Dan Welchman Productions

Projects, Interests & Research (both work and play!)

My Brewery
Littleport Judo

Engineering! - a lifelong passion

As a kid, I wanted to be an Engineer. Not anything else. Not even an astronaut or rock-star or prime-minister. Forty something years later, it's STILL the only thing I want to do for a living.

I studied Mechanical Engineering at university, but on graduation came to Cambridge to write Engineering software. Software attracted me because of the speed at which you can invent something, prove it, and turn it into a product that works. I've been in Cambridge ever since, working first in the CAD industry, then in the GIS industry, in both core and application development. Latterly I've also been involved in tool development and process improvement, particularly in the area of test automation. In the last few years I've been working in the Semiconductor industry on wireless and audio embedded systems. This has re-kindled a long standing interest in Electronics resulting in some very entertaining home mechatronic projects involving microcontrollers, robots and ROVs.

Electronics - we've never had it so good!

Having been an electronics hobbyist in my youth, coming "back" to electronics in the 21st century is a real treat! Whereas the op-amp was my "universal component" in the 1970s, now it's the microcontroller: fantastically powerful, fantastically cheap, and fantastically easy to use - you simply program it in good old C. I'm constantly amazed by the range of components available, how cheap they are, and how quickly you can get hold of them. Likewise, it's so easy to get access to any information you need thanks to the internet. If you come across a mysterious component during a tear-down it's normally identified after a couple of minutes googling. Similarly, any confusion about the principles can often be resolved by viewing some of the excellent YouTube vids from the likes of Jack Ganssle and Dave Jones.

Below are a few photos of current projects. The large "robot base" is powered by two 24v scooter motors. It'll do about 7mph and can carry 40kg. It's designed to have multiple different superstuctures bolted to it and supply them with power at a range of voltages. An Arduino "micro" reads incoming radio control pulses using hardware interrupts and generates PWM signals to drive the motors while monitoring current etc and generally keeping an eye on things.

Test Automation

I have been a Test Automation enthusiast for many years. It started when I worked in the GIS industry and we had a bit of a crisis with the testing workload on our many and varied application products. In 2010 I wrote a record / playback tool, MATT, which was somewhat like Selenium but for GIS applications rather than web applications. MATT featured "precision assertions" to detect subtle engineering-specific error states while avoiding false alarms. It was used to replace bulk manual testing, and to replace some brittle older legacy automated tests. It was fast enough to be deployed on code check-in by the Agile teams who use it, alongside their unit tests. We also used it for defect description, as a fast and unambiguous way of re-creating the circumstances of a bug.

Looking forward, I reckon record/playback technology is also going to be productive beyond the test lab for things like training, demos and documentation production/localisation. These sequences could still function as tests of course, giving extra coverage and checking that materials are up to date and not broken. Of course, the trick to achieving multi-use like this is to ensure that the recorded sequences are very robust and portable. Not easy! -but it can be done!

If you're working on similar ideas (whether commercially or in research) then do get in touch for a chat!


I wrote MouseTrial for my son Kit, who has autism. It's a system of exercises using animations to reward the player when they click on the correct item from an array. MouseTrial is now in use by hundreds of Families round the world. It can be played directly online or downloaded and played offline. License keys are sold round the clock from my online shop. Although extremely easy to get started with, MouseTrial is highly adjustable to cope with the enormously varied abilities and needs of children on the Autistic Spectrum. The MouseTrial web site is one of the top-ranking resources for autism, and there's an Android App version of it available too.

Why not HAVE A GO with the MouseTrial games? there are well over 100 animations to be "won", some of which may give you a bit of a chuckle. It can be rather addictive!

Autism software database

My autism software database is a free resource for parents and professionals listing all kinds of software for autism treatment. It's a PHP / mySQL application which publishers can log in to and update their own blurbs, add new products, and so on. The database continues to expand as I get a steady stream of suggestions for new entries from the public. I also have a special purpose web-crawler (written in Java) which unearths many more interesting autism-related sites.

Book Publishing

I publish the occasional book.

I wrote, illustrated and published "The Power" to explain the glories of exponentiation. It was fun. My books are set in the fictional Captain Astounding's Nightclub in Fulchester. An odd venue, but one that provides many useful examples. The Power is currently out of print but you can still get it in pdf form (see below) and it's FREE! Note: it's simply a pdf file of the print version, not a true e-book, so it may be easier to print off and read rather than use on-screen. It doesn't have an interactive table of contents, references etc. Also, it's about 30MB so allow a little time for it to download

Captain Astounding's Nightclub "The Power" download... the_power.pdf

A second volume in the series (on probability and combinatorics) is roughly half written and about three-quarters illustrated. Other projects have taken precendence but I hope to get back to it and finish it one day!

Animation and Artwork

I like to do my own illustrations, cartoons, and animations for my works, both online and off. I get the same pleasure from producing a new animation as I do from writing a new piece of software. Besides, the prices are so reasonable! The animation opposite is "spider" from the animals module in MouseTrial. My other son, Harry, helps me to come up with ideas for the animations.

Beer Brewing

I have been brewing beer since the 1970s. I brew "from the grain", ie starting out with a big sack of malt rather than a kit or can of extract. These days I nearly always use the ancient "Parti-Gyle" system. This is where you use the same batch of malt to produce several different beers of diminishing strengths rather than watering it down (sparging) to produce a single large brew. It's an efficient technique and allows production of two (or more) contrasting beers in a single session. I'm also experimenting with making my own hop-extracts so that I can separate out the wonderful flowery and spicy components of the hop flavour and smell and add these to beers independently of their bitterness. Until recently I simply brewed up in the kitchen, typically making a right mess and causing extensive domestic dis-harmony. But all that has changed with the completion of my purpose-built Dream Brewery which is a marvel of sophistication. Do take a quick look if you're into brewing!


In 2005 we discovered that there was a Judo club in Littleport. My son Harry and I went along to have a go, absolutely loved it, and have been doing it ever since! Now I'm a first dan competetive black-belt and have recently passed my level 1 coaching assessment. I have served as the club welfare officer for many years, but will be switching to the junior coaching role shortly (as soon as I gain my sports first-aid certificate!). The club trains every Tuesday night so please free to come along whatever level you've reached. At the time of writing we have players ranging from complete beginners to nationally ranked fighters.