Friday, 5 August 2016

OLED - printing text to the screen

 OLEDs communicate with your Arduino via i2c.
Just 4 wires are needed.
 

Gnd
Vcc
Data connects to A4
Clock connects to A5 (Uno)
 
This is a basic start up splash screen.
There are 3 pages

Libraries Required :

  • Adafruit SSD1306
  • Adafruit GFX

The code:

// *****************

 // install these libraries
#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>

#define OLED_WIDTH 128
#define OLED_HEIGHT 64

#define OLED_ADDR   0x3C
// define the i2c address
// if you don't know the address, use a i2c scanner
// you can have over 100 devices connected

Adafruit_SSD1306 display(OLED_WIDTH, OLED_HEIGHT);

void setup() {
  display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR);
  // this begins the display
  display.clearDisplay();

  display.setTextSize(2); // range of 1 to 8
  display.setTextColor(WHITE);
  display.setCursor(0, 0); // first position on left
  display.println("Welcome");

  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(0, 17); // 17 positions dowm
  display.println("Page 1"); // just like a serial printer
  display.println("intro");
  display.println("display");

  display.display();
  //display function.
  // this is very impt .. it prints everything
  // from memory to the screen

  delay(5000);
}

void loop() {
  display.clearDisplay();

  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(0, 0);
  display.println("Jono");
 display.println("page 2");

  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 35);
  display.println("jondent");
  display.println("Synth Blog");
  display.println("jondent808@gmail.com");
 
 

  display.display();
  delay(5000);

  display.clearDisplay();

  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(0, 0); // 0 = collumn, 0 = row
  display.println("Jon's test");
  display.println("page 3");

  display.display();
  delay(5000);
}

// ****************** 

 Links
Thanks to Eli for the inspiration and great tutorials.
 

 ---------------------------------

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Wednesday, 3 August 2016

NLC Bong0 - Drum - Build notes

These are my build notes for the Bong0.
Its a Eurorack module from Non-Linear Circuits

"The bong0 is a twin-T based drum module with a LED acting as a nonlinear resistor to give it some interesting characteristics. 
 
Twin-T Oscillators
(sometimes known as parallel-T oscillators) are another type of RC (resistor-capacitor) oscillator which produces a sinewave output . They require an Op-Amp, some resistors & capacitors.
They are very similar to the Wein-bridge oscillator

The two "Tee" shaped RC networks are part of the OP-amp's feedback loop
between the output and input of the op-amps inverting amplifier.
Note that each of the the resistor & capacitor elements are in an opposing formation
but are connected in parallel.

Because the inverting input is used there is a phase shift of the oscillator by 180 degrees.
Note the "Ladder Network" of resistors & capacitors that form this feedback loop.
This is pretty common with RC Phase-shift Oscillators.

The trigger input acts as a normal input to get your drum sound. The input marked ‘in’ can also be used, or you can jam a CV in there, or a gate or audio. You can just use the ‘in’ input without anything into the trigger.


Bong0 can also be used for basslines, drones and as a crude but useful VCO. It has about 20 passive components which are 0805 smd and 1 thru-hole TL072, meaning it is a good circuit for learning to solder smd parts and delivers way more fun than such a simple module should." (Andrew F).


More Links:
1. Muffs
2. Build notes (NLC)
3. Panel art
4. NLC Blog

 
"Not a smoking implement" - NLC words of wisdom.






The pots are linear 100K






As you can see in these pics I used a green LED.
The LED acts as a nonlinear resistor so i think the type of LED you choose is important.
I couldnt remember the specific specifications of the green LED that I used , but I found that the volume was very low if used as a drum.

I decided to bump it up by swapping the 470K resistor with a 1M.
 If you check the schematics this is the second -ve feedback loop of the 072 op amp.
Andrew reckons it wont hurt anything....except my speakers if I crank it to self-oscillate.

I'll try building this with a blue LED next and see if there is any difference.
--------------
05/05/2018
Yes, the blue LED made a huge difference.
I kept the 470K resistor.


 


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You can find more NLC builds here.
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A side note regarding TT  or twin T oscillators.
Instead of using  a operational amplifier , someting like a logic gate could be substituted to provide the oscillations.
Ive seen a 4011 ic used as a tone generator.
 
The CD 4011 is cheap and includes 4 positive logic NAND gates on a single chip.
The NAND gate is a logic gate that gives a LOW output only when all inputs are HIGH
 

 
 See the RC network below.
The circuit is of a drum machine from the magazine "Practical Electronics", 1978.


NLC 1006 filter

This is based on the ARP 1006 filter.... from the ARP 2500.
The ARP1006 is called the Filtramp.... the NLC version doesn't have the Amp bit.
It's just a prototype - the panel is an extra Andrew had left over for the NLC Serious Filter.

