Organic farming and the consumption of organic food creates a positive feedback cycle – healthier food, cleaner planet, happier people. The cycle goes something like this:

• Organic farming techniques result in improved soil quality and fewer chemicals entering into the environment.
  
• Improved soil quality results in better water retention, reduced run–off and a higher nutrient content.
• Reduced run–off along with reduced chemical usage results in cleaner water systems.
  
• Reduced pesticide usage results in an increase in biodiversity and strengthened eco–systems.
• The reduced chemical input means less energy is being spent to product petro–chemical based fertilizers.
• Reduced energy and fossil fuel consumption means reduced emissions and therefore cleaner air.
• We get healthier food, cleaner water and cleaner air resulting in healthier, happier people.
  
• When people choose organic products over the alternatives it encourages farmers to choose organic methods, therefore strengthening the positive cycle.

Compare this with genetically modified crops:

• GM crops encourage the use of herbicides (like Monsanto's Round–up ready crops).
• Farmers cannot propogate their crops (which hands over food security to large corporations) or develop seed varieties suited to their soil and environment.
  
• Conventional methods require the addition of chemical fertilisers to maintain soil quaility.
• Exclusive use of chemical fertilisers results in a narrow spectrum of nutrients in the soil.
• Fertilizers, herbicides and pesticides run–off and pollute the water system.
• Pesticides result in the death of beneficial birds and bugs.
• More energy and fossil fuels are spent on the production of chemical fertilisers, herbicides and pesticides, resulting in more emmissions and dirtier air.
• Potential health concerns exist.
  
• Lower quality food as well as dirtier air and water – more unhealthy and unhappy people.
  

There are two main arguments that I have encountered against organic farming techniques: yield and cost. Many people believe that yields are lower with organic techniques while they actually average out to be the same as, or higher than conventional farming over the long term. In some cases, particularly in Africa, organic farming yields are much higher than conventional farming (this is partially due to the reduced input costs).

Cost is a factor of supply and demand, but is also influenced by organic certification costs which are high and ongoing. Small organic farmers are often unable to afford full organic certification, but their non–certified organic goods may be available at better prices through farmers markets, co–ops and CSAs. If costs is an issue, but you want to reduce your pesticide intake, then you can focus on choosing organic varieties of the top offending foods on this list.

If you are in Cape Town or the surrounding areas you can get reasonably priced organic produce from fully certified, as well as non–certified, organic farmers via The Ethical Co–Op.

Photo courtesy of Jennifer Dickert, licensed under a creative commons license.

What you do matters. What you do each day matters. The decisions that you make are important.

Sometimes we forget that our role, our decisions and our actions play an important part in the world around us. It is especially easy to forget when we are faced with overwhelming circumstances or events. Many people who care about the environment feel overwhelmed by the scale of the challenges we face. In that same way many businesses and households are reeling in the face of a global financial crisis.

It is so easy to go into a state of stasis – doing nothing, or just reacting to our immediate challenges. The worst thing to do is nothing. Reacting may mean reducing your budget and cutting out excess spending. It may be reducing your environmental impact by buying less stuff. The problem is that reacting is defensive, like pulling your hand away from a hot stove. If you are always defending you are never going anywhere and standing still is a bad idea in a rapidly changing world.

Responding is better, initiating is best. When we respond we take positive actions, actions which improve our lives rather than deprive them. Environmentalists often go wrong by focussing on what we need to take away rather than on how we can improve and benefit our lives right now, but we know from dieting that deprivation is a temporary solution which leads to overindulgence. Respond by adding positive actions.

When we initiate we go beyond ourselves. We push beyond our own personal boundaries and lead people to new places. Creating new innovative products or processes in a slow market is initiating. Starting a recycling programme within your community (your street or neighbourhood) is initiating. Everyone has the opportunity to be a leader, whether you are a young engineer trying to push new ideas into a big company, or a housewife who wants to create a better life for your family. You may lead just a few people, or many – what matters is that you take action. We need you to lead.

Taking action is difficult and requires consistency and effort, so I would like to leave you with this story about Jerry Seinfeld.

Jerry says that to be a better comic you have to create better jokes, and to create better jokes you have to write everyday. He puts a big calendar on a prominent wall and every day that he fulfills his task of writing a new joke he gets to put a big red cross on the calendar. After a few days of doing this consitently you will have a chain. Jerry says, "Your only job is to not break the chain. Don't break the chain."

Innovate, be consistent, keep taking action, what you do matters. We need you to lead.

Kudos to Seth Godin and his book Tribes which inspired this post. You can get a free audio version of Tribes. Read the book or listen to the audio version – it is a valuable investment of your time and effort.

Electronic design automation tools like OrCAD, PADS and Altium Designer are part of an electronic engineer's day–to–day life. We need these tools to tell the story of our designs – to lay out the concepts in a symbolic form in the schematics and a physical representation in the PCB files (and much more).

