Showing posts with label DIY. Show all posts
Showing posts with label DIY. Show all posts

2017-04-24

STM32 Nucleo HowTo

The Nucleo is not as popular as the Arduino, but here are some useful resources.

Excellent PDF to start with a STM Nucleo and a few components (Led, push button ...)  http://www.tamberg.org/fhnw/2015/LoRaWANIoTPrototyping.pdf Very basic, but very helpful.

The debug console

On Linux just use Minicom. You only have to specify 9600 baud. Other default values should be OK.

Type this in a terminal: 'minicom -b 9600 -D /dev/ttyACM0'.
And you should see the  'printf("Bonjour !\r\n");'  in your C program.

The pins, where to plug stuff

Of course it depends on your Nucleo board, but for the  L053R8, look at the Nucleo PinOut section. You have the Arduino and the Morpho headers, then focus on the PinNames.h file.
Also keep in mind the warning about D0 and D1 that are not usable, because shared for the USB communication.

Problem is that ST web site is a bit cluttered with tons of informations and it is not easy to find the relevant ones to start.

Next

I am still reading the ST various documentation, but I did not yet find anything as useful and simple as the slides (see above) 

2017-04-03

Midi keyboard AKAI LPK25 velocity problem

I have a cheap AKAI LPK25 MIDI keyboard. I it nice, but unusable due to unreliable sensibility. There is a utility: aseqdump that will dump MIDI messages. aseqdump -l will list the Midi client connected ; "-p client" will dump the specific client MIDI messages
  • ON PC, the plugin "MIDI velocity adjust" by Robin Gareus is excellent to compensate the poor physical MIDI keyboard.
  • Android does not seem to feature such filter. Neither does Caustic: http://singlecellsoftware.com/node/13935
To measure the problem:
$ aseqdump -p24 | tee lpk25.txt | sed --quiet -e 's/^.*Note on .*elocity //p'
 # Type some random string on the keyboard ...
$ cat lpk25.txt | sed --quiet -e 's/^.*Note on .*elocity //p' > lpk25.dat
$ cat lpk25.gp   
  n=127 #number of intervals  
  max=128. #max value  
  min=1. #min value  
  width=(max-min)/n #interval width  
  #function used to map a value to the intervals  
  hist(x,width)=width*floor(x/width)+width/2.0  set boxwidth width*0.9  
  #count and plot  
  plot "lpk25.dat" u (hist($1,width)):(1.0) smooth freq w boxes lc rgb"green" notitle

Finally plot the thing:
$ gnuplot -pc lpk25.gp
Velocity goes from 1 to 127. hitting the keys randomly for a while shows that it is not well balanced. There is a huge spike at 1. The aim is to set a minimum value somehow.

2017-04-01

Inspirational sites about IoT, DIY, makers ...

Continuing the quest for DIY components ...

Inspirational sites:



  • https://HackADay.io/
  • https://www.SparkFun.com/
  • https://www.itead.cc/
  • https://www.logre.eu/wiki/Commandes_groupées


  • Excellent PDF to start with a STM Nucleo and a few components (Led, push button ...)  http://www.tamberg.org/fhnw/2015/LoRaWANIoTPrototyping.pdf Very basic, but very helpful.

    Education about electrical motors

    I guess I should investigate the ST educational material. Looks like it is more in the spirit of what I want to do ...
    There are also tons of YouTube video to explains all kind of electrical motors. Not only brushed, brushless, AC, DC, universal ...

    2017-03-31

    Components for toy car hacking

    What to do with a Nucleo board STM32 L053R8 (Ultra-low-power ARM Cortex-M0+ MCU with 64 Kbytes Flash, 32 MHz CPU, USB) ... Some toy car robots ??

    Searching for components:

    Motor

    About 130 models at DigiKey.fr. 

    Lego

    Lego has a nice collection of motors:
    Well, might be easy ... too easy? Will it be adapted to the power control shield on the Nucleo??
    For the record Lego has also a pneumatic kit (80€).

    Starter kits

    Complete car or robots

    Kits look really nice, but you assemble and then what. Puzzles are not my kind of fun. A custom, original and risky robot will be better.

    Festival de la Cooperative OASIS - 2026

     https://Cooperative-OASIS.org/ Abonnement la revue Passerelle Eco    Papier . Mais les annonces sont dispo:  Revue trimestrielle de l’ Ecov...