£55.71 import duty* later…

and this is what UPS handed over to me in return.

Scanse Sweep 2D LiDAR tracker

Scanse Sweep 2D LiDAR tracker

First impressions are extremely good which bodes well for meeting my high requirements and expectations.  The box is sturdy, and the contents are not going to get damaged in transit; in addition to the Sweep itself, there’s

  • a custom UART / USB adaptor that’s small and slick
  • one USB A to micro-B for a PC connection – as cables like this go, this is probably the slickest looking I’ve seen – flat cable with very tidy connectors
  • one JST to bare wires to add your own connection – this is probably what I’ll be using to attach to the RPi UART ttyAMA0 as its the same wires that my Garmin LiDAR-Lite uses so I have spares
  • one cable I have no idea what it’s for – JST at one end clearly for the Sweep, but no idea what the other end’s for
  • a sticker, oddly requiring microwaving to make it sticky – I’ll be keeping this boxed!
  • a quick start guide.

I’m not in a rush to install it on Hermione; it’s too expensive to risk while I’m busy testing out the GPS, compass and yaw code – but I will put together a basic system, probably on my piPad.  That’ll let me check whether my double 2.4A battery bank is sufficient for both a B3 and the 0.5A the Sweep needs – I suspect this will be the first problem I’ll be having to fix; certainly, the raw Garmin LiDAR already runs off it only 2.4A feed due to power problems.

*I’m glad we are part of the EU and the free trade agreement means there is no import duty – oh no, wait, feck, argh – BREXIT! }:-{(>


At some point in the not too distant future, I’m going to need a much longer range WiFi connectivity between my piPAD and piDrones so that I can test the GPS tracking in the local field where the piDrone and piPad may be separated beyond the range of the current direct WiFi signal.  This is a problem because I need connectivity even though the piDrones are autonomous as I always need to be able to press the remote kill switch.

I considered for a second or two hunting down a longer range radio system, but then wondered whether this is doable by using multiple Zero-W’s instead: the concept of piNet was born.

The idea is that these Zero-W’s are all in their own private network (piNet) using their inbuilt WiFi.  The Zero-Ws are phone charger battery-bank powered, and are scattered  around the test field.  Each Zero-W also has a USB WiFi dongle configured to connect to the piDrone WAP network.  The piNet and iDrone networks are bridged together.  My piPad is also in the piDrone and piNet networks.  That means I should be able to access the piDrone network via piNet even if the piDrone is outside of the range of the piPad WiFi: I should be able to remote login to the iDrone from my piPad via piNet.

This feels like it could work with the piDrone clients bridged to the piNet, but there’s lots of details I have no idea about.  More thinking to do.

B3 bluetooth keyboard

I bought an Anker bluetooth keyboard for my B3 piPad, and have spent 10 days periodically swearing at it trying both the CLI or GUI app.  Finally, I found a complete set of instructions on the RPi forum that worked.  Type following commands from a console:

  1. bluetoothctl
  2. pairable on
  3. scan on
    Now you have to wait, until your BT device (keyboard) is shown (don’t forget to activate your keyboard now! Press the so called “pairing button” of your BT keyboard, may be a combination of two keys, see the users manual!). Don’t forget to wait!!! You should see it’s address as “xx:xx:xx:xx:xx:xx”
  4. scan off
  5. agent on
  6. pair xx:xx:xx:xx:xx:xx
    Now you are requested to input a number (6 digits) using your BT keyboard, and then you have to quit it by pressing the “return” button of your BT keyboard! “pairing successful” should be displayed!
  7. trust xx:xx:xx:xx:xx:xx
  8. connect xx:xx:xx:xx:xx:xx
    “connection successful” should be displayed!
  9. info xx:xx:xx:xx:xx:xx
    … will show the success again (some Information are displayed).
  10. exit

Reboot your RPi now.

Fixing Florence

I mentioned the other day I had a couple of problems with Florence, the touch screen keyboard I use with the RPF official 7″ touch display.  One was a whopper – touching any of her keys caused her to vanish permanently.  That’s now fixed by this installation:

sudo apt-get install at-spi2-core

The other problem was getting Florence onto the Application Launch Bar. In the main menu she appears under “Universal Access” but this isn’t in the “Application Launch Bar Settings”.  I found the solution on StackExchange, with one minor tweak.  Where it mentions changes in


you need to make those changes here:


Finally, if you want to adopt the same Raspberry coloured keys as I have, add a custom colour of #D62B4F.  This is the colour of the official Raspberry Pi logo.


