Home Explore Help
Register Sign In
abhinav
/
remote-camera-shutter
1
0
Fork 0
Files Issues 0 Pull Requests 0 Wiki
Branch: master
Branches Tags
remote-camer...
/
NRF24_for_attiny
/
doc
/
nrf24_audio_rx_8pde-example.html

nrf24_audio_rx_8pde-example.html 14 KB
Permalink History Raw

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179 
  1. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    2. 

  2. <html xmlns="http://www.w3.org/1999/xhtml">
    3. 

  3. <head>
    4. 

  4. <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
    5. 

  5. <meta http-equiv="X-UA-Compatible" content="IE=9"/>
    6. 

  6. <meta name="generator" content="Doxygen 1.8.5"/>
    7. 

  7. <title>NRF24: nrf24_audio_rx.pde</title>
    8. 

  8. <link href="tabs.css" rel="stylesheet" type="text/css"/>
    9. 

  9. <script type="text/javascript" src="jquery.js"></script>
    10. 

  10. <script type="text/javascript" src="dynsections.js"></script>
    11. 

  11. <link href="doxygen.css" rel="stylesheet" type="text/css" />
    12. 

  12. </head>
    13. 

  13. <body>
    14. 

  14. <div id="top"><!-- do not remove this div, it is closed by doxygen! -->
    15. 

  15. <div id="titlearea">
    16. 

  16. <table cellspacing="0" cellpadding="0">
    17. 

  17.  <tbody>
    18. 

  18.  <tr style="height: 56px;">
    19. 

  19.   <td style="padding-left: 0.5em;">
    20. 

  20.    <div id="projectname">NRF24
    21. 

  21.    </div>
    22. 

  22.   </td>
    23. 

  23.  </tr>
    24. 

  24.  </tbody>
    25. 

  25. </table>
    26. 

  26. </div>
    27. 

  27. <!-- end header part -->
    28. 

  28. <!-- Generated by Doxygen 1.8.5 -->
    29. 

  29.   <div id="navrow1" class="tabs">
    30. 

  30.     <ul class="tablist">
    31. 

  31.       <li><a href="index.html"><span>Main&#160;Page</span></a></li>
    32. 

  32.       <li><a href="annotated.html"><span>Classes</span></a></li>
    33. 

  33.       <li><a href="files.html"><span>Files</span></a></li>
    34. 

  34.       <li><a href="examples.html"><span>Examples</span></a></li>
    35. 

  35.     </ul>
    36. 

  36.   </div>
    37. 

  37. </div><!-- top -->
    38. 

  38. <div class="header">
    39. 

  39.   <div class="headertitle">
    40. 

  40. <div class="title">nrf24_audio_rx.pde</div>  </div>
    41. 

  41. </div><!--header-->
    42. 

  42. <div class="contents">
    43. 

  43. <p>Example sketch showing how to create an audio digital receiver with the <a class="el" href="classNRF24.html" title="Send and receive addressed, reliable, acknowledged datagrams by nRF24L01. ">NRF24</a> class. Works with the nrf24_audio_tx sample transmitter Connect audio output to pin 6, through a low pass filter consisting of a 1k resistor in series followed by a 0.0033 microfarad capacitor to ground (48kHz filter). The audio quality is poor: dont expect hi-fi! We have to change the PWM frequency to 62 kHz so we can get bandwidth reasonable audio out through the low pass filter Tested on UNO</p>
    44. 

  44. <div class="fragment"><div class="line"><span class="comment">// nrf24_audio_rx.pde</span></div>
    45. 

  45. <div class="line"><span class="comment">// -*- mode: C++ -*-</span></div>
    46. 

  46. <div class="line"><span class="comment">// Example sketch showing how to create an audio digital receiver</span></div>
    47. 

  47. <div class="line"><span class="comment">// with the NRF24 class. </span></div>
    48. 

  48. <div class="line"><span class="comment">// Works with the nrf24_audio_tx sample transmitter</span></div>
    49. 

  49. <div class="line"><span class="comment">// Connect audio output to pin 6, through a low pass filter consisting of a 1k resister and series followed by a </span></div>
    50. 

  50. <div class="line"><span class="comment">// 0.0033 microfarad capacitor to ground (48kHz filter).</span></div>
    51. 

  51. <div class="line"><span class="comment">// The audio quality is poor: dont expect hi-fi!</span></div>
    52. 

  52. <div class="line"><span class="comment">// We have to change the PWM frequency to 62 kHz so we can get bandwidth reasonable </span></div>
    53. 

  53. <div class="line"><span class="comment">// audio out through the low pass filter</span></div>
    54. 

  54. <div class="line"><span class="comment">// Tested on UNO</span></div>
    55. 

  55. <div class="line"></div>
    56. 