Most companies use expensive commercial tools (like those mentioned above) which offer many features and benefits, but these do have some disadvantages. The biggest hurdle for smaller companies is cost, which makes it difficult to get going – you cannot earn money to pay for the tools without using the tools, which is a vicious circle. Another big disadvantage of commercial tools is their closed nature – file structures are closed and it is difficult to add custom features to the tools. Further to this, if you need improvements or bug fixes you may have to wait a long time before these become available, especially if you are a small customer. In some cases companies are bought out, forcing you to change software and go through a whole new learning curve. To phrase it differently: small users have little say in the direction of the development of the tools.

The big advantages of commercial tools are the multitude of features (if you need them), and commercial support.

When I had to choose an EDA tool suite my (non–existent) budget was the biggest deciding factor and I decided to start using an open source set of EDA tools, gEDA. I have been using gEDA since the middle of 2007, and have completed a number of projects with it. At first I just did my schematic layout with gschem and outsourced the PCB layout which was done in PCAD. Recently I completed some PCBs for a project which where done with gEDA's PCB programme (this was my first entirely gEDA project).

I initially made my choice based on the free price of gEDA, but as I used it and learned more about how the suite works as a whole I discovered that there are far more compelling reasons to choose an open source EDA suite over a closed one.

The open nature of both the file structure and the source code is an incredibly powerful tool for productivity. Think about this simple example: the creation of PCB footprints (or land patterns). Creating footprints is often a long and arduous process which involves graphically drawing out exactly what it should look like and vetting the details. Each subtle variation on the footprint requires more time drawing and checking. The well documented open file format and excellent documentation on the creation of footprints for PCB allows scripts to be written to automate the creation of footprints resulting in a significant time saving. Similar scripts are also available for schematic symbol creation. These are really simple examples of what can be accomplished when the file structure and code is open and documented – far more exciting things can be done, just about anything you can think of!

gEDA is also blessed with a very active support and development community, which operates mainly through the gEDA mailing lists and the gEDA wiki (which provides excellent documentation). I have asked many questions and received quick and helpful responses. How long did your last support request with a commercial company take to be resolved?

I also believe that using an open source EDA suite provides you with more stability and control over the future of your tool chain. If a large commercial tool set is either bought out, or decides to change how it works significantly you have little choice but to embrace that change, whatever the cost or learning implications are. An open source EDA tool provides you with a never ending upgrade path for the future, as well as access to the direction the tool takes. This stability comes with a responsibility to be a part of a community, rather than just a consumer. By becoming a part of the community you create a mutualistic relationship where everyone benefits.

gEDA (or other open source EDA tools) may not be suitable for everyone, or for every project, but there are a large number of projects that can be supported by these flexible tools. Using gEDA does require a shift in the way you work, but so does any other change to your EDA tool chain. Putting in the effort to learn how to use gEDA is certainly worth it and offers the opportunity for large productivity leaps. These productivity leaps are important, as they ensure that engineers spend more time creating, designing and solving problems, rather than wasting hours on repetitive tasks. I am using it exclusively to provide solutions to my customers, and you should take a closer look at it too.

Here is a list of open projects created with gEDA. One of the most impressive open hardware projects that I have seen which uses gEDA is the Free Telephony Project, which not only shows the quality of these tools, but also the magnitude of what can be achieved with open hardware development.

Please note that files and projects created by you are entirely yours and can be used for commercial purposes without any ramifications. The projects noted above have chosen to share their work under open licenses.

There are no up–to–date Windows binaries available for gschem and I found that the PCB binaries were really slow. I run the entire suite on Cygwin. Here are the install instructions for gEDA on Cygwin. I also recommend compiling PCB on Cygwin for significantly improved performance.

I posted my thoughts on creating my first PCB with PCB to the gEDA mailing list – this may give you some ideas of initial hurdles and ideas that you will need to get through.

What I learned at the Natural & Organic Expo

I visited the Natural & Organic Expo last weekend and learned a few things.

1. Polystyrene can be and is being recycled in Cape Town.
   

   From the reading that I have done I thought that polystyrene was expensive and inefficient to recycle, mainly due to the problems associated with transporting such a light plastic, but polystyrene is actually collected, melted into ingots and recycled into picture frames, stationery, cornices, skirting boards, hangers and seedling trays. In Cape Town EPS Reclaim in Montague Gardens collects and smelts polystyrene. Find your nearest polystyrene drop off point.

2. There is clearly a big demand for natural cleaning products.
   

   I was amazed at how many different natural, organic and bio–degradable household cleaning products were on show. The demand and acceptance of these products is growing not just for environmental reasons, but also due to health concerns such as allergic reactions.

