and test it but the feature is there and can be useful in certain situations.

The ESR70 couldn’t be simpler to use. You turn it on and connect your capacitor. Simple. The LCD display shows the ESR value pretty much straight away whereas the capacitor value can take a few extra seconds. Once the ESR70 has read the capacitor, it makes a pleasant little “ding-ding” sound. If it finds a capacitor that is too leaky, it only makes one little “pip” sound. The beeps are especially helpful when you can’t look directly at the meter because you’re too busy holding the test probes onto a part. If you leave the unit unused for a few minutes, the meter will automatically turn itself off. This is great for people like me who forget to turn things off and then the next time I go to use it I can’t because it’s 2am and there aren’t any battery shops open……. Please tell me it’s not just me who’s experienced this….

Another useful feature is how the test leads are supplied. The unit has a crocodile clip on each wire but it can be  removed to reveal a mini banana plug. This allows you to take off the crocodile clip and connect a pair of test probes for when you need to get into a tight space. As I test most of my capacitors out of circuit, I hardly ever use this feature but it’s good to have. An extra feature on the ESR70 is that it auto-discharges capacitors before it tests them. Some other meters insist you discharge them manually first… who has time for that??

As good as this meter is, there is a little bit of work you have to do yourself (not just this ESR meter but all ESR meters). The LCD display shows you the ESR reading of the capacitor but you have to look up the result on a chart which is supplied with the ESR70. I’ve printed several of these charts, laminated them and stuck them all over the hackshed so I can read the results at a glance. Basically you find the capacitance and the voltage of the component under test and look it up on the chart. If the ESR shown is lower or very close to the value on the chart, chances are that it’s a good cap. If the results are much higher than the chart suggests, then the component is bin food.

So now you’ve googled ESR meters and found a nice man in China who will sell you one at a seemingly great price on aliexpress. Why shouldn’t you buy that one instead? Well, for the same reason you would rather use a fluke multimeter instead of the one that came free in a box of cornflakes. (Slight exaggeration but you get my drift). I personally wouldn’t want to rely on a piece of test equipment that was thrown together for a few pence and will probably fail within a few months.

Peak Electronic Design Ltd is a British company. It’s Managing Director is a chap called Jeremy Siddons and he’s also the lead engineer within his company. I’ve spoken to him before and it’s immediately obvious that this is a guy who knows his product inside out (he did design it) but more than that, he cares. He cares about his products, his company and most of all, he cares about his customers. If you follow his Twitter feed (@peakatlas), you’ll see his conversations with his customers. It really is important to me that a company cares about it’s customers. Too many companies out there don’t give a toss, once you’ve spent your money, you can leave them alone. Peak isn’t one of those companies.

D-Link is but that’s another story……

Anyway, do yourself a favour – go and buy one. I promise it’ll change your life.

No, I’m not affiliated with Peak Electronic Design in any way and no, I haven’t been paid or asked to do this review. I’ve done it because I firmly believe in credit where credit is due.

 

Arduino – sorting array integers with a bubble sort algorithm

As it happens, I needed to sort an array of integers in ascending order and also find the minimum and maximum number from the array on my Arduino. I decided to knock up a quick bubble sorting function which you can find below.

Bubble sorting is probably one of the easiest and quickest (to write, not actually sort!) algorithms to produce in C. It works by iterating through the array of values comparing pairs and swapping them around if need be, it then performs the same action again until no swapping is needed. You can read more on the Bubble Sorting algorithm by clicking here.

The above Arduino sketch has debug Serial output which should look like the following one uploaded:

bubble

This code isn’t limited to the Arduino, there are no special function requirements needed and should work in any C based application. The only thing that you may want to change is finding the size of the array instead of having it static however I did not need this as I knew how many elements I needed.

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