  56. <div class="line"><span class="preprocessor">#include &lt;NRF24.h&gt;</span></div>
    57. 

  57. <div class="line"><span class="preprocessor">#include &lt;SPI.h&gt;</span></div>
    58. 

  58. <div class="line"></div>
    59. 

  59. <div class="line"></div>
    60. 

  60. <div class="line"><span class="comment">// Singleton instance of the radio</span></div>
    61. 

  61. <div class="line"><a name="_a0"></a><a class="code" href="classNRF24.html">NRF24</a> nrf24;</div>
    62. 

  62. <div class="line"><span class="comment">// NRF24 nrf24(8, 7); // use this to be electrically compatible with Mirf</span></div>
    63. 

  63. <div class="line"><span class="comment">// NRF24 nrf24(8, 10);// For Leonardo, need explicit SS pin</span></div>
    64. 

  64. <div class="line"><span class="comment"></span></div>
    65. 

  65. <div class="line"><span class="comment">/**</span></div>
    66. 

  66. <div class="line"><span class="comment"> * Divides a given PWM pin frequency by a divisor.</span></div>
    67. 

  67. <div class="line"><span class="comment"> *</span></div>
    68. 

  68. <div class="line"><span class="comment"> * The resulting frequency is equal to the base frequency divided by</span></div>
    69. 

  69. <div class="line"><span class="comment"> * the given divisor:</span></div>
    70. 

  70. <div class="line"><span class="comment"> *   - Base frequencies:</span></div>
    71. 

  71. <div class="line"><span class="comment"> *      o The base frequency for pins 3, 9, 10, and 11 is 31250 Hz.</span></div>
    72. 

  72. <div class="line"><span class="comment"> *      o The base frequency for pins 5 and 6 is 62500 Hz.</span></div>
    73. 

  73. <div class="line"><span class="comment"> *   - Divisors:</span></div>
    74. 

  74. <div class="line"><span class="comment"> *      o The divisors available on pins 5, 6, 9 and 10 are: 1, 8, 64,</span></div>
    75. 

  75. <div class="line"><span class="comment"> *        256, and 1024.</span></div>
    76. 

  76. <div class="line"><span class="comment"> *      o The divisors available on pins 3 and 11 are: 1, 8, 32, 64,</span></div>
    77. 

  77. <div class="line"><span class="comment"> *        128, 256, and 1024.</span></div>
    78. 

  78. <div class="line"><span class="comment"> *</span></div>
    79. 

  79. <div class="line"><span class="comment"> * PWM frequencies are tied together in pairs of pins. If one in a</span></div>
    80. 

  80. <div class="line"><span class="comment"> * pair is changed, the other is also changed to match:</span></div>
    81. 

  81. <div class="line"><span class="comment"> *   - Pins 5 and 6 are paired on timer0</span></div>
    82. 

  82. <div class="line"><span class="comment"> *   - Pins 9 and 10 are paired on timer1</span></div>
    83. 

  83. <div class="line"><span class="comment"> *   - Pins 3 and 11 are paired on timer2</span></div>
    84. 

  84. <div class="line"><span class="comment"> *</span></div>
    85. 

  85. <div class="line"><span class="comment"> * Note that this function will have side effects on anything else</span></div>
    86. 

  86. <div class="line"><span class="comment"> * that uses timers:</span></div>
    87. 

  87. <div class="line"><span class="comment"> *   - Changes on pins 3, 5, 6, or 11 may cause the delay() and</span></div>
    88. 

  88. <div class="line"><span class="comment"> *     millis() functions to stop working. Other timing-related</span></div>
    89. 

  89. <div class="line"><span class="comment"> *     functions may also be affected.</span></div>
    90. 

  90. <div class="line"><span class="comment"> *   - Changes on pins 9 or 10 will cause the Servo library to function</span></div>
    91. 

  91. <div class="line"><span class="comment"> *     incorrectly.</span></div>
    92. 

  92. <div class="line"><span class="comment"> *</span></div>
    93. 

  93. <div class="line"><span class="comment"> * Thanks to macegr of the Arduino forums for his documentation of the</span></div>
    94. 

  94. <div class="line"><span class="comment"> * PWM frequency divisors. His post can be viewed at:</span></div>
    95. 

  95. <div class="line"><span class="comment"> *   http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1235060559/0#4</span></div>
    96. 

  96. <div class="line"><span class="comment"> */</span></div>
    97. 

  97. <div class="line"><span class="keywordtype">void</span> setPwmFrequency(<span class="keywordtype">int</span> pin, <span class="keywordtype">int</span> divisor) {</div>
    98. 

  98. <div class="line">  byte mode;</div>
    99. 

  99. <div class="line">  <span class="keywordflow">if</span>(pin == 5 || pin == 6 || pin == 9 || pin == 10) {</div>
    100. 

