1.2.html 15.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"

<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
    <meta http-equiv="X-UA-Compatible" content="IE=Edge" />
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>The equipment &#8212; eyes17 1.0 documentation</title>
    <link rel="stylesheet" href="_static/sphinxdoc.css" type="text/css" />
    <link rel="stylesheet" href="_static/pygments.css" type="text/css" />
    <script type="text/javascript" id="documentation_options" data-url_root="./" src="_static/documentation_options.js"></script>
    <script type="text/javascript" src="_static/jquery.js"></script>
    <script type="text/javascript" src="_static/underscore.js"></script>
    <script type="text/javascript" src="_static/doctools.js"></script>
    <link rel="index" title="Index" href="genindex.html" />
    <link rel="search" title="Search" href="search.html" />
    <link rel="next" title="Software Installation" href="1.3.html" />
    <link rel="prev" title="Introduction" href="1.1.html" /> 
    <div class="related" role="navigation" aria-label="related navigation">
        <li class="right" style="margin-right: 10px">
          <a href="genindex.html" title="General Index"
        <li class="right" >
          <a href="1.3.html" title="Software Installation"
             accesskey="N">next</a> |</li>
        <li class="right" >
          <a href="1.1.html" title="Introduction"
             accesskey="P">previous</a> |</li>
        <li class="nav-item nav-item-0"><a href="index.html">eyes17 1.0 documentation</a> &#187;</li> 
      <div class="sphinxsidebar" role="navigation" aria-label="main navigation">
        <div class="sphinxsidebarwrapper">
  <h3><a href="index.html">Table Of Contents</a></h3>
<li><a class="reference internal" href="#">The equipment</a><ul>
<li><a class="reference internal" href="#external-connections">External connections</a><ul>
<li><a class="reference internal" href="#outputs">Outputs:</a><ul>
<li><a class="reference internal" href="#constant-current-source-ccs">Constant Current Source (CCS) :</a></li>
<li><a class="reference internal" href="#programmable-voltage-pv1">Programmable Voltage (PV1) :</a></li>
<li><a class="reference internal" href="#programmable-voltage-pv2">Programmable Voltage (PV2) :</a></li>
<li><a class="reference internal" href="#square-wave-sq1">Square Wave SQ1:</a></li>
<li><a class="reference internal" href="#square-wave-sq2">Square Wave SQ2:</a></li>
<li><a class="reference internal" href="#digital-output-od1">Digital Output (OD1) :</a></li>
<li><a class="reference internal" href="#sine-triangular-wave-wg">Sine/Triangular Wave WG:</a></li>
<li><a class="reference internal" href="#inputs">Inputs:</a><ul>
<li><a class="reference internal" href="#capacitance-meter-in1">Capacitance meter IN1:</a></li>
<li><a class="reference internal" href="#frequency-counter-in2">Frequency Counter IN2:</a></li>
<li><a class="reference internal" href="#resistive-sensor-input-sen">Resistive Sensor Input (SEN):</a></li>
<li><a class="reference internal" href="#analog-inputs-a1-a2"><img class="math" src="_images/math/bbc2ff13bad8d262b9cc56f16a664ff4871beaf1.png" alt="\pm16\ V"/> Analog Inputs, A1 &amp; A2:</a></li>
<li><a class="reference internal" href="#analog-input-a3"><img class="math" src="_images/math/a8045cf7990709a0503df23e7cac7cf9fdfac062.png" alt="\pm3.3\ V"/> Analog Input A3:</a></li>
<li><a class="reference internal" href="#microphone-input-mic">Microphone input MIC:</a></li>
<li><a class="reference internal" href="#i2c-sensor-interface">I2C Sensor Interface:</a></li>
<li><a class="reference internal" href="#power-supply"><img class="math" src="_images/math/2201dc802084bb28c4d086972d749820916bfaa6.png" alt="\pm\ 6\ V/10\ mA"/> Power supply:</a></li>
<li><a class="reference internal" href="#accessory-set">1.2.2 Accessory Set</a></li>

  <h4>Previous topic</h4>
  <p class="topless"><a href="1.1.html"
                        title="previous chapter">Introduction</a></p>
  <h4>Next topic</h4>
  <p class="topless"><a href="1.3.html"
                        title="next chapter">Software Installation</a></p>
