• Weeks 144-145

    3 August 2015

    A busy couple of weeks, both on Selworthy and Twinklr.

    This fortnight saw the last few features added to Selworthy before it goes into a period of deployment and re-architecting. Some were minor patches, but one overhauled the shape of the permissions system somewhat. A combination of diligent QA and automated testing helped there. It’s in a pretty good place to be taken forward into its production environment now – which is going to be my main focus in August.

    I also spent a while building up the user-facing documentation for it in Zendesk. Selworthy is a complex tool; whilst we’ve tried to make it as intuitive as we can, clear documentation (especially around the various user roles) is also an important deliverable: once that reference is available, we can help users on the path to mastery more easily. Rather than writing it as a long swathe, we’ve been building it inside a “knowledge base” tool. That’s been really useful: it makes it easier just to hyperlink between articles, rather than duplicating information, and the shorter chunks make it much easier to rewrite over time.

    Twinklr’s going well too. I went along to the Hardware Coffee Morning to have a chat with peers and show it a little; ironically, I mainly showed the software component of it. That’s pretty much where I’d like it to be for the time being, so the next thing is getting the hardware to 1.0 too.

    That was the focus of week 145: I finally began the process of manufacturing self-etched single-sided PCBs. Whilst these are still relatively simple, they’re a step away from stripboard and jumper leads, and it’s been a useful thing to learn. By the end of the week, the layouts for the very simple Teensy breakout and less-simple amplifier were complete in Fritzing, and I’d managed – after a day of varying all the variables – to etch a single-sided PCB to my satisfaction.

    I’m using toner transfer to make the etch mask: print an inverse of the mask on glossy paper with a laser printer, line it up with the PCB, and then iron it for about six minutes; the toner comes off the paper and ends up on the PCB. Then, fifteen minutes in a ferric chloride bath, and the copper all etches away – apart from where the toner covered it. Frustrating the first few times, but I found the knack in the end. I think the next project after this might involve getting double-sided boards manufactured – but a combination of time and availability has meant that DIY has been the way ahead. Very satisfying to spend some mornings in the workshop, too, rather than at a desk.

    Next week, I’m going to drill it, solder it up, and do the same for an amplifier board. That should take very little time – leaving the rest of my capacity to go on to pushing Selworthy through to launch.