Quoi de neuf 2017

From Eric

Experiments carried out in the past (from 2011) are described hereafter:

• 2016
• 2015
• 2014
• 2013
• 2012
• 2011

Contents 1 December 2017 2 November 2017 3 October 2017 4 September 2017 5 August 2017 6 July 2017 7 June 2017 8 May 2017 9 April 2017 10 March 2017 11 February 2017 12 January 2017

December 2017

• Played with the WT588D sound chip:
  

  
• Started to play with the XMOS startkit. Really worth having a close look at this multicore chip and its dedicated programming language (XC)!

November 2017

• Nothing

October 2017

• Nothing

September 2017

• Nothing (CAPHCA project @ IRT)

August 2017

• 15/08/2017
  • Painful investigations about RTOS on the Raspberry Pi. Tried Xenomai, FreeRTOS and RTEMS. Nothing runs really "out of the box". Some notes (in french) are available here.
  • I have received the PCB for the LT2944 breakout board from OSH Park:
    

    
  • I have managed to solder the tiny LTC2944 without a stencil: a magnifier, a pair of twizers with extremely thin ends and that's it. The games consists to push the soldering paste on the tracks "manually" and removing what is between adjacent tracks. (Things would be much easier with a stencil, but unfortunately, I don't have one.) Once the paste is at the appropriate place, I use a hot air soldering gun. The result is just fine. (By the way, don't clean a Osh park PCB with standard alcohol (not isopropyl) because it dissolve the nice purple vernish.
  • Here is the result:
    

    
    

    

July 2017

• 30/07/2017
  • Playing with the LTC2944 Coulomb counter from Linear Technology. This chip is used as a "fuel gauge" for battery-powered equipments. Here is a picture of the thing:
    

    
    

    
    Pretty small, isn't it?
    

    
  • I have "designed" a small PCB to make it easier to play with it (currently, I am using LT demonstration board connected to an Arduino). I should receive the actual PCB (from Osh Park) soon:
    

    
    

    
    

    
  • The Arduino code can be found here, and the Python script to display the sensors' values can be found here.
• 15/07/2017
  • I have built an ESR meter. The design comes from Jay_Diddy_B, see 5 transistor ESR meter design. Explanations are given in W2AEW blog (excellent video as usual, higly recommended blog)
    

    
• 14/07/2017
  • I have installed a bunch of NeoPixels (WS1812) in one of these old optic fiber lamps. To drive the pixels, I have simply used an Arduino pro mini with the AdaFruit NeoPixel library. The result is pretty nice.
    

    
  • I have built a Joule thief (a LED, a 2N2222 and a toroid self).
    

    
    

    
    

    
• 02/07/2017
  • I have bought a small 3D printer, the Trinus3D:
    

    
  • I have printed the small Bulbasaur that was pre-loaded on the SD card:
    

    
    

    
    

    

June 2017

• 25/06/2017
  • I have tried my little thermal printer :
    

    
  • I have used the library developed by Adafruit to print bar codes, and the library developed by grintor to print QR-Code. I read the QR codes with my mobile phone using Lightning scanning QR. Works pretty well. The printer user manual can be found here.
  • To generate and print QR-codes on my PC, I use QR Code studio.

• 24/06/2017
  • I have managed to use the fantastic DWM1000 chip:
    

    
  • [Edit 14/07] Did I write "fantastic?"? Well, it seems that I have destroyed one or two (or three?) of these tiny beasts. Curiously, only the DWM playing the role of TAGs seem to fail... Investigations are ongoing.]
  • This chip, manufactured by Decawave can be used for in-door localization. It is based on the measurement of the time of flight of radio waves.
  • I have used small Arduino pro mini at 3.3V to drive the chips. Hopefully, all the dirty work has been done by Thotro who provides a nice librabry, see here and there, on GitHub.
  • To solder the chip, I use a breakout board designed by Wayne and manufactured on demand by OSH park.
  • One VERY important thing to now: the power supply must be strong enough to support the peak current demands of the DWM1000. If the power supply is too weak, it will work very erratically. By the way, if you use one of those small breadboard power supply, do not forget to add a LARGE CAPACITOR (see the pictures).
  • Up to now, I only use the existing library which gives me 3 distances. Now, I have to implement some smart trilateration algorithm.
  • Here is a picture of the 3 "anchors" and the tag:

May 2017

Nada.

April 2017

Nothing.

March 2017

Void.

February 2017

Empty set.

January 2017

Null.