Building Your Own Wave Analyser/Oscilliscope, Use LabVIEW or Any Sound analyser for Output

Yes, you read it right, you can make your own Wave Analyser or in simple terms, an Oscilloscope, that too costing less than 1$ (1 Dollar). An oscilloscope, if you are looking for it in the market, you will obviously get it, but you have to spend a heavy amount from your pocket on it.

The secret behind our oscilloscope costing much less than a regular one, is using many readily available things that are available with every electronics hobbyist.

Things you’ll need to start with this oscilloscope are
      # Your Computer's Sound Card (connection through Line-In Port)
# Wires (prefer metal shielded cables)
# Some Resistors
# A 3.5 audio jack ( which can be taken form a dead earphone )
# A Zener diode
Yes that's all you are going to need for it!

Before you go further, we suggest you to have a glance on how 3.5mm Jack or TRS Connector works. Just follow this link for that, http://www.divilabs.com/2013/03/how-do-35mm-jacks-trs-connectors-works.html.

Now we hope that you have got some idea (conceptually), how your oscilloscope gonna work! Its all about measuring voltage across the Tip, Ring & Sleeve of your 3.5 mm jack or TRS connector.
NOTE: A stereo extension cable for earphones can be taken if one does not have a cable available. The stereo cable plugs  into the "line in" jack on the sound card of your computer system.
So lets proceed with how you are going to make the connection of this oscilliscope....
3.5 mm Jack or TRS Connector as Wave Analyser or Oscilliscope
3.5 mm Jack or TRS Connector as Wave Analyser or Oscilloscope


Important Design Considerations:
Sound cards are designed only to accept in a range of one volt or two so we used a voltage divider mechanism, rather than connecting wires directly to it, to limit voltage going towards the sound card, two pairs of resistor of ¼ watts which acting as a voltage divider. The voltage across each channen can be just calculated by the simple formula V2= (R1/(R1+R2))V1,  as illustrated in the figure...
Voltage Divider considerations for our oscilloscope
Voltage Divider considerations for our oscilloscope
In our oscilloscope, the 10k resistor will be R1 & the 91k will be acting as R2 of the voltage divider circuit above mentioned. Here the Channel 1 & 2 have a common ground connection, and thus in "Stereo" mode you will be able to have a "dual channel" oscilloscope. If we just want only one Channel, either don't connect the other channel or use this connection in "Mono" Mode instead of "Stereo".
3.5 mm jack connection for our Common Man's Oscilloscope ( Solder connection should be like this, channel 1 & 2 are interchangeable)
3.5 mm jack connection for our Common Man's Oscilloscope ( Solder connection should be like this, channel 1 & 2 are interchangeable) 


Analysis Of Waves
Signal is acquired through sound card, processed and sampled inside the sound card and fed to the computer , can be displayed on various sound analyzing tools such as soundcard oscilloscope .

A Snapshot Of "Scope" interface ( Sound card Oscilloscope), aka Common Man Oscilloscope
Or any other sound editing software, that support recording or gathering the data from Line In port of your computer's sound card. Open source software like Audacity can also do it effectively, there you will even get the option to set the sampling rate & the MONO & STEREO mode use of this.

Commercially available oscilloscope has a very high sampling rate, & this oscilloscope it is limited to 96 Khz /24-bit  to  192 khz /32-bit data (maximum sampling rate of sound card) .

If you are a NI LabVIEW user, you can also use this software to create a VI, that will be used to gather the voltage data across the Channels of your oscilloscope.
NI LABVIEW Snapshot of Acquisition of Voltage of Our Common Man Oscilloscope, Through 3.5 mm jack
NI LABVIEW Snapshot of Acquisition of Voltage of Our Common Man Oscilloscope, Through 3.5 mm jack

 Here you can find the option to select your oscilloscope as a MIC. #Channels will give you the options to make your oscilloscope work as in Single or Dual Channel mode. In the figure the Channel 1 of the oscilloscope data is displayed in white colors & Channel 2 in Red colors. You can even control the Duration of the data to be analyzed & required sampling rate too.
After clicking OK, just you have to connect the Output of the "Acquire Sound" Module to a graph display available as an option there.

