adipu/TweinStein
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

all

Browse Source
This commit is contained in:
pulipakaa24
2026-06-12 02:55:04 -07:00
commit 30406f4f49
2040 changed files with 571534 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

150
DAC/README.html Normal file
View File

@@ -0,0 +1,150 @@
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html xmlns:v="urn:schemas-microsoft-com:vml"
xmlns:o="urn:schemas-microsoft-com:office:office"
xmlns:w="urn:schemas-microsoft-com:office:word"
xmlns:m="http://schemas.microsoft.com/office/2004/12/omml"
xmlns:st1="urn:schemas-microsoft-com:office:smarttags"
xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type"
content="text/html; charset=windows-1252">
<meta name="ProgId" content="Word.Document">
<meta name="Generator" content="Microsoft Word 14">
<meta name="Originator" content="Microsoft Word 14">
<base target="_parent">
<link rel="Edit-Time-Data" href="index_files/editdata.mso">
<title>DAC</title>
<o:smarttagtype
namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"></o:smarttagtype><o:smarttagtype
namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="PlaceName"></o:smarttagtype>
<o:smarttagtype
namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="PlaceType"></o:smarttagtype>
<link rel="themeData" href="index_files/themedata.thmx">
<link rel="colorSchemeMapping"
href="index_files/colorschememapping.xml">
<style>
</style>
</head>
<body style="background-color: white;" alink="#0000ff" lang="EN-US"
link="blue" vlink="#c40026">
<div class="WordSection1">
<p style="text-align: center;" align="center"><span
style="font-size: 18pt;">DAC</span><br>
<table class="MsoNormalTable"
style="border: 3pt outset ; background: rgb(255, 204, 153) none repeat scroll 0% 50%; -moz-background-clip: initial; -moz-background-origin: initial; -moz-background-inline-policy: initial; width: 100%;"
border="1" cellpadding="0" width="100%">
<tr>
<td>
<p><b><span style="font-size: 18pt;">Readme</b></span>
<br> &nbsp;<br>
This is a C language project that configures
the DAC in a simple software output.
The analog reference of 2.5V is used for the DAC.
In the first main, the DAC output occurs in the main program,
with digital input varying from 0 to 4095.
In the second main, the DAC output is updated within the TimerG0 ISR,
creating a sinusoidal wave.
<br>&nbsp;<br>
The following scope trace shows the DAC output on PA15. The frequency of
the sine wave output is <br><br>
&nbsp;&nbsp;&nbsp;<i>frequency</i> = <i>Interrupt Frequency</i> / <i>Table size</i>
= 200kHz/64 = 3.125kHz</p>
<p class="PictureWide"><span lang="en-US"><img src="DACout_voltage.png"
></span></p>
<p>
The spectrum analyzer shows a 1.058dB peak at 3.123 kHz (signal)
and a -37.16dB peak at 7.024kHz (noise).
We can calculate SNR as 1.058 minus -37.16dB = 38.2dB.
One might expect the SNR of a 12-bit DAC to be 20*log(2^12) = 72dB.
However, without an analog filter, the SNR is limited by the size
of the table, 20*log(64) = 36.1 dB. You can see individual steps in the above
analog trace.
</p>
<p class="PictureWide"><span lang="en-US"><img src="DACout_spectrum.png"
></span></p>
<br>&nbsp;<br>
Derived from Texas Instrument code
<ul>
<li>dac12_fixed_voltage_vref_internal_LP_MSPM0G3507_nortos_ticlang</li>
<li>dac12_fifo_timer_event_LP_MSPM0G3507_nortos_ticlang</li>
<li>timx_timer_mode_periodic_sleep_LP_MSPM0G3507_nortos_ticlang</li>
<li>gpio_toggle_output_LP_MSPM0G3507_nortos_ticlang</li></ul>
</td>
</tr>
</table>
</p>
<table class="MsoNormalTable"
style="border: 3pt outset ; background: rgb(252, 243, 144) none repeat scroll 0% 50%; -moz-background-clip: initial; -moz-background-origin: initial; -moz-background-inline-policy: initial; width: 100%;"
border="1" cellpadding="0" width="100%">
<tbody>
<tr>
<td>
<p><b><span style="font-size: 18pt;">Hardware Required</b></span>
<br>
<ul>
<li>MSPM0G3507 LaunchPad&trade; Development Kit (LP-MSPM0G3507)</li>
</ul>
<b><span style="font-size: 18pt;">Pin assignments</b></span>
<br>
<ul>
<li>Output: PA0 is red LED1, index 0 in IOMUX PINCM table</li>
<li>Analog output: PA15 J3.30 DACout</li>
</ul>
<b><span style="font-size: 18pt;">LaunchPad Jumpers</b></span>
<br>
<ul>
<li>Remove J16 J17 J18: Disconnects light sensor from the microcontroller PA22 PA27 PA26</li>
<li>J5: Connects PB22 to blue LED2</li>
<li>J6: Connects PB26 to red LED2</li>
<li>J7: Connects PB27 to green LED2</li>
</ul>
</p> </td>
</tr>
</tbody>
</table>
</body>
</html>
<p>
Simplified BSD License (FreeBSD License)
Copyright &copy; 2023, Jonathan Valvano, All rights reserved.<br>
&nbsp;<br>
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:<br>
<ol>
<li>Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.</li>
<li>Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.</li></ol>
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.<br>
&nbsp;<br>
The views and conclusions contained in the software and documentation are
those of the authors and should not be interpreted as representing official
policies, either expressed or implied, of the FreeBSD Project.
<br> &nbsp;
</p>
<p>For more information, see <a href="http://users.ece.utexas.edu/~valvano/">
http://users.ece.utexas.edu/~valvano/</a>.
</p>
</div>
</body>
</html>