Archive for December, 2017

Stuck again

Posted in The downside of Opensource, The Downside of software development on December 18, 2017 by asteriondaedalus

So, I have my iPEGA bluetooth gamepad and I am wanting it to run from my dopey Android phone that I am using as the mediator for the rover.

Nothing useful for using these gamepads in Processing for Android so that appears to be out.

No heart or interest to write something in Java.

Python?  Well pygame for Android seems a dud, a lot of old blog entries but nothing obviously working anymore.

I noted that they sorted some of the flakiness of Kivy and so I re-installed Kivy on my PC with the view of prototyping on Windoze then bombing on Android.

Go figure I can get the pyGame gamepad exerciser working on PC.  I tried the same for the raw Kivy version.   I works!  Well as long as you don’t allow your gamepad to go to sleep.  If you do, Kivy drops it.  And, if you leave it disconnected long enough, the Kivy application closes down quietly.

Posted a question on Kivy.org and an issue on github but no responses at all from anyone.

It is not obvious from the Kivy code why it drops the gamepad.  There is otherwise no hints in any of the examples or any of the documentation.

In the pygame version, the gamepad can go to sleep and when it wakes it is auto-connected again.

So, stuck as I still have to see if I can get the old pygame for android to work with the gamepad.  I would have used Kivy but help is a dead end.

 

Advertisements

Cheap lidar

Posted in Home Made Lidar, Sensing on December 9, 2017 by asteriondaedalus

So my Benewake TF Mini LiDAR turned up.

TFmini

Now for the fun.

It has to rotate in a circle to create a scan.

I had an idea to mount either of a Seeeduino Film or an ESP8266, with battery, on a spindle to wirelessly send readings – all while it is spinning.

Then BOOM!

You can get “hollow” spindle gimbal motors with slip rings!  So, again a

So, you can attach the TF Mini to the spinning part of the gimbal motor and drive the motor and take readings.

All good but for one thing.  Currently the idea is a open-loop solution.  It will need to be keyed to at least one position (at least) so that the “beams” are relative to a direction.

Hmmm!

So, being lazy I found a really cheap MEGA328P driven gimbal board, but I only want it for the gimbal driver and the ease of software hacking.

HMBGC

The beauty is is a clone of the Martinez toy, so it has code to manage the phases of the motor inputs.   Should be interesting as it looks like you only need a few functions to set it up to run a motor continuously, but who knows – I still have to read into the theory.

So much help, so little help

Posted in The Downside of software development on December 8, 2017 by asteriondaedalus

So, I stupidly thought I would upgrade my elixir and crack open my book on Phoenix and plod through the examples while home sick with the flu.

Book is Programming Phoenix (eBook) P1.0 from PragProg

Broke the build so I had to strip out the hex and mix folders, re-installed hex, elixir and phoenix.

And then all I got was the broken connectic with postgres!  Why?  I was going to up from 9odd to 10 but backed out after I saw how long the 10 would take to download (and it wasn’t needed).  I had already uninstalled 9 and just re-installed.  BUT the build would fail as the username/password failed on authentication.

Hmm.

When you delete postgres on windows it doesn’t, of course, remove the data directory (where usernames and passwords are encrypted).   If you reinstall overtop a bug or quirk of the install is that it not longer prompts for super-user password or port etc.  (obviously buried in the data directory).

All fixed by manually deleting the data directory and re-re-installing postgres.

POSTSCRIPT

GAG!  My book appears to be out of date now!

At least, they have moved all the app directory structures around.

Pragmatic Programmers KEEP UP!

Although, it looks to be the difference between Phoenix versions 1.2 and 1.3 which is fine (just have to remember to use the phoenix.x rather than phx.x idiom for building apps).

POSTPOSTSCRIPT

There are problems with the errata page, as rather than the author drafting errata, as people report the problems, the errata is like a user group and so you get the same drifting away from facts.

Although, problems include movement in version of ecto as well.

If there is an error, go figure there will be at least two solutions offered by readers BUT as they don’t state the elixir, phoenix and ecto versions that they are using (while working through the book) you need likely try each of the different solutions until one works for you.

Looks like best option is to install the elixir, ecto and phoenix versions from the book.

Still, I have had to work things out that don’t appear to have been reported in the errata so I guess I am learning little tit bits along the way.