low speed avr oscilloscope.htm

采用AVR单片机制作的低成本LCD示波器资料和源码

                  style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%">Frequency 
                  measurement</P>
                  <P 
                  style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%">Voltage 
                  input</P>
                  <P 
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                  supply</P>
                  <P 
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                  Display Crystal</P>
                  <P 
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                  display area</P>
                  <P 
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                  trigger</P></TD>
                <TD vAlign=top width=229 height=155>
                  <P 
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                  to 5 kHz (square wave)</P>
                  <P 
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                  AC / 30V DC</P>
                  <P 
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                  DC</P>
                  <P 
                  style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%">128x64 
                  pixels</P>
                  <P 
                  style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%">100x64 
                  pixels</P></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
      <P>&nbsp;</P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=justify><B>Introduction</B></P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=justify>&nbsp;</P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=justify>A few months ago as I was surfing on the net, I saw an 
      oscilloscope based on PIC18F2550 microcontroller and a KS0108 controller 
      based graphical LCD. That was <A 
      href="http://www.semifluid.com/?p=29">Steven Cholewiak's web site</A>. I 
      had never seen before so amazing microcontroller-only oscilloscope. That 
      was realy impressive circuit, so I decided to design something like that 
      but in C language instead of assembly that I was using all those years. 
      The best solution for me was the WinAVR as it bases on open source AVR-GNU 
      compiler and it works perfect with AVR studio 4. The graphics library that 
      I used, is made by me specific for this project. It's not for general use. 
      If you want to include it to your codes, you have to convet it as you need 
      to. The maximum signal speed who can show up this oscilloscope is 5 kHz in 
      square signal. For other signals (sine or triangle) the frequency is lower 
      ( almost 1 kHz) for having clear view of the signal.</P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=justify>&nbsp;</P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=center><A 
      href="http://www.serasidis.gr/circuits/AVR_oscilloscope/images/SCHEMATIC.GIF" 
      target=_blank><IMG height=466 
      src="Low%20speed%20AVR%20oscilloscope_files/SCHEMATIC_s.gif" width=640 
      border=1></A></P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=center>Schematic of the circuit (click to enlarge)</P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=center>&nbsp;</P>
      <P align=justify><B>Description</B></P>
      <P align=justify>The operating voltage of the circuit is 12V DC. By this 
      voltage, the power supply is producing 2 voltages. +8.2V for IC1 and +5V 
      for IC2 and IC3. This circuit can measure from +2.5V to -2.5V or from 0 to 
      +5V dependent by S1 position (AC or DC input). By using probe with 1:10 
      division you can measure almost 10 times higher voltages. 
      Moreover,&nbsp;with S2 you can make an extra division by 2 the input 
      voltage. </P>
      <P align=justify>&nbsp;</P>
      <P align=justify><B>Calibrations</B></P>
      <P align=justify>The only 2 things you have to calibrate is the LCD 
      contrast trimmer P2 and the P1, to move the beam at the center of the LCD. 
      To do that, apply only the power supply to the circuit and adjust the P2 
      up to the point you will see clear&nbsp;the appeared pixels on the screen. 
      Then, adjust the P1 up to the point the beam is moved at the middle of the 
      LCD (at the horizontal line of the cross). </P>
      <P>&nbsp;</P>
      <P><B>Usage</B></P>
      <P align=justify>You can move the beam up or down the screen by pressing 
      the buttons S8 or&nbsp;S4 correspondingly to measure the voltage of the 
      signal. 1 volt is taking up&nbsp;1 square height. With S7 and S3 you can 
      increase or decrease the measurement speed. This oscilloscope has an 
      automatic trigger. That means, if you have a continuous signal (ex a 
      triagle waveform) the auto trigger will work perfect. If your signal is 
      not stable (ex a serial transmittion) you can freeze the screen by 
      pressing&nbsp;S6 switch. At his case you can get&nbsp;a snapshoot of your 
      measurment signal. By the time you release the S6, the snapshoot will 
      end.</P>
      <TABLE cellSpacing=0 cellPadding=0 width=696 align=center>
        <TBODY>
        <TR>
          <TD width=340>
            <P align=center><IMG height=507 
            src="Low%20speed%20AVR%20oscilloscope_files/pcb_101x160mm.jpg" 
            width=320 border=1></P></TD>
          <TD width=340>
            <P align=center><IMG height=507 
            src="Low%20speed%20AVR%20oscilloscope_files/components.jpg" 
            width=320 border=1></P></TD></TR></TBODY></TABLE>
      <P align=center>PCB (101x160mm) and components placing</P>
      <P 
      style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%">&nbsp;</P>
      <TABLE cellSpacing=0 borderColorDark=white cellPadding=0 width=685 
      align=center borderColorLight=black>
        <TBODY>
        <TR>
          <TD width=62>
            <P align=center><A 
            href="http://www.serasidis.gr/circuits/AVR_oscilloscope/AVR_oscilloscope.zip"><IMG 
            height=32 src="Low%20speed%20AVR%20oscilloscope_files/download.gif" 
            width=32 border=0></A></P></TD>
          <TD width=613>
            <P align=left><A 
            href="http://www.serasidis.gr/circuits/AVR_oscilloscope/AVR_oscilloscope.zip">Download 
            the source code, hex, schematic and PCB of AVR 
          oscilloscope.</A></P></TD></TR></TBODY></TABLE>
      <P>&nbsp;</P>
      <P align=center>
      <OBJECT id=revvervideoa17743d6aebf486ece24053f35e1aa23 
      type=application/x-shockwave-flash height=392 width=480 
      data=http://flash.revver.com/player/1.0/player.swf?mediaId=532261&amp;affiliateId=138584>
                                                                                 
                           <embed type="application/x-shockwave-flash" 
      src="http://flash.revver.com/player/1.0/player.swf?mediaId=532261&affiliateId=138584" 
      pluginspage="http://www.macromedia.com/go/getflashplayer" 
      allowScriptAccess="always" flashvars="allowFullScreen=true" 
      allowfullscreen="true" height="392" width="480"></embed></OBJECT></P>
      <P align=center></P>
      <P align=center></P>
      <P align=center>Click Play to see AVR oscilloscope in action</P>
      <P>&nbsp;</P>
      <P style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 100%" 
      align=center>&nbsp;</P>
      <P align=center><FONT color=#990033><B>Created and published by Vasilis 
      Serasidis at 01.dec.2007</B></FONT></P>
      <P>&nbsp;</P></TD></TR></TBODY></TABLE><!--Namo WebEditor Data 4.0
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