  100. <div class="line">    <span class="keywordflow">switch</span>(divisor) {</div>
    101. 

  101. <div class="line">      <span class="keywordflow">case</span> 1: mode = 0x01; <span class="keywordflow">break</span>;</div>
    102. 

  102. <div class="line">      <span class="keywordflow">case</span> 8: mode = 0x02; <span class="keywordflow">break</span>;</div>
    103. 

  103. <div class="line">      <span class="keywordflow">case</span> 64: mode = 0x03; <span class="keywordflow">break</span>;</div>
    104. 

  104. <div class="line">      <span class="keywordflow">case</span> 256: mode = 0x04; <span class="keywordflow">break</span>;</div>
    105. 

  105. <div class="line">      <span class="keywordflow">case</span> 1024: mode = 0x05; <span class="keywordflow">break</span>;</div>
    106. 

  106. <div class="line">      <span class="keywordflow">default</span>: <span class="keywordflow">return</span>;</div>
    107. 

  107. <div class="line">    }</div>
    108. 

  108. <div class="line">    <span class="keywordflow">if</span>(pin == 5 || pin == 6) {</div>
    109. 

  109. <div class="line">      TCCR0B = TCCR0B &amp; 0b11111000 | mode;</div>
    110. 

  110. <div class="line">    } <span class="keywordflow">else</span> {</div>
    111. 

  111. <div class="line">      TCCR1B = TCCR1B &amp; 0b11111000 | mode;</div>
    112. 

  112. <div class="line">    }</div>
    113. 

  113. <div class="line">  } <span class="keywordflow">else</span> <span class="keywordflow">if</span>(pin == 3 || pin == 11) {</div>
    114. 

  114. <div class="line">    <span class="keywordflow">switch</span>(divisor) {</div>
    115. 

  115. <div class="line">      <span class="keywordflow">case</span> 1: mode = 0x01; <span class="keywordflow">break</span>;</div>
    116. 

  116. <div class="line">      <span class="keywordflow">case</span> 8: mode = 0x02; <span class="keywordflow">break</span>;</div>
    117. 

  117. <div class="line">      <span class="keywordflow">case</span> 32: mode = 0x03; <span class="keywordflow">break</span>;</div>
    118. 

  118. <div class="line">      <span class="keywordflow">case</span> 64: mode = 0x04; <span class="keywordflow">break</span>;</div>
    119. 

  119. <div class="line">      <span class="keywordflow">case</span> 128: mode = 0x05; <span class="keywordflow">break</span>;</div>
    120. 

  120. <div class="line">      <span class="keywordflow">case</span> 256: mode = 0x06; <span class="keywordflow">break</span>;</div>
    121. 

  121. <div class="line">      <span class="keywordflow">case</span> 1024: mode = 0x7; <span class="keywordflow">break</span>;</div>
    122. 

  122. <div class="line">      <span class="keywordflow">default</span>: <span class="keywordflow">return</span>;</div>
    123. 

  123. <div class="line">    }</div>
    124. 

  124. <div class="line">    TCCR2B = TCCR2B &amp; 0b11111000 | mode;</div>
    125. 

  125. <div class="line">  }</div>
    126. 

  126. <div class="line">}</div>
    127. 

  127. <div class="line"></div>
    128. 

  128. <div class="line"><span class="keywordtype">void</span> setup() </div>
    129. 

  129. <div class="line">{</div>
    130. 

  130. <div class="line">  Serial.begin(9600);</div>
    131. 

  131. <div class="line">  <span class="keywordflow">while</span> (!Serial) </div>
    132. 

  132. <div class="line">    ; <span class="comment">// wait for serial port to connect. Needed for Leonardo only</span></div>
    133. 

  133. <div class="line">  <span class="keywordflow">if</span> (!nrf24.<a name="a1"></a><a class="code" href="classNRF24.html#a6e98cf508939240c1805245170a995f6">init</a>())</div>
    134. 

  134. <div class="line">    Serial.println(<span class="stringliteral">&quot;NRF24 init failed&quot;</span>);</div>
    135. 

  135. <div class="line">  <span class="keywordflow">if</span> (!nrf24.<a name="a2"></a><a class="code" href="classNRF24.html#a3fa90005f98eb2744a533899f9b7e023">setChannel</a>(1))</div>
    136. 

  136. <div class="line">    Serial.println(<span class="stringliteral">&quot;setChannel failed&quot;</span>);</div>
    137. 

  137. <div class="line">  <span class="keywordflow">if</span> (!nrf24.<a name="a3"></a><a class="code" href="classNRF24.html#ade21e0bd4f92d0dfa45909bbbb0e4b01">setThisAddress</a>((uint8_t*)<span class="stringliteral">&quot;aurx1&quot;</span>, 5))</div>
    138. 

