150 lines
6.0 KiB
HTML
150 lines
6.0 KiB
HTML
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<title>TimerPWM</title>
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<body style="background-color: white;" alink="#0000ff" lang="EN-US"
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link="blue" vlink="#c40026">
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<div class="WordSection1">
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<p style="text-align: center;" align="center"><span
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style="font-size: 18pt;">TimerPWM</span><br>
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<table class="MsoNormalTable"
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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%;"
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border="1" cellpadding="0" width="100%">
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<tr>
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<td>
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<p><b><span style="font-size: 18pt;">Readme</b></span>
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<br> <br>
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This is a C language project that implements two
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PWM outupts using TimerG0.
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Let <i>f</i> be the frequency of the selected clock. The parameters <i>period</i>,
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<i>prescale</i>, <i>duty0</i>,
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and <i>duty1</i> passed into the initialization function.
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The <i>frequency</i> of the PWM outputs will be</p><p>
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<i>frequency</i> = <i>f</i> / (<i>prescale</i>+1) / <i>period</i>
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</p><p>
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The <i>d0 d1</i> duty cycles of the PWM outputs will be</p><p>
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<i>d0</i> = <i>duty0</i> / <i>period</i><br>
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<i>d1</i> = <i>duty1</i> / <i>period</i><br>
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</p><p>
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In this first example, <i>f</i> is 32768 Hz,
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<i>prescale</i> is 0,<i>duty0</i> is 250, <i>duty1</i> is 750 and <i>period</i> is 1000.
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The first figure shows this creates two 32.768Hz PWM outputs with
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25% duty cycle on PA12 and 75% duty cycle on PA13.
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Notice the waves are synchronized, so the rising edges occur at the same time.</p>
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<p class="PictureWide"><span lang="en-US"><img src="PWM_32Hz.png"
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></span></p>
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<p>
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In this second example, <i>f</i> is 48 MHz,
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<i>prescale</i> is 47,<i>duty0</i> is 2500, <i>duty1</i> is 7500 and <i>period</i> is 10000.
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The first figure shows this creates two 10 kHz PWM outputs with
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25% duty cycle on PA12 and 75% duty cycle on PA13.
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</p>
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</p>
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<p class="PictureWide"><span lang="en-US"><img src="PWM_100Hz.png"
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></span></p>
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<p>
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Derived from Texas Instrument code
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<ul>
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<li>timx_timer_mode_pwm_edge_sleep_LP_MSPM0G3507_nortos_ticlang</li>
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</ul>
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</td>
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</tr>
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</table>
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</p>
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<table class="MsoNormalTable"
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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%;"
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border="1" cellpadding="0" width="100%">
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<tbody>
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<tr>
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<td>
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<p><b><span style="font-size: 18pt;">Hardware Required</b></span>
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<br>
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<ul>
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<li>MSPM0G3507 LaunchPad™ Development Kit (LP-MSPM0G3507)</li>
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</ul>
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<b><span style="font-size: 18pt;">Pin assignments</b></span>
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<br>
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<ul>
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<li>Output: PA12 is CCP0 PWM from TimerG0</li>
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<li>Output: PA13 is CCP1 PWM from TimerG0</li>
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</ul>
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<b><span style="font-size: 18pt;">LaunchPad Jumpers</b></span>
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<br>
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<ul>
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<li>Remove J16 J17 J18: Disconnects light sensor from the microcontroller PA22 PA27 PA26</li>
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<li>J5: Connects PB22 to blue LED2</li>
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<li>J6: Connects PB26 to red LED2</li>
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<li>J7: Connects PB27 to green LED2</li>
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</ul>
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</p> </td>
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</tr>
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</tbody>
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</table>
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</body>
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</html>
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<p>
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Simplified BSD License (FreeBSD License)
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Copyright © 2023, Jonathan Valvano, All rights reserved.<br>
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<br>
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Redistribution and use in source and binary forms, with or without modification,
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are permitted provided that the following conditions are met:<br>
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<ol>
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<li>Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.</li>
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<li>Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.</li></ol>
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
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USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.<br>
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<br>
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The views and conclusions contained in the software and documentation are
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those of the authors and should not be interpreted as representing official
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policies, either expressed or implied, of the FreeBSD Project.
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<br>
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</p>
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<p>For more information, see <a href="http://users.ece.utexas.edu/~valvano/">
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http://users.ece.utexas.edu/~valvano/</a>.
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</p>
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