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4 - Tone Frequency
The piezo_tone structure is filled and passed to the function, and is used both to set the frequency of the note and its duration. The first value, tone, can be any of 256 possible values that can range from 64 hertz to over 8 kilohertz (and silence), as the table shows:| Tone Number and Frequency Values (in hertz) for piezo_tone Structure | |||||||||||||||
| 0 | (silence) | 1 | 8,192.0 | 2 | 5,461.3 | 3 | 4,096.0 | 4 | 3,276.8 | 5 | 2,730.7 | 6 | 2,340.6 | 7 | 2,048.0 |
| 8 | 1,820.4 | 9 | 1,638.4 | 10 | 1,489.5 | 11 | 1,365.3 | 12 | 1,260.3 | 13 | 1,170.3 | 14 | 1,092.3 | 15 | 1,024.0 |
| 16 | 963.8 | 17 | 910.2 | 18 | 862.3 | 19 | 819.2 | 20 | 780.2 | 21 | 744.7 | 22 | 712.3 | 23 | 682.7 |
| 24 | 655.4 | 25 | 630.2 | 26 | 606.8 | 27 | 585.1 | 28 | 565.0 | 29 | 546.1 | 30 | 528.5 | 31 | 512.0 |
| 32 | 496.5 | 33 | 481.9 | 34 | 468.1 | 35 | 455.1 | 36 | 442.8 | 37 | 431.2 | 38 | 420.1 | 39 | 409.6 |
| 40 | 399.6 | 41 | 390.1 | 42 | 381.0 | 43 | 372.4 | 44 | 364.1 | 45 | 356.2 | 46 | 348.6 | 47 | 341.3 |
| 48 | 334.4 | 49 | 327.7 | 50 | 321.3 | 51 | 315.1 | 52 | 309.1 | 53 | 303.4 | 54 | 297.9 | 55 | 292.6 |
| 56 | 287.4 | 57 | 282.5 | 58 | 277.7 | 59 | 273.1 | 60 | 268.6 | 61 | 264.3 | 62 | 260.1 | 63 | 256.0 |
| 64 | 252.1 | 65 | 248.2 | 66 | 244.5 | 67 | 240.9 | 68 | 237.4 | 69 | 234.1 | 70 | 230.8 | 71 | 227.6 |
| 72 | 224.4 | 73 | 221.4 | 74 | 218.5 | 75 | 215.6 | 76 | 212.8 | 77 | 210.1 | 78 | 207.4 | 79 | 204.8 |
| 80 | 202.3 | 81 | 199.8 | 82 | 197.4 | 83 | 195.0 | 84 | 192.8 | 85 | 190.5 | 86 | 188.3 | 87 | 186.2 |
| 88 | 184.1 | 89 | 182.0 | 90 | 180.0 | 91 | 178.1 | 92 | 176.2 | 93 | 174.3 | 94 | 172.5 | 95 | 170.7 |
| 96 | 168.9 | 97 | 167.2 | 98 | 165.5 | 99 | 163.8 | 100 | 162.2 | 101 | 160.6 | 102 | 159.1 | 103 | 157.5 |
| 104 | 156.0 | 105 | 154.6 | 106 | 153.1 | 107 | 151.7 | 108 | 150.3 | 109 | 148.9 | 110 | 147.6 | 111 | 146.3 |
| 112 | 145.0 | 113 | 143.7 | 114 | 142.5 | 115 | 141.2 | 116 | 140.0 | 117 | 138.8 | 118 | 137.7 | 119 | 136.5 |
| 120 | 135.4 | 121 | 134.3 | 122 | 133.2 | 123 | 132.1 | 124 | 131.1 | 125 | 130.0 | 126 | 129.0 | 127 | 128.0 |
| 128 | 127.0 | 129 | 126.0 | 130 | 125.1 | 131 | 124.1 | 132 | 123.2 | 133 | 122.3 | 134 | 121.4 | 135 | 120.5 |
| 136 | 119.6 | 137 | 118.7 | 138 | 117.9 | 139 | 117.0 | 140 | 116.2 | 141 | 115.4 | 142 | 114.6 | 143 | 113.8 |
| 144 | 113.0 | 145 | 112.2 | 146 | 111.5 | 147 | 110.7 | 148 | 110.0 | 149 | 109.2 | 150 | 108.5 | 151 | 107.8 |
| 152 | 107.1 | 153 | 106.4 | 154 | 105.7 | 155 | 105.0 | 156 | 104.4 | 157 | 103.7 | 158 | 103.0 | 159 | 102.4 |
| 160 | 101.8 | 161 | 101.1 | 162 | 100.5 | 163 | 99.9 | 164 | 99.3 | 165 | 98.7 | 166 | 98.1 | 167 | 97.5 |
| 168 | 96.9 | 169 | 96.4 | 170 | 95.8 | 171 | 95.3 | 172 | 94.7 | 173 | 94.2 | 174 | 93.6 | 175 | 93.1 |
| 176 | 92.6 | 177 | 92.0 | 178 | 91.5 | 179 | 91.0 | 180 | 90.5 | 181 | 90.0 | 182 | 89.5 | 183 | 89.0 |
| 184 | 88.6 | 185 | 88.1 | 186 | 87.6 | 187 | 87.1 | 188 | 86.7 | 189 | 86.2 | 190 | 85.8 | 191 | 85.3 |
| 192 | 84.9 | 193 | 84.5 | 194 | 84.0 | 195 | 83.6 | 196 | 83.2 | 197 | 82.7 | 198 | 82.3 | 199 | 81.9 |
| 200 | 81.5 | 201 | 81.1 | 202 | 80.7 | 203 | 80.3 | 204 | 79.9 | 205 | 79.5 | 206 | 79.1 | 207 | 78.8 |
| 208 | 78.4 | 209 | 78.0 | 210 | 77.6 | 211 | 77.3 | 212 | 76.9 | 213 | 76.6 | 214 | 76.2 | 215 | 75.9 |
| 216 | 75.5 | 217 | 75.2 | 218 | 74.8 | 219 | 74.5 | 220 | 74.1 | 221 | 73.8 | 222 | 73.5 | 223 | 73.1 |
| 224 | 72.8 | 225 | 72.5 | 226 | 72.2 | 227 | 71.9 | 228 | 71.5 | 229 | 71.2 | 230 | 70.9 | 231 | 70.6 |
| 232 | 70.3 | 233 | 70.0 | 234 | 69.7 | 235 | 69.4 | 236 | 69.1 | 237 | 68.8 | 238 | 68.6 | 239 | 68.3 |
| 240 | 68.0 | 241 | 67.7 | 242 | 67.4 | 243 | 67.1 | 244 | 66.9 | 245 | 66.6 | 246 | 66.3 | 247 | 66.1 |
| 248 | 65.8 | 249 | 65.5 | 250 | 65.3 | 251 | 65.0 | 252 | 64.8 | 253 | 64.5 | 254 | 64.3 | 255 | 64.0 |
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