Zoe did her stuff at the Cotswold Jam reasonably well, but she consistently drifted to starboard (right), even when I was safety testing her outside before hand at a much lower temperature.
The previous day, I’d also safety tested her indoors and she drift consistently backwards are about the same speed.
The setup and software for the two days was the same, except I’d removed the props for transit to the jam.
Could the difference in drift direction simply be the props? Had I rebuilt her at the jam with one diagonal pair of the props swapped compared to previously? That could account for the 90° change of drift. Certainly the change in drift does point heavily at the props. The props are plastic and they bend easily and permanently. So I now have some sturdy CF props on the way which I hope will limit the drift in time for my work engineering conference at the end of the week.
Zoe at 1kHz sampling, 8s flight from Andy Baker on Vimeo.
If you are interested in what triggered the transformation, have a look at these comments.
The net results are I’m getting perfect data reads at 1kHz sampling and alpf set to 2. And that’s as good as the sensor can possibly provide.
So Zoe is good enough for the Cotswold Jam on Saturday (sold out, sorry), and my employer’s Engineering Conference the following week, and hopefully the Raspberry Pi Birthday Party in early March.
There’s probably some PID tuning to be done that might stop the low-frequency wobbles due to the gyro PID I gain being a bit too enthusiastic. That would then curtail the drift too.
I’ll post more videos if that turns out to be true.
So the spoiler in yesterday’s photo was another quadcopter flight controller to the left of the keyboards, pending the release of a fantastic new range of quadcopter frames which is being launched next month. More on that once I’ve got my grubby mitts on one.
But that A+ controller has now been flushed down the pan with the launch of the Raspberry Pi Zero, smaller than an A+, double the memory and just as powerful in every other way. I really have know idea how they halved the size of the PCB and yet kept all of the function. And it’s £4 (yes, that’s not a typo, four quid for a computer that runs Linux happily!), and free if you buy this month’s copy of the MagPi magazine.
So I now need to redo the design for the beret board, to shrink it down to the Pi Zero size!
If you’re in the neighbourhood, pop down to the Cotswold Raspberry Jam in Cheltenham on Saturday and see the Pi Zero for yourself!
The next Cotswold Jam is now confirmed – more details here
Cotswold Raspberry Jam
There are still some tickets left for the yummy event! Drop by and see the fruit and nuts!
Yet another confidence building test flight from Andy Baker on Vimeo.
I’ve flying Phoebe virtually every day the weather allows in preparation for the indoor demo flight for the CotswoldJam on 26th September 1pm – 4pm at the University of Gloucestershire in Cheltenham. I can confidently say she’s safe.
P.S. Sorry about the video quality, the camera really didn’t the shoot in the shade with sunshine back light.
Phoebe’s “Prior Preparation and Planning Prevents P1$$ Poor Performance” as my german teacher used to say 30 years ago. So I’ve been doing periodic testing in preparation for safety approval on Wednesday to fly at the Cotswold Jam on the 29th.
This morning, I realised there was once further micro tweak I could do which might have a significant effect. What do you think?
PPPPPPPP from Andy Baker on Vimeo.
This is a 12s flights (3, 6 and 3s at ascent @ 30cm/s, hover and descent @ 30cm/s). To put this in context, previous good flights I videoed have lasted for less than half this. The tweak was simply to change the initialisation code measuring the angle of takeoff. The drift is more than it would be indoors as there was a breeze.
The code ‘s up on GitHub.
Tickets for the next Cotswold Raspberry Jam on Saturday 26th September from 1pm to 4pm are now available via the Cotswold Jam website.
Cotswold Jam and Cambridge Robot Wars
Unless I manage to break Phoebe before December, I intend to take her to the Cotswold Jam in September (where I’m one of the founders / organisers) and the Cambridge PiWars in December.
The code I’ll be running there will most like what I uploaded to GitHub yesterday.
Over the next couple of months, I’ll probably just enjoy flying Phoebe and Chloe, and perhaps treat them to some new batteries – primarily so the colours match the rest of their frames!
I might add an angular (rather than motion) control version so I can show the difference in behaviours at the Jams.
Otherwise I’ll try to keep my tinkering to PID tuning unless the A2 appears leaving me enough spare CPU’s to play more with threading (QCISRFIFO.py), Kitty and Kitty++.
What I won’t be doing
I won’t be adding a human into the feedback loop – no remote control – sorry to those of you who have nagged me to do this.
I also won’t be blogging as much as I’ll have less to blog about, other than flight videos. Also it’s clear from the blog stats people are starting to get bored…
Blog bandwidth usage
The underlying decline actually started in February but hidden behind the Build Your Own Automomous Quadcopter – Bill of Materials, Assembly and Testing (BYOAQ-BAT) articles in February, and the fact PC World included me in their 10 insanely innovative, incredibly cool Raspberry Pi projects article in March.
So I think for a while it’s TTFN but no doubt I’ll be back.
After a couple of months searching for a new location, we’ve found the perfect new home – the new Computing Sciences department at the University of Gloucestershire in Cheltenham.
The next Jam is likely to be on the 26th September, assuming the builders have finished their work – yes, the location is absolution brand spanking new. Updates on what’ll be in the next Jam will be on facebook, Twitter, and on the website.
Very, very excited!