The world doesn't have enough ladder filters. I really love this version and can't wait to compare it to a vintage 1006. The NLC 1006 contains a two input audio mixer & a voltage controlled 24db/oct low pass filter. The cutoff frequency may be varied with control voltages or by the front panel Fc control.

Guitar Fool have schematics and a BOM of the 1006.
http://www.guitarfool.com/ARP2500/1006.html


This is a scan of an old ARP-2500 manual of mine.

.



For more info:


More NLC words of wisdom

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You can find more NLC builds here.
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Sunday, 31 July 2016

Wiard - Malekko Envelator - quick start notes


The Envelator is a 10hp envelope generator (Function Generator).
This eurorack version was based around the Wiard 300 series of modules
developed by Grant Richter.

The version on the left is a vintage gargoyles. 
These date from around 2009/10.
I love these "Celtic" designs.
 
It offers simultaneous output of positive and negative envelopes as well as voltage control of attack and decay functions.
There are 3 types of envelopes: 
AR (attack release), AD (attack decay) &  CY (cycle).
AR mode, outputs an AR envelope, maintaining full level until GATE [in] goes “low”. 
AD mode, outputs an AD envelope, and begins decay immediately when
the attack stage is complete.  
Cycle mode, the end pulse is fed back to the envelope input, and will force the envelope to re-trigger.(triangle LFO). The SQR output functions as a square wave LFO

The GATE socket is where you plug your gate or trigger.
This input is a comparator 
The threshold is 2V so any waveform above this will work


The SQR socket is an output.
It puts out a square +10V pulse during the attack phase.
and 0V during the decay/release phase.

The END socket is an output.
It outputs a a pulse at the end of the decay phase.
 
 

This is the modern Malekko version. 
As with the vintage version, the attack & delay have two settings
They are operated with the push buttons on the modern version
and pull switches on the gargoyles version. 

Attack : has a normal & 10X setting.
Delay :When the switch is "in" the delay control does nothing.
It is only when in cycle mode that activating the delay control has an effect.
The effect is to introduce delay before the envelope re-triggers.

You have CV control of the delay time. "DEL CV" on the modern version.
"Ext" on the Gargoyles version.


Both modules have CV inputs for Attack Modulation (AMOD) & Decay Modulation (DMOD).

There are 3 envelope outputs:
-out : inverted copy of the envelope.
+out : two positive copies of the envelope.



------------------------------------------------------------------------------------------------------
Using the Envelator as a clock divider:

1. Clock signal into Gate socket
2. Use the SQR socket as the output of the divided clock.
    It puts out a square +10V pulse during the attack phase
    and 0V during the decay/release phase.
3. Use the Attack pot to set the clock division. 
4.  Works in AD and AR modes

--------------------------------------------------------------------------------
 Using the Envelator as a LFO:
 
You have both triangle & square waveform LFOs.
Put the module into Cycle mode.
Leave the decay control at max (fastest speed).
The end pulse is fed back to the envelope input, and will force the envelope to re-trigger. creating a triangle LFO.
The SQR output functions as a square wave LFO.
 
--------------------------------------
Using the Envelator to change gate length.
 
1. mode switch to AD.
2. end your gate to the Envelator's gate input. 
3. Leave the decay control at max (fastest speed).
4. The attack control determines the length of the gate.  
 
 -----------------------------
ADSR Patch
 
You will need two Envelators,  a mixer and a VCA.
1. Set 1st to AD mode, and 2nd to AR mode.
2. send the same gate to each envelator .
3. take outputs of each Envelator into the inputs of the mixer.
4. take the output of the mixer and input into a VCA 


The AD one acts as the attack and decay. The AR does the sustain and release.
The Wiard Xmix can be used as a mixer & as a VCA.
I find there is a little bit of audio bleed when I use the Xmix as a VCA.
I prefer to use a dedicated VCA for this task.
 
 --------------------
 

The -OUT is normalled to the AMOD input 
but you can  patch it to the DMOD.
 
This makes the DEcay curve bend up.
 

Friday, 29 July 2016

Foundation - Isaac Asimov's

Foundation is arguably the original sci fiction series.
The first stories were published in the 1940's during the height of WWII.
They take place over a 1000 year time period.
One of the main characters, Harry Seldon has invented / developed the concept of mathematical sociology
and psychohistory, where he predicts the demise of the human race and it's plunge into a 30,000 year dark age.

At this time, the Galactic empire sprawls. It covers the entire Milky Way.
Humans have even forgotten where Earth is.
To lessen it's suffering, he plans for the human race to create a foundation of scientists & engineers to preserve civilization and become the cornerstones of a new Galactic Empire.


Foundation is a cycle of five interrelated short stories, first published as a single book by Gnome Press in 1951, although the original trilogy of novels were published in "Astounding Magazine" between May 1942 & January 1950.

These stories were inspired by Edward Gibbon's " History of the Decline and Fall of the Roman Empire".


