Training, Notting Hill Gate, day 4

Big fish!

…on my walk in each morning, I’d been by this shop, each and every day I wanted to steal the big fish just a little bit more. Thankfully I didn’t, it would have been somewhat impractical on the train journey home.

Fish aside, it was the last day of the training for me and Ash, we should all have been there the whole week, but Hannah had other commitments and had finished on the Wednesday, I had to travel back Thursday (the day of this post) due to train strikes on the Friday (the day I actually upload this post), and Ash was desperately needed back at his base in Cardiff, as the site has only just opened and he had a mountain of setup still to do, and hordes of visitors wanting to go and look at the place… So with this in mind, myself, Ash, Charlie and Paul, all readied ourselves to make the air quality monitor system work as advertised…

Group Project – Air Quality Monitor


Initial tests of the system showed a number of bugs, while we had successfully tested subparts of the overall system, combining them all together to produce the full system introduced a number of timing and delay errors that needed to be tracked down and eliminated. Today we need to make the system work in its entirety.


The system was fully assembled and a number of runs of code from the previous day were used to test the input and output systems, while code from the main controller was revised and edited a number of times to eliminate timing issues, and introduce an element of debugging capability so we could watch each stage of the protocol at work.

A number of small bugs were located in one of the output modules, where it was sending on an incorrect radio channel (A change made late in the previous day), and another where it didn’t mirror its output status onto the LED screen, so it was hard to keep track of why the output kept going high, yet the display showed everything was still off, this was debugged by Charlie on closer inspection of my original code, which he had duplicated and adjusted to control a Neopixel output, rather than a servo.


Changes from the previous day included isolation of the input signals from the control modules to the main, into their own radio channel (moved from channel 1, to channel 2), leaving channel 1 purely for the output signals alone, as early on we had suspicions that due to buffering with the microbit radio receive, that we could be causing a huge delay by the application being so radio heavy, by forcing each Microbit to look through a mountain of messages that may not be relevant.

Sensor module code was cleaned and made more efficient, as a deeply nested logic loop in  the sensor module code appeared to have issues during compilation causing significant slow down and delay in reporting and response of its signal data.

Personal Contribution

Once again I took the lead on making the test code and prompting hardware that can be used to trigger both input events, and test control outputs.

Final results

On the test bench the system eventually worked exactly as planned, with risk events (simulated using handwash, as it has a high alcohol content!) triggering appropriate alerting or corrective action as defined by the main controller. It worked!

Further development

Designing cases and making the system viable for use in the Lab network, further clean up of the code needed (may personally re-write in MicroPy just to neaten it up) and refinement of UX to give more useful display feedback on the system status. Perhaps using button A to toggle the display between some kind of status page.

We did it! We made it work, despite the battles with Microbit radio (need to play around with that more outside of Block Editor, I am suspicious of the compiler used), we made a functional air monitor and management system. It was a good week too, nice to have the engineers together working on a joint project and working to a common aim… Long may that continue in to 2018.

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