  <div role="note" aria-label="source link">
    <h3>This Page</h3>
    <ul class="this-page-menu">
      <li><a href="_sources/1.2.rst.txt"
            rel="nofollow">Show Source</a></li>
<div id="searchbox" style="display: none" role="search">
  <h3>Quick search</h3>
    <div class="searchformwrapper">
    <form class="search" action="search.html" method="get">
      <input type="text" name="q" />
      <input type="submit" value="Go" />
      <input type="hidden" name="check_keywords" value="yes" />
      <input type="hidden" name="area" value="default" />
<script type="text/javascript">$('#searchbox').show(0);</script>

    <div class="document">
      <div class="documentwrapper">
        <div class="bodywrapper">
          <div class="body" role="main">
  <div class="section" id="the-equipment">
<h1>The equipment<a class="headerlink" href="#the-equipment" title="Permalink to this headline"></a></h1>
<p>ExpEYES-17 is interfaced and powered by the USB port of the computer,
and it is programmable in Python. It can function as a low frequency
oscilloscope, function generator, programmable voltage source, frequency
counter and data logger. For connecting external signals, it has two
spring loaded terminals blocks, one for output signals and another for
inputs, as shown in figure <a class="reference external" href="#fig:The-ExpEYES-toppanel">1.1↓</a>. The
software can monitor and control the voltages at these terminals. In
order to measure other parameters (like temperature, pressure etc.), we
need to convert them in to electrical signals by using appropriate
sensor elements. The accuracy of the voltage measurements is decided by
the stability of the 3.3V reference used, it is 50ppm per degree
celcius. The gain and offset errors are eliminated by initial
calibration, using a 16bit ADC. Even though our primary objective is to
do experiments, you are advised to read through the brief description of
the equipment given below. The device can be also used as a test
equipment for electrical and electronics engineering experiments.</p>
<p><em>IMPORTANT :</em></p>
<p><em>The external voltages connected to ExpEYES17 must be within the allowed
limits. Inputs A1 and A2 must be within ±16 volts range and Inputs IN1
and IN2 must be in 0 to 3.3V range. Exceeding these limits may result in
damage to the equipment. To measure higher voltages, scale them down
using resistive potential divider networks.</em></p>
<div class="figure" id="fig-e17">
<a class="reference internal image-reference" href="_images/eyes17-panel.jpg"><img alt="_images/eyes17-panel.jpg" src="_images/eyes17-panel.jpg" style="width: 500px;" /></a>
<p>Figure 1.1 The ExpEYES17 top panel showing the external connections.</p>
<div class="section" id="external-connections">
<h2>External connections<a class="headerlink" href="#external-connections" title="Permalink to this headline"></a></h2>
<p>The functions of the external connections briefly explained below. All
the black coulored terminals are at ground potential, all other voltages
are measured with respect to it.</p>
<div class="section" id="outputs">
<h3>Outputs:<a class="headerlink" href="#outputs" title="Permalink to this headline"></a></h3>
<div class="section" id="constant-current-source-ccs">
<h4>Constant Current Source (CCS) :<a class="headerlink" href="#constant-current-source-ccs" title="Permalink to this headline"></a></h4>
<p>The constant current source can be switched ON and OFF under software
control. The nominal value is 1.1 mA but may vary from unit to unit, due
to component tolerances. To measure the exact value, connect an ammeter
from CCS to GND. Another method is to connect a known resistance (~1k)
and measure the voltage drop across it. The load resistor should be less
than 3k for this current source.</p>
<div class="section" id="programmable-voltage-pv1">
<h4>Programmable Voltage (PV1) :<a class="headerlink" href="#programmable-voltage-pv1" title="Permalink to this headline"></a></h4>
<p>Can be set, from software, to any value in the -5V to +5V range. The
resolution is 12 bits, implies a minimum voltage step of around 2.5
