Monday 7 December 2015

Christmas Cheer with a PICmas Tree


This was a beast of a project, but I got it working and somehow fit it into one article just in time for the holidays. I've only been writing since August and this is my most ambitious project yet!

Don't forget to check out my latest PIC n' MIX article in Everday Practical Electronics, where I will show you how to build your own PICmas Tree, using the LPLC board from MJH Designs. I use 68 LEDs to make a festive looking LED tree that sparkles and glows for the festive season!

You can buy it in PDF format online at http://www.epemag.com/buy-epe-online.html or you can buy it off from the shelf in your nearest newsagents.

Happy Christmas to one and all and a Very Merry New Year!

Here's a tiny sneak peek of the PICmas Tree, see the magazine for a better picture and details of how to make your own.


Friday 6 November 2015

How to Pick a PIC


Don't forget to check out my latest PIC n' MIX article in Everday Practical Electronics, where I cover how to choose a PIC microcontroller from over 1000 different PICs available on the market. I also talk about the hotly debated 8-bit versus 16-bit and 32-bit and their specific place in the world today.

You can buy it in PDF format online at http://www.epemag.com/buy-epe-online.html
Or you can buy it off from the shelf in your nearest newsagents.

Wednesday 28 October 2015

DIY Digital Oscilloscope Kit

So, I've been buying a load of equipment from Bang Good. It really is a great site, with a lot of electronic equipment at a great price.

My latest piece of equipment is my DIY Oscilloscope. As most hobbyists know, oscilloscopes can be expensive to purchase, but this little beauty comes in around $24. Like the DIY Adjustable Voltage Power Supply in my last blog post, it comes unassembled. Well except for the 48 pin Cortex M3 processor from ST Micro Electronics, which would be difficult for most hobbyists. All the other components are straightforward enough to attach and connect to the right place. There is less documentation with this device than there is in the DIY Power Supply. This is slightly annoying when trying to figure out what components go where. There's also a lot more components on the board, so it will take longer to build. 

The device itself comes with a 2.4" TFT screen. Unfortunately it's not a touch screen interface and the 4 buttons have to be used to navigate the settings on the screen, which is a little awkward to use. It also comes with a BNC connector cable with crocodile clips. There are also 3 switches to select between GND/AC/DC coupling, voltage divisions and amplitude magnification. It does not come with it's own power supply and the 9V input must be supplied externally. It also does not come with a case, which would have been nice. 

It is fun to build these devices, although not trivial, it's even better when they can be used as a tool to verify all of our other projects. It's not a full on professional Oscilloscope, but it does have quite a number of useful features. There's Automatic and Normal sampling as well as the single shot. It can capture on either rising or falling edges. We can change the trigger level as well and change time division from 500s down to 10us. I have to admit anything above 1s is a little excessive for capturing on a scope of this type.

You can see the working oscilloscope in the 2nd attached photo, powered by the previously mentioned DIY Voltage Adjustable Power Supply. 

If anyone else has ever bought this and had issues with it, comment below and let me know what you think or if there's anything else you would change about it. 

If you're looking to purchase this kit, check out the following link at Bang Good.com: DIY Digital Oscilloscope Kit

Sunday 25 October 2015

DIY LM317 Adjustable Voltage Power Supply Board Learning Kit With Case

I recently bought the LM317 Adjustable Voltage Power Supply Board from Bang Good.com. For about $12, you can't go wrong. Bang Good is a Chinese distributor based in Guangzhou, China. The shipping was cheap enough as well, although you'll be waiting up 4-5 weeks to receive it. If you're not in a rush, then it really is a cost saving. 