Foundation (1951) - first 4 short stories.
Foundation & Empire (1952)
Second Foundation (1953)

Isaac Asimov won the 1966 Hugo Award for "Best All-Time Series" for the "Foundation" Series.
This covered the original 3 books
This beat JRR Tolken for his "Lord of the Rings" and Robert A. Heinlein for "Future History" .


Asimov would write two further sequel novels and two prequels.
Asimov began adding new volumes in 1981.
The two sequels: Foundation's Edge (1982) and Foundation and Earth (1986)
The two prequels: Prelude to Foundation (1988) and Forward the Foundation (1993)

In chronological order, the books can be read like this


1. Prelude to Foundation


Publisher: Doubleday
Publication date: November 1988
Print (hardcover and paperback)
Pages    403
ISBN    0-385-23313-2












2. Forward the Foundation





Publisher : Doubleday
Publication date: April 1993
Print (hardback & paperback)
Pages    417
ISBN    0-385-24793-1
OCLC    29849055












3.  Foundation

Publisher: Gnome Press
Publication date 1951
Print (hardback & paperback)
Pages    255
ISBN    0-553-29335-4

It includes 5 parts:
1. The Psychohistorians was written for the 1951 book.
2. The Encyclopedists was originally published in the May, 1942 issue of Astounding Science-Fiction under the title of "Foundation". (This issue)
3. The Mayors" was originally published in the June 1942 issue of Astounding Science-Fiction as "Bridle and Saddle".
4. "The Traders" was originally published in the October 1944 issue of Astounding Science-Fiction as "The Wedge".
5. "The Merchant Princes" was first published in the August 1944 issue of Astounding Science-Fiction as "The Big and the Little"




4.  Foundation and Empire

 Publisher: Gnome Press
Publication date: 1952
Media type    Print (hardcover)
Pages    247











5. Second Foundation

 Publisher:Gnome Press
Publication date: 1953
Print (Hardcover)
Pages    210














6. Foundation's Edge

Published: 1982 (Doubleday)
Print (Hardcover, Paperback)
Pages    367
Awards    Locus Award for Best Science Fiction Novel (1983)
ISBN    0-385-17725-9
OCLC    8473906











7. Foundation and Earth
    Publisher: Doubleday
    Publication date: 1986
    Media type    Print (Hardcover, Paperback)
    Pages    356
    ISBN    0-385-23312-4
    OCLC    13123192









    --------------------------------

    As was mentioned earlier, though it was first published as a single book by Gnome Press in 1951,
    the original trilogy of novels were published in "Astounding Magazine" between May 1942 & January 1950.

    The Foundation Magazine issues.
    You can download them from the Internet Archive.

    Foundation - first 4 short stories.

    Foundation Part II: The Encyclopedists
    May 1942, pages 38-53 (Foundation)

    Foundation Part III: The Mayors
    June 1942, pages 9-30 (Bridle and Saddle)

    Foundation Part V: The Merchant Princes
    August 1944, pages 7-54 (The Big and the Little)

    Foundation Part IV: The Traders
    October 1944, pages 64-79 (The Wedge)


    ** Note, Part I didn't appear in the magazine. It's first appearance was in the 1951 book. The opening section of Part II was not included in the book publication ***



    Foundation & Empire (3 magazine issues)

    Foundation and Empire Part I: The General
    April 1945, pages 6-61 (Dead Hand)










    Second Foundation (4 magazine issues)

    Second Foundation Part I: Search By the Mule
    January 1948, pages 7-61 (Now You See It...)








     Links
    + Wiki pedia
    + Hugo Awards Best sci fi novels of the 1960's

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    sci Fi Index

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    Sunday, 24 July 2016

    Segue - NLC - VC panner/crossfader

    These are my build notes for the Nonlinearcircuits Segue.

    Its a very versatile unit. a VC panner, VC cross-fader, VCA and VC attenuator, process CV and audio.
    Plus should be a easy build.  Though there are plenty of SMDs, they are all passive.

    Andrew describes this as a "kind of hybrid between a Buchla 207 panner and a Korg PS3200 VCA".

    There are just two through hole 10R resistors to instal.
    Then, caps, trannies, headers.
    The trim pots are all 100k.They set the gain for each channel.

    I'm using Silonex NSL 32 vactrols. The white dot marks the cathode. (K on the PCB).

    NLC words of wisdom: (He'll never be) an old man river.
    Mmmmmmmm ????

    The reference to "Ol' Man River" isn't the song from the 1927 musical of showboat.
    Rather it's refering to TISM ... the Australia band.


     
     OK, its time for the pots & jacks.

     The LED works.... so does the VC fader. Very cool.

    "The LED provides offset to one side of the current mirror so they turn on/off at different voltages." Andrew F advised me to "drill the panel, or just drill/scrape off the soldermask on the back and the LED will make the panel glow".





    Useful links:
    1. Andrew's Blog
    2. Youtube 1 - Wear Headphones
    3. NLC build notes

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