<div class="section" id="programmable-voltage-pv2">
<h4>Programmable Voltage (PV2) :<a class="headerlink" href="#programmable-voltage-pv2" title="Permalink to this headline"></a></h4>
<p>Can be set, from software, to any value in the -3.3V to +3.3V range. The
resolution is 12 bits.</p>
<div class="section" id="square-wave-sq1">
<h4>Square Wave SQ1:<a class="headerlink" href="#square-wave-sq1" title="Permalink to this headline"></a></h4>
<p>Output swings from 0 to 5 volts and frequency can be varied 4Hz to
100kHz. All intermediate values of frequency are not possible. The duty
cycle of the output is programmable. Setting frequency to 0Hz will make
the output HIGH and setting it to  − 1 will make it LOW, in both cases
the wave generation is disabled. SQR1 output has a <img class="math" src="_images/math/36dfc0dd6f490d35fa65c29d9013ee762dc718f1.png" alt="100~\Omega"/> <strong>series
resistor</strong> inside so that it can drive LEDs directly.</p>
<div class="section" id="square-wave-sq2">
<h4>Square Wave SQ2:<a class="headerlink" href="#square-wave-sq2" title="Permalink to this headline"></a></h4>
<p>Output swings from 0 to 5 volts and frequency can be varied 4Hz to
100kHz. All intermediate values of frequency are not possible. The duty
cycle of the output is programmable. SQR2 is not available when WG is
<div class="section" id="digital-output-od1">
<h4>Digital Output (OD1) :<a class="headerlink" href="#digital-output-od1" title="Permalink to this headline"></a></h4>
<p>The voltage at OD1 can be set to 0 or 5 volts, using software.</p>
<div class="section" id="sine-triangular-wave-wg">
<h4>Sine/Triangular Wave WG:<a class="headerlink" href="#sine-triangular-wave-wg" title="Permalink to this headline"></a></h4>
<p>Frequency can be varied from 5Hz to 5kHz. The peak value of the
amplitude can be set to 3 volts, 1.0 volt or 80 mV. Shape of the output
waveform is programmable. Using the GUI sine or triangular can be
selected. WG bar is inverted WG.</p>
<div class="section" id="inputs">
<h3>Inputs:<a class="headerlink" href="#inputs" title="Permalink to this headline"></a></h3>
<div class="section" id="capacitance-meter-in1">
<h4>Capacitance meter IN1:<a class="headerlink" href="#capacitance-meter-in1" title="Permalink to this headline"></a></h4>
<p>Capacitance connected between IN1 and Ground can be measured. It works
better for lower capacitance values, upto 10 nanoFarads, results may not
be very accurate beyond that.</p>
<div class="section" id="frequency-counter-in2">
<h4>Frequency Counter IN2:<a class="headerlink" href="#frequency-counter-in2" title="Permalink to this headline"></a></h4>
<p>Capable of measuring frequencies upto several MHz.</p>
<div class="section" id="resistive-sensor-input-sen">
<h4>Resistive Sensor Input (SEN):<a class="headerlink" href="#resistive-sensor-input-sen" title="Permalink to this headline"></a></h4>
<p>This is mainly meant for sensors like Light Dependent Resistor,
Thermistor, Photo-transistor etc. SEN is internally connected to 3.3
volts through a 5.1kΩ resistor.</p>
<div class="section" id="analog-inputs-a1-a2">
<h4><img class="math" src="_images/math/bbc2ff13bad8d262b9cc56f16a664ff4871beaf1.png" alt="\pm16\ V"/> Analog Inputs, A1 &amp; A2:<a class="headerlink" href="#analog-inputs-a1-a2" title="Permalink to this headline"></a></h4>
<p>Can measure voltage within the ±16 volts range. The input voltage range
can be selected from .5V to 16V fullscale. Voltage at these terminals
can be displayed as a function of time, giving the functionality of a
low frequency oscilloscope. The maximum sampling rate is 1 Msps
/channel. Both have an input impedance of 1MΩ .</p>
<div class="section" id="analog-input-a3">
<h4><img class="math" src="_images/math/a8045cf7990709a0503df23e7cac7cf9fdfac062.png" alt="\pm3.3\ V"/> Analog Input A3:<a class="headerlink" href="#analog-input-a3" title="Permalink to this headline"></a></h4>
<p>Can measure voltage within the ±3.3 volts range. The input can be
amplified by connecting a resistor from Rg to Ground, gain
=1 + (Rg)/(10000). This enables displaying very small amplitude signals.