I saw this stand in the Raspberry Pi forum and ordered one from Amazon.  It arrived yesterday.  It doesn’t protect the back, but the 7″ screen fits beautifully.  The stand is collapsible and the display stands on soft rubber.  Best yet, it’s non-slip so the touch screen works well: no slipping when you use the touch screen.  I also upgraded the OS to jessie and installed the jessie version of Florence, the virtual keyboard.  Florence is much better: all the keys have letters / icons and the opacity of the background works (you can see the apps behind the screen.  I still have a couple of problems to resolve, but even like this, Florence is much better.



Living in a cardboard box

I’m now on my third case for my piPad, and it’s the best yet.

piPad cardboard case

piPad cardboard case

Inside the cardboard box

Inside the cardboard box

My first was from Pimoroni, which was lovely, but offered no protection for the electronic behind.  The support legs are rigidly fixed.  Together this meant my piPad was not protected for carrying to the Cotswold Jam (tickets selling fast, buy them while you can).

Pimorino Touchscreen cover

Pimorino Touchscreen cover

The second was this one from Farnell.

Do not buy this case

Do not buy this case

Frankly I’m now embarrassed to say I bought it.  Although it offered complete protection of the electronic, it is critically flawed in several ways:

  • the only place to power it was via the Raspberry Pi micro USB socket; that’s not one of the three recommended ways i.e. power the display and RPi boards seperately (as per my cardboard box) or power the Raspberry Pi from the display board either via GPIO leads or a USB A to micro USB cable.  I ended up doing much dremelling to open up the case to be able to access the display board micro USB socket  and power both boards separately
  • that done, I installed everything, but then I found that it was unstable – using the touch screen pushed the display over!
  • finally, I _think_ the case puts too much pressure on the cables to the display and touch screen and may have damage my touch screen cable.

It’s now ‘out of stock’, perhaps due to the several support issues I raised with Farnell about this case’ completely inept design.  I wouldn’t normally post about faulty designs on-line, but since I’ve had no response from them, I feel I must.

My advice, avoid like the plague!


My piPad is finished and WAPping nicely with Phoebe.

piPad and Phoebe WAPping

piPad and Phoebe WAPping

piPad and Florence

piPad and Florence

Loving the raspberry coloured keys.  One last problem: I can’t find Florence’ colon* 😉  It does make editing in vim quite hard.

A few notes:

  • powered by a 5V 2.1 LiPo battery bank
  • video cards and RPi independently powered by the bank via a USB cable splitter – powering the Pi via the video cards GPIO’s or Vout USB A socket leads to reduced voltage for the Pi (rainbow square in top right of the screen is the ‘underpowered’ warning
  • florence is a good as she can be but she lacks the finer touches shown on other linux implementations – I presume due to GPU capability for rendering opaqueness / transparency – the default Raspiand distribution upgrade from Wheezy (version 0.5.1-1) to Jessie (version 0.6.2-2) will hopefully help when that happens.
  • florence also doesn’t not have access to a font with the right symbolic characters so her special keys are blank – not the end of the world, just less pretty
  • Once she’s scaled to a size suitable for the 7″ DSI Raspberry Pi screen, I needed to use a stylus even though I have tiny fingers.

She’s met her requirement to control Phoebe in flights so I can follow my purity desire and use the piPad instead of my iPad to control Phoebe’s flights.  That’s how I’ll be doing it at the next Cotswold Jam.

*No seriously, can you see a colon on the keyboard? It sometimes appears with a set of keystokes I’ve not yet tracked down, but mostly it just vanishes down a black hole.

P.S. Found it – right-shift + ‘;’ what made it hard for me was that neither left-shift nor caps-lock revealed the colon, only right-shift does it.

No more need to take my tablets

to the Cotswold Jam to control Phoebe.

Raspberry Pi 7" touch screen

Raspberry Pi 7″ touch screen

Powered by a Vinsic 5V 2.1A battery bank, and right angle USB cables from StarTech, and framed by Pimoroni in Flotilla blue.

With “florence” installed as an on-screen keyboard which works well with the 7″ touch screen DSI. The software is part of the standard Raspian distribution.

sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install florence