The Power Supply comes with an adjustable signal generator output, that provides a pulsed signal. It also comes with an onboard buzzer and a number of LED's that indicate output voltage levels. The most useful part is the single piece voltmeter. It illuminates to tell you the output voltage, which is very useful to know before you attach it to anything else. 
All the components come not populated on the board and you have to be assembled yourself. So you'll need a soldering iron and some solder. I also recommend a decent flux pen as well; it ensures a decent connection and reduces dirt. The kit comes with a detailed diagram of where to place each component. I will admit you will also need a multimeter as some of the resistors are not labelled. Unless of course, you can read the colour band markings. 
Once built, it's a solid little power supply and I have used it for many DIY projects. The output voltage ranges from 1.25V to 12V and is continuously adjustable.
As you can see in the attached photos, we see the board as it arrives, after it's built and an updated photo too. In the updated version of the board, I used a 2A, 250VAC switch on the secondary side of the transformer to enable me to turn on and off the power supply when I want, without having to unplug the device all the time. I'm not sure if you can see it fully, but I've also replaced the standard 2 pin EU plug they supply with an old UK, BS1363 plug I had lying around. I had to insert a connector block for the live and main and I connected the earth to the underside of the transformer for safety purposes. I like to add extra protection if needed. I could connect the earth to the ground on the power supply board in order to remove my floating output on the power supply, but this proves problematic with various projects. It also a potential cause of electric shock based on whatever projects I connect it to. For example, when connecting it to systems that use the floating reference to increase the voltage. By connecting the ground to Earth, I would remove the possibility of doing this.


All in all, this is a very useful product. It's small and to the point. I really like the clear perspex box they supply with it and I'm also a fan of how it screws together using T-shape cutouts. There's little else that I would add except for what I've already mentioned. Well maybe I'd increase the height of the potentiometer for adjusting the signal generator output, which is a pain to try and get at. You'll need a smaller than 4.5mm Phillips head screwdriver to get at it.

If anyone else has ever bought this and had issues with it, comment below and let me know what you think or if there's anything else you would change about it. 

If you're looking to purchase this kit, check out the following link at Bang Good.com: DIY LM317 Adjustable Votlage Power Supply

Friday 12 June 2015

Radionics Designspark Review


I've been meaning to write an article regarding Radionics' Schematic Capture and PCB Layout tool: Designspark.

Designspark is a free EDA (Electronics Design Automation) tool, which can be used by professional electronic engineers to hobbyists and students. You have to register to access all the features of the package, which is only a minor disadvantage. Unfortunately you have to do this every time you upgrade to the latest version.

When I started working in Ircona back in 2006, I got used to Cadence's Allegro HDL package. This is a top end software package with many advanced features. Allegro HDL is a powerful tool and easily allows the importing from other EDA design packages like OrCad. However I found it large and cumbersome when it came to smaller designs and I went in search of other design tools. We only had the one PCB Layout licence in the company and I never got an opportunity to try it out. However, I can compare the schematic capture side of things and detail my experiences in PCB Layout.

I've been using Designspark in Coolpower Products for the last two years. I've seen quite a few changes from version 5.0 of the software to the current version 7.0. I have personally designed and built either by hand or machine assembled through manufacturers more than 10 different designs of varying complexity from low voltage DC double sided 20mm x 40mm boards to 200mm x 100mm 4 layer boards to High Voltage AC (~240VAC @ 16A) 500mm x 400mm 2oz Copper designs, which are all now viable and functioning products. The tool may not be the best of the best, but it is great for what you get.


Schematic Capture


The schematic capture is straight forward enough. Select a component from the add component button (conveniently shaped like a transistor) and you can access all your component libraries.

Libraries

Libraries are bread and butter of schematic capture and layout. These contain all your details for components and layout files. The libraries in Designspark are split up into three seperate sections: Schematic Symbols, PCB Symbols, Components and 3D View. The Components join the Schematic Symbols and the PCB Symbols together to give a unique component to be placed. To create a new component, first you must create a schematic symbol, for example a square with 4 connections on the left and 4 on the right. As per most schematic design, the standard is to keep all inputs on the left, outputs on the right, power to the device on top and ground on the bottom. 
Once this has been completed, you must create the PCB symbol. The PCB symbol should match the specific part you want in your design. A lot of the time, there is a standard PCB footprint that can be used and re-used, for example Fairchild's Wide SOIC-8 on the left hand side. This is a standard package size for small I2C devices like EEPROMS, RTC and other sensors.
Once the PCB symbol has been created, the Component can then be created joining these two parts together, linking the schematic with the PCB Layout. 
At first I used Designsparks own libraries, but upon my first PCB, I found a lot of issues with pad sizes and incorrect connections on some of the devices. So I proceeded to create all my own libraries. Now this is not an ideal option and takes a lot more time, but it means that I have individually created each and every part and can prove each one is correct. This is advantageous in the long run if you want to use this tool professionally and want to reduce risks to layout.




