Amazonians fly!

Only just stumbled upon this:

Cool, but safe and financial viable?  It can only work in low density population areas outside of CAA restrictions (that counts me out); each base station covers only a 10 mile radius; the luggage is limited in size and can weigh up to 2.3kg (5lb).

DJI Mavic shopping list

First, just pay the extra £350 and buy all the extras with your Mavic:  two spare batteries, multiple battery charger, car charger, phone charger, spare props.  No point going to an amazing location and taking only one battery and no chargers.  There’s also a bag, but it’s useless once you have the essential travel necessities too.

Instead I got a Peli iM2100 storm case.  There’s a B&W equivalent with laser cut-outs, but I prefer to do my own hole making for exactly the pieces I need. And the peli case was available unlike the B&W equivalent.



Joystick clamp: with a custom cutout peli case (and actually even with a laser cut B&W), it’s worth keeping the joysticks on the RC aligned in storage as the instructions say.

Launch pad: not a necessity but there is good reason – on take-off there’s a pause while the Mavic photographs the takeoff point; on return to home, GPS gets the Mavic most of the way home but the launch pad recognition gets it to within a few centimetres.

Landing Legs: unless you’re on a hard, dry surface you’ll need these little legs to keep the camera and gimble off the ground and away from the damp grass.

Cheap mobile: No point risking your iPhone or Samsung when a £60 Android will fit perfectly and provide a fantastic 5.5″ screen; no SIM required though if desired, this one supports 3G, and it’s £69 sibling adds 4G and LTE.

P.S. I’ve found a couple of other options worth mentioning:

For the joystick clamp, I’ve swapped to this one, which is injection molded rather than 3D printed. It’s a better design, a better finish, and cheaper.

For connecting the cheap mobiles to the RC, none of the standard adaptors supplied by DJI work. There are two choices:

Neither option is perfect, just make your own choice.

Pure, unbridled fun!

While building Phoebe, Chloe, Zoe and Hermione over the last 4 years has been fascinating, frustrating, intellectually challenging, educational, satisfying, and critically, a brilliant-boredom-blocker, it’s never once been fun.

When I first started this project, there were many DIY quadcopter projects and very few commercial ones, and the commercial ones absolutely needed a skilled human with good hand-eye coordination in the feedback loop.  4 years later, the DIY market is shrinking because the commercial market has caught up and overtaken them; they now support vast amounts of autonomy to protect themselves from less-competent humans like me.

The best ‘affordable’ one currently is the DJI Mavic Pro.  It has 24-core, GPS, several URF  and video sensors for object avoidance and vertical / horizontal tracking, return to home, tracking a target and a stable gimbal for great photos and videos.  It folds up tiny and so portable.  And it costs £1k; I’ve spent many multiples of this on the development of Phoebe, Chloe, Zoe and Hermione.  So I’ve bought one and it arrived today.  After two hours charging, setting up etc, it was dusk, so I only took it out for 5 minutes.  And came back in beaming from ear to ear!

DJI Mavic Pro

DJI Mavic Pro

P.S. Development of Hermione with compass and GPS, and ultimately Scanse Sweep, will continue in the background, but currently, that’s blocked by the fact the I2C errors came back last week, despite there being no code nor hardware changes between the day she worked and the day she didn’t. Blind paralysed sterile stag (still no-fecking eye deer) why 🙁


I don’t do free advertising but…*

sometimes, someone gets in touch and because I think it’s a great concept, I will give it a mention.

Previously, this happened with Kano, a fantastic starter kit for the Raspberry Pi.  They sent me a Pi 3 kit to try, even though I warned them I probably wouldn’t have the time to do anything with it.  True to form, it gathered dust on my desk for 6 months, at which point (with Kano’s permission) I gave it away as a prize for the Cotswold Raspberry Jam.

Today, something very different got in touch: Omega 2 – a tiny Linux computer, even compared with the Pi Zero, designed specifically for IoT stuff.  It’s outside my area of interest, but as it seems like such a well thought through device, and isn’t in conflict with the Raspberry Pi Foundation aims, I thought I’d share.  I’ll leave it to you to make your own o(pi)nion!

*To be absolutely clear, I don’t do paid advertising either. I only mention stuff I’ve used that I’ve needed, stuff that I’ve stumbled across that looks cool, and vendors who have provided exceptional service.

Dear Royal Mail,


Why has it taken 3 months to fail to deliver 3 packages to me from Ragworm?  They’ve jumped through flaming hoops resending my PCBs when they don’t arrive within a week of dispatch, and yet none have arrived yet.  They were ordered on 1st August, and are still not in my hands despite Ragworm despatching each set pronto.

And while we’re on this subject, why is the SparkFun Garmin LiDAR-Lite V3 still stuck in Heathrow airport a week after it arrived, despite all duties / taxes being prepaid?  It’s taking longer for it to travel the 75 miles from Heathrow to here than it took to travel the 4657 miles from Colorado to London.  USPS, there must be a market here for you to take over.

It’d be quicker and more guaranteed service to stick these on my Santa list.

Patiently waiting,



The Last Post…

…on the EU referendum results.  I simply feel the need to inform Brexiters that they were conned and lied to.  It emerged almost immediately on Friday morning that Nigel Farage, Boris Johnson and Michael Gove had lied that they would fix  immigration and fund the NHS.  Don’t believe me, I’m obviously biassed.  But do google for yourself, and form your own opinions about these three fraudsters.

And then, Brexiters, if you do feel conned, write to your MP, and sign the petition to make your opinion clear.

OK, that’s it on politics from me, back to quadcopters.

Dear Remainers and Brexiters alike,

The referendum still needs to be approved in Parliament. We can still stop the process.

Please put aside your personal concerns and consider the impact this will have on today’s youth and generations to come.  The youth voted to remain in the EU – it’s they that we, their parents, guardians, grandparents and family, have failed if we leave the EU.

The majority of MPs are Remainers. Please write to your MPs to ask them put the future of our kids and the youth of today ahead of their personal wishes.  Ask them to vote against leaving the EU. This is the last chance we have to come together and stop the damage to our childrens’ lives for generations to come.

Click to find out your MP’s contact details based on your postcode.

Please, everyone, Remainers and enlightened Brexiters alike, write to your MP – this is our last chance; seize it.


Nope – I’ve not been scything the garden with Chloe or Zoe, it’s off-topic about an eco-weedkiller I found out about from the neighbours that I thought worth sharing.


  • 5 litres vinegar (£12 for 20 litres from Amazon)
  • 2 tbps salt (free from the kitchen)
  • a dash of fairy liquid (or other brand) to break the surface tension (ditto)
  • a 5 litre pressurized garden spray (£8 from Amazon)

Spray it on the nasties – we have wild rhubarb, nettles, ground elder and giant hogweed (a more virulent, smelly and ugly version of cow parley).  All of these have large root systems – kill one batch, and another batch springs up feet away.  After spraying ours yesterday, today they are all looking decidedly dying today and I strongly suspect the root system is suffering too.

Why not use shop based weed-killers?  This stuff is better, cheaper, ecologically sound, and therefore safe for our chickens and kids to play at the same time.

The only downside seems to be the “Chip Shop” smell for a day or two.  Like Marmite, it’s a love it or hate it – I love it!