The input impedance of A3 is 10MΩ.</p>
<div class="section" id="microphone-input-mic">
<h4>Microphone input MIC:<a class="headerlink" href="#microphone-input-mic" title="Permalink to this headline"></a></h4>
<p>A condenser microphone can be connected to this terminal and the output
can be captured.</p>
<div class="section" id="i2c-sensor-interface">
<h3>I2C Sensor Interface:<a class="headerlink" href="#i2c-sensor-interface" title="Permalink to this headline"></a></h3>
<p>The four connections (+5V, Ground, SCL and SDA) of the 8 terminal berg
strip supports I2C sensors. The software is capable of recognizing a
large number of commercially available I2C sensors.</p>
<div class="section" id="power-supply">
<h3><img class="math" src="_images/math/2201dc802084bb28c4d086972d749820916bfaa6.png" alt="\pm\ 6\ V/10\ mA"/> Power supply:<a class="headerlink" href="#power-supply" title="Permalink to this headline"></a></h3>
<p>The VR+ and VR- are regulated power outputs. They can supply very little
current, but good enough to power an Op-Amp.</p>
<div class="section" id="accessory-set">
<h2>1.2.2 Accessory Set<a class="headerlink" href="#accessory-set" title="Permalink to this headline"></a></h2>
<p>Some accessories are provided with expEYES.</p>
<ul class="simple">
<li>Pieces of wires, with pin and with crocodile clip.</li>
<li>Condenser microphone with leads.</li>
<li>Inductor Coil (2) : 44SWG wire on 1cm dia bobbin. Around 3000 Turns
(some may have more turns). These coils can be used for studying
inductance, electromagnetic induction etc.</li>
<li>Piezo Electric Discs (2) : Resonant frequency is around 3500 Hz. Can
be energized by WG output or SQR1. Discs are enclosed in a plastic
shell that forms a cavity, that enhances the amplitude of sound
<li>DC Motor : Should be powered by a DC voltage less than 3 volts.</li>
<li>Permanent Magnets : (a) 10mm dia &amp; length (b) 5 mm dia &amp; 10 mm length
(c) Button size magnets(2)</li>
<li>5mm LEDS : RED, BLUE, GREEN, WHITE</li>
<li>Capacitors : 100pF, 0.1uF , 1 uF &amp; 22uF</li>
<li>Inductor : 10 mH / 20Ω,</li>
<li>Resistors : 560Ω, 1kΩ, 2.2kΩ , 10kΩ , 51kΩ and 100 kΩ</li>
<li>Two silicon diodes (1N4148) and one 3.3 volts zener diode</li>
<li>NPN Transistor( 2N2222)</li>

      <div class="clearer"></div>
    <div class="related" role="navigation" aria-label="related navigation">
        <li class="right" style="margin-right: 10px">
          <a href="genindex.html" title="General Index"
        <li class="right" >
          <a href="1.3.html" title="Software Installation"
             >next</a> |</li>
        <li class="right" >
          <a href="1.1.html" title="Introduction"
             >previous</a> |</li>
        <li class="nav-item nav-item-0"><a href="index.html">eyes17 1.0 documentation</a> &#187;</li> 
    <div class="footer" role="contentinfo">
        &#169; Copyright 2018, Jithin B.P..
      Created using <a href="http://sphinx-doc.org/">Sphinx</a> 1.7.5.