So we hope that you had a wonderful time reading through this short article, we will be back very soon with some more new stuffs like that...So stay tuned & updated....!
-TEAM Digital iVision Labs!

Standard Resistors & Capicitors Value That You Will Find While Purchasing Them

If you have enough practical experience, of designing(on paper or simulation based) & applying(practically), resistive/capacitive circuits, you might have found that the theoretical value of resistor/capacitor which we have chosen to design, is not actually available in the market.
    
In market only a few set of standard value of resistors/capacitors you will able to find, then in order to implement that circuit that you have designed, you have to make a series/parallel connection from the available options, in order to get desired value.

But most of the time we just have to compromise with the resistor/capacitor value that we have got from there, and we use the available options just to estimate the desired value. 

So why not, design the circuit with a Pre-knowledge of the standard value of resistors/capacitors that you can find in the component shops? That will surely help you to avoid the compromise, on the resistance/capacitance value & more over you will know that what value resistor/capacitor you have to purchase.....

So we at Digital iVision Labs, provide you with 2 tables, which contain some standard value that can be found when you are out for the resistor/capacitor hunt, 


##First list, is for the resistors. 
Here all the values are in Ohms. K for Kilo Ohms & M for Mega ohms.

Standard Resistor Values (±5%)

1.0             10              100            1.0K          10K           100K         1.0M
1.1             11              110            1.1K          11K           110K         1.1M
1.2             12              120            1.2K          12K           120K         1.2M
1.3             13              130            1.3K          13K           130K         1.3M
1.5             15              150            1.5K          15K           150K         1.5M
1.6             16              160            1.6K          16K           160K         1.6M
1.8             18              180            1.8K          18K           180K         1.8M
2.0             20              200            2.0K          20K           200K         2.0M
2.2             22              220            2.2K          22K           220K         2.2M
2.4             24              240            2.4K          24K           240K         2.4M
2.7             27              270            2.7K          27K           270K         2.7M
3.0             30              300            3.0K          30K           300K         3.0M
3.3             33              330            3.3K          33K           330K         3.3M
3.6             36              360            3.6K          36K           360K         3.6M
3.9             39              390            3.9K          39K           390K         3.9M
4.3             43              430            4.3K          43K           430K         4.3M
4.7             47              470            4.7K          47K           470K         4.7M
5.1             51              510            5.1K          51K           510K         5.1M
5.6             56              560            5.6K          56K           560K         5.6M
6.2             62              620            6.2K          62K           620K         6.2M
6.8             68              680            6.8K          68K           680K         6.8M
7.5             75              750            7.5K          75K           750K         7.5M
8.2             82              820            8.2K          82K           820K         8.2M
9.1             91              910            9.1K          91K           910K         9.1M


Second List is for capacitors, that is including Ceramic, Mylar, Electrolytic etc type of capacitors. 
Here all the values are in Farads, with the suffix included. Here, pF id for picofarad & uF is for microfarad

Standard Capacitor Values
(±10%)

10pF          100pF        1000pF      .010uF       .10uF         1.0uF         10uF
12pF          120pF        1200pF      .012uF       .12uF         1.2uF
15pF          150pF        1500pF      .015uF       .15uF         1.5uF
18pF          180pF        1800pF      .018uF       .18uF         1.8uF
22pF          220pF        2200pF      .022uF       .22uF         2.2uF         22uF
27pF          270pF        2700pF      .027uF       .27uF         2.7uF
33pF          330pF        3300pF      .033uF       .33uF         3.3uF         33uF
39pF          390pF        3900pF      .039uF       .39uF         3.9uF
47pF          470pF        4700pF      .047uF       .47uF         4.7uF         47uF
56pF          560pF        5600pF      .056uF       .56uF         5.6uF
68pF          680pF        6800pF      .068uF       .68uF         6.8uF
82pF          820pF        8200pF      .082uF       .82uF         8.2uF
 
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