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MCP4725