Development and Prototyping

It's been a while since I wrote about our  project to design an Arduino-controlled Electronic Load Controller (ELC) but we've made some good progress so it's about time to give you an update! For a reminder of what the project's about take a look at my post from September introducing ELCs.

Ben and Rory and some of their colleagues at Strathclyde University in the UK have been working hard on the project, and we have been able to start construction of the "ELC V2+" here. The work at Strathclyde has involved students in their EWB-UK student branch and also 5th year undergraduate students who are contributing to the project as part of their masters project. The 5th year project includes some broader, forward-thinking  into how these systems could work as an intelligent mini-grid of several generators, and how the work could also be relevant for other parts of the world, against the backdrop of the Sustainable Development Goals.  Their project has also included a piece of work to develop a data-logging module which TONIBUNG could use to track usage and performance; it could be used to justify investments, and improve the efficiency of system maintenance and future designs.

There are 17 Sustainable Development Goals which came into force in Jan 2016. They replace the Global Millennium Goals and are signed by all member states of the United Nations. Image taken from UN website here. 

We used breadboard for testing the
 ELC prototype and trying out ideas

To develop the design we are building prototypes which means make a few one-off models to test the idea and then making changes to the next prototype design. "ELC V2" was an early proof-of-concept prototype which has now been developed into "ELC V2+" - this is mainly the same design but with some modifications to the connections, and improvements to the software which make it closer to a design which is ready for production. A key change is that "ELC V2+" uses a printed circuit board (PCB) rather than the breadboard and stripboard which have been used in the development of the design.

Breadboard is normally used for initial prototyping because it is low cost, and easy to make changes to the design and test different parts of the circuit in isolation. Stripboard  is an insulating baseboard with a regular grid of holes and parallel copper strips running in one direction across one side of the board. It is more permanent that breadboard so that you don't accidentally move components or wires out of position! Printed Circuit Board (PCB) is used once the design is less likely to change significantly - it has the circuit ready-printed and holes drilled in the right places for the components to be soldered into.

Stripboard was used for the design which was tested in Sept 2016 (right). The underside of the board has copper strips which components are connected to with solder (an example is on the left).

The advantage of progressing the design to PCB is that it is easier to share and replicate the design relatively quickly and without making errors - it is much easier to see when mistakes have been made because there are limited ways that the components can fit into the allocated holes and it is easy to visually compare the board to a diagram. This means it is an easy way for the students in Scotland to share their design with us so that we can construct it on the other side of the world!

"ELC V2+" is constructed on PCB. These pictures show it half-way through manufacture

I have been assembling the PCB with the help of the Kinabalu Coders in their Smart Space in Kota Kinabalu (KK). Their Smart Space is full of cool projects based on Raspberry Pis, Arduinos and 3D printing and is a similar idea to Maker Spaces which have started up in many cities around the world - it's open to the public and free to use. I'll explain more about what they do there in another blog post because we'll be back there later in the week to do some more work on the PCB. In the meantime, here is the team and our friends at the Smart Space in KK with the progress we've made on the PCB so far:

More on the KK Smart Space next week!