3. Oxi-degradable plastics are creating headaches for recyclers.
   

   I have written about oxi–degradable plastics before. It is important to realise that oxi–degradable plastic is very different from bio–degradable plastic. Companies like Green Home make bio–degradable plastic from plant sources (in their case bagasse, a byproduct of the sugar industry), while oxi–degradable plastics are normal plastic (like polyethylene) with the addition of a metal salt which causes them to break down over time. In South Africa oxi–degradable plastics have been used mainly for fruit and bread bags. The problem with these types of plastics is that they are indistinguishable from normal plastics and it is difficult to know how far the degradation process has progressed. Oxi–degradable bags pollute the recycling stream and result in a poor quality end product.


4. Bio–degradable plastics require education and infrastructure.
   

   Bio–degradable plastic products made from sustainable sources (such as bagasse, mentioned above) may provide a viable alternative to plastic in some cases. It is important that they are manufactured from sources other than food crops (plastic from corn is unsustainable). A problem that needs to be addressed (and is being addressed by manufacturers such as Green Home) is how to manage the waste from these products. Simply dumping bio–degradable plastic into a landfill is undesirable. Bio–degradable plastics will not degrade in a landfill, which means effective collection and composting needs to take place. Consumers can compost these packages at home, but without education it is unlikely that this will happen. Education, collection and composting infrastructure is an important aspect of bio–degradable plastic.

5. Egg yolks contain colourant.
   

   Pick 'n Pay is selling a new range of indigenous free range eggs, and one of the marketing points is "No yolk colourants." Yolk colourants? It turns out that chicken feed is often supplemented to increase its carotenoid content to obtain a more consistent colour yolk. The supplements used appear to be natural or "nature identical" such as lutein and canthaxanthin.

It was good to meet new people, get exposed to a few new ideas and to find new sources of organic and environmentally aware products. If you are in Cape Town and the surrounding area then make a point to go next year.

Light and heavy symbols

This post is aimed at electronic engineers working with electronic design automation (EDA) packages.

As an electronic engineer you have probably been through it. It all starts simply and clearly. You need to draw a schematic; so you make some symbols, attach some attributes to them and get going. Then you draw some footprints for the PCB layout and make sure the correct footprint names are attached to the components you have created. The boards go the PCB manufacturer and you use a simple spreadsheet to manage the bill of materials (BOM). Everything goes nice and smoothly – you are happy.

Then another project comes along – a bigger one with more engineers working on it. You carry on like you have before, explaining to people how to create new components and footprints and how to make sure the part numbers are correct. It all seems to be going well. The PCBs and components arrive, but something is not quite right. One of the components (an expensive one!) is the wrong part, and another component does not fit onto the PCB footprint correctly (even though there is another component with the same footprint that does fit correctly). What went wrong?

Eventually with more projects and more people managing the component library becomes a full time job for someone, and getting a new component approved is a lengthy process for engineers. Let's not even talk about managing the now massive stock and BOM spreadsheet which keeps you awake at night. The quick process you started with has become a slow moving, time consuming beast. We need to find a way to kill that beast so that engineers can spend more time creating solutions to problems, and less time on administration.

There are two ways to handles components. We can either have "heavy" symbols, or "light" symbols. First a few definitions so that we are all talking the same language.

component	:	an actual physical part.
symbol	:	a diagram depicting a component which is placed in a schematic drawing.
footprint	:	the physical layout of a component on a PCB.

A heavy symbol has all of its attributes, such as part name, value, voltage, tolerance, footprint, ordering number, etc. specified in the symbol library. A light symbol has no attributes specified in the library and all attributes are added at a schematic level.

There are some obvious flaws with each approach. A heavy symbol library will quickly grow in size – just think about having a symbol defined for each different opamp or resistor that is used. The graphical representation of an opamp is generic to a number of different parts, but now duplicates are created for each component. If a fault does creep into the library it can result in a number of different symbols needing to be fixed.

With a light symbol library all the attributes are added to the schematic. Maintaining the symbols is easy (because there are fewer), but ensuring that the correct attribute information is added can lead to errors (each time data is manually copied or entered there is the potential for an error).

There are also some obvious advantages. A heavy symbol immediately makes a lot of information available in the schematic which can be passed on to other tools, such as the footprint to the PCB layout package, or the part number to the BOM. A light symbol allows for information to be drawn from multiple sources, and the schematic can be updated without having to propagate the changes back into the library.

Here is a brief summary of the feature of each type of symbol.

Heavy symbols:

• Data duplication,
• Errors requires changes to numerous symbols,
  
• Require a librarian to maintain symbol library sanity,
• Single source of information.

Light symbols:

• No data duplication,
• Errors can be fixed at schematic level, or only affect a single symbol,
• Allows multiple data sources for component information,
• Requires addition of attributes at schematic level.

If you remember that I am against information duplication, then you should have guessed that I am in favour of light symbols.

The "light" and "heavy" nomenclature arose out of discussions on the gEDA mailing list. The gEDA wiki has a brief summary, and the two threads which I think are the most relevant are "Light vs. Heavy gschem symbols?" and "Heavy symbols and such."