PCB Layout

So you've created your schematic and that;s great on paper, but we want to make it into something real now. The PCB Layout tool comes included as part of the package and your schematic becomes a reality just by clicking "Translate to PCB". This opens up a very easy to use wizard, which guides you through some of the basic setup needed to get you started on the layout of your design. Unfortunately making a mess up at this point, is only really easily fixed by starting all over again, for example choosing 2 layer board, when you need a 4 layer board.


Autorouter
This is a standard autorouter, there's nothing special about it. It can be handy for trying to get an idea of the routing difficulty, but in the end, I prefer to hand route each and every signal. This may be more time consuming, but it increases my confidence in every signal.

File Outputs

The most important thing any designer or hobbyist wants, which Designspark easily provides are the following:
  1. Gerber Files (most common format is RS-274X or the older RS-274D)
  2. Excellon Drill Files
  3. BOM Files
  4. Component Positions (TXT and CSV Format)
These are the basic files that will get you your PCB laid out, components purchased and assembled through pick and place manufacturing process,

There are plenty of other file outputs that are very useful as well: Generic Netlist, Schematic PCB/Check, Dangling Tracks, Component Height and many more.

I would recommend using any Gerber viewer to verify your gerber files before sending to manufacturing. Gerbv is very popular.

Quick Note on the latest Designspark 7, they changed the output format of the Excellon Drill files from trailing zeros to leading zeros. I found this causes a problem with the scale of drill files, which affects 50% of the gerber viewers out there. Just open the .drl file and change the following:
METRIC or METRIC, TZ
to 
METRIC,LZ,000.000

Revision Control System

Version Control is very useful for any engineer, hobbyist or student. The ability to not only save and improve on your design, but to be able to verify changes between any versions and to be able to undo changes from a repository are incredibly useful. With the ability to store large amounts online, it is a great idea to back up your design on any online repository .
I've proven Designspark works well in a repository situation. I have separate repositories for my libraries and each design. This allows me to backup my designs as well as allow any approved user to download and use my design if they so wish. 

I've found BitBucket is very useful for this as it keeps any work online private by default, where as Git is public by default and you have to pay to keep it private

Conclusion

So I've discussed a number of points about Designspark and it's uses. I've written up a few pros and cons below, which can give you a quick run down of the program itself.

PROS:

  1. Obviously it's free for everyone. No worrying about licencing.
  2. The PCB Layout package comes immediately with the tool and is immediately ready to go.
  3. There's no awkward setup upon installation to get it just to work (obviously you can adjust it to your preferences if you so wish).
  4. Modelsource, there's a wide variety of libraries (schematics and layout) that come with the tool already that link to Radionics website, which easily gives you pricing and availability.
  5. The Tech support from Radionics for the tool are actually very quick and helpful. Although a little arrogant to make the necessary changes to fix the problem in the first place.
  6. Components in Libraries can be used to store all useful information on part, most importantly the manufacturer name and manufacturer order number for BOM generation.
  7. I found it very easy to get it up and running and start designing immediately compared to other CAD tools. 
  8. There are numerous step by step wizards, which guide you through symbol creation, pcb translation and others. This saves time by using commonly used variables instead of hand drawing each time.
  9. You can use 3D View to view your design in a 3 Dimensional view and get an idea of how close components are and ease of building the board yourself (not covered in this review)


CONS:

  1. Have to re-register everytime a new version is released. Older versions are not removed.
  2. No offpages in schematic capture, difficult to keep track of where signals connect to on other pages. Can become very annoying as design grows.
  3. Modelsource, I know I've put this as an advantage above, but the disadvantage here lies in the trust that the libraries and parts are correct. But this can be ignored and you can create all of your own symbols by hand.
  4. The creation of schematic symbols and pcb symbols can be a little quirky and often lines don't meet up correctly due to grid alignment.
  5. There are plenty of little bugs and glitches in the program, but they are gradually getting weeded out over time.
  6. Solder Resist mask is not automatically added in PCB generation.
  7. Spacings are restricted to only Tracks, Pads, Vias, Shapes, Text and Boards. This makes it very awkward when you need specific design rules between specific signals and specific shapes.

Here's a list of interesting and useful website for your own designs:
  • http://www.4pcb.com/gerber-file-guidelines.html
  • https://www.apcircuits.com/resources/information/gerber_data.html



Wednesday 27 May 2015

573 days and I'm back to talk about my future in blogging!

573 Days and I'm back with a bang!


It feels like it has been a lot longer since I updated this blog. I've been so busy over the last few years. Since I got engaged back in 2012, it's been go-go-go! Since then, we've saved and saved for the wedding of our dreams in Druids Glen Hotel out in Newtownmountkennedy, Co. Wicklow. 

We've bathed in the Thermal Baths in Budapest, Hungary, gone Snowboarding and Skiing in the French Alps in Tignes as well as toured the beautiful landscapes of Sri Lanka and sat on a beach in the Maldives drinking cocktails.

So, I want to give my blog more life, I want to write more about my adventures travelling to the adventures in gardening. This blog was originally a way for me to capture my experiences with no clear objective or goal. So I've decided to increase and focus the topics I will be writing about to three main topics: Technology and Gadgets, Holidays and Travelling and Gardening.

Technology and Gadgets:

In the last year, I have played with many new gadgets, each of which I want to talk about here in separate posts. From Quadrocopters, Tesla Coils, 3D Printers to the Oculus Rift DK2, WiFi/Bluetooth LED bulbs and various Kickstarter products.
 


Here are just a few topics I want to talk about in the next while, with regards, technology and gadgets.
    • WiFi versus Bluetooth LED Lightbulbs
    • Oculus Rift DK2
    • XC5 Quadrocopters
    • Mbient Labs Metawear, wearable sensor and motion platform
    • Prusa 3D Printer
    • Teslatronix Tesla Coil
    • Schematic Design in Designspark
    • Layout Design in Designspark
    • Releasing PCB design to manufacturing
    • Microchip PIC Programming
    • Manufacturing Testing for Volume Production


    Holidays and Travel:



    Another topic I would like to cover from time to time is the wonderful adventures myself and my beautiful wife embark on. From the beautiful New York CafĂ© on the left to the beautiful snow white landscapes of the French Alps in Tignes. 

    The following is a list of the places I'd like to cover:

    Tignes, France
    Budapest, Hungary
    New York, USA
    Tignes, France
    Sri Lanka
    The Maldives (Kuramathi)
    Agadir, Morroco


    Gardening:

     Since I've become a home owner, I've developed an unexpected and weird interest in gardening. The photo on the left, shows what the garden was like when we moved in. It was a mess, full of Pyracantha (evil thorn bush, red berries and good for keeping cats out). I rented a wood chipper, borrowed saws, pickaxes and shovels to attack this garden like a fat kid on cake.


    I don't know much about gardening and I'm completely making it up as I go along.I grab ideas from Pinterest and various random sites with random ideas.

    We decided to get an extension on the kitchen, which was a great idea for the house, it is beautiful. Unfortunately it wasn't so good for my little garden. It's been in a terrible state since November.

    So for the next while, I'll be rebuilding it back up again and I hope to cover some small topics in the future as I progress.

    1m x 1m Vegetable planter
    Various Fruits and Vegetables
    Flowers
    Building outdoor shelves
    My Man-Shed

    So, hopefully this post sets the standard moving forward that I need to keep to on a week by week basis.