  138. <div class="line">    Serial.println(<span class="stringliteral">&quot;setThisAddress failed&quot;</span>);</div>
    139. 

  139. <div class="line"></div>
    140. 

  140. <div class="line">  <span class="keywordflow">if</span> (!nrf24.<a name="a4"></a><a class="code" href="classNRF24.html#adb2fbd1d1aadaad1e9b268508149b6c8">setPayloadSize</a>(32))</div>
    141. 

  141. <div class="line">    Serial.println(<span class="stringliteral">&quot;setPayloadSize failed&quot;</span>);</div>
    142. 

  142. <div class="line">  <span class="keywordflow">if</span> (!nrf24.<a name="a5"></a><a class="code" href="classNRF24.html#a3453db8390d5be4aa99d8c7fde3062a4">setRF</a>(<a name="a6"></a><a class="code" href="classNRF24.html#a52d7af9188397d4a6f5dab55d4f04742aca0c89dd1b40bdc57b7026d8da54de9a">NRF24::NRF24DataRate2Mbps</a>, <a name="a7"></a><a class="code" href="classNRF24.html#a8386e81a9a4b824ab26e785879684c7eacef1d6c037e276e6dadaff2b6056ec0c">NRF24::NRF24TransmitPower0dBm</a>))</div>
    143. 

  143. <div class="line">    Serial.println(<span class="stringliteral">&quot;setRF failed&quot;</span>);    </div>
    144. 

  144. <div class="line">  <span class="keywordflow">if</span> (!nrf24.<a name="a8"></a><a class="code" href="classNRF24.html#a9e15babbfa487da3425b19c60a93c057">powerUpRx</a>())</div>
    145. 

  145. <div class="line">      Serial.println(<span class="stringliteral">&quot;powerOnRx failed&quot;</span>);    </div>
    146. 

  146. <div class="line">  <span class="comment">// Here we change the PWM frequency so we can render audio with better quality</span></div>
    147. 

  147. <div class="line">  setPwmFrequency(6, 1); <span class="comment">// PWM output on pin 6 is 62 khz</span></div>
    148. 

  148. <div class="line">  Serial.println(<span class="stringliteral">&quot;initialised&quot;</span>);</div>
    149. 

  149. <div class="line">}</div>
    150. 

  150. <div class="line"></div>
    151. 

  151. <div class="line"><span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> count = 0;</div>
    152. 

  152. <div class="line"><span class="keywordtype">void</span> loop()</div>
    153. 

  153. <div class="line">{</div>
    154. 

  154. <div class="line">  uint8_t buf[32];</div>
    155. 

  155. <div class="line">  uint8_t len = <span class="keyword">sizeof</span>(buf);</div>
    156. 

  156. <div class="line"></div>
    157. 

  157. <div class="line">  nrf24.<a name="a9"></a><a class="code" href="classNRF24.html#a5260f3e5eeb911e720290e652f628ab5">waitAvailable</a>();</div>
    158. 

  158. <div class="line">  <span class="keywordflow">if</span> (nrf24.<a name="a10"></a><a class="code" href="classNRF24.html#a12799e0afcb52f2a8cb7418dca9e0eab">recv</a>(buf, &amp;len)) <span class="comment">// 140 microsecs</span></div>
    159. 

  159. <div class="line">  {</div>
    160. 

  160. <div class="line">    uint8_t i;</div>
    161. 

  161. <div class="line">    <span class="keywordflow">for</span> (i = 0; i &lt; 32; i++)</div>
    162. 

  162. <div class="line">    {</div>
    163. 

  163. <div class="line">      analogWrite(6, buf[i]); <span class="comment">// 15 microsecs</span></div>
    164. 

  164. <div class="line">      <span class="comment">// This delay was established experimentally to make sure the</span></div>
    165. 

  165. <div class="line">      <span class="comment">// buffer was exhausted just in time for the next packet to arrive     </span></div>
    166. 

  166. <div class="line">      delayMicroseconds(65);</div>
    167. 

  167. <div class="line">    }</div>
    168. 

  168. <div class="line">  }</div>
    169. 

  169. <div class="line">}</div>
    170. 

  170. <div class="line"></div>
    171. 

  171. </div><!-- fragment --> </div><!-- contents -->
    172. 

  172. <!-- start footer part -->
    173. 

  173. <hr class="footer"/><address class="footer"><small>
    174. 

  174. Generated by &#160;<a href="http://www.doxygen.org/index.html">
    175. 

  175. <img class="footer" src="doxygen.png" alt="doxygen"/>
    176. 

  176. </a> 1.8.5
    177. 

  177. </small></address>
    178. 

  178. </body>
    179. 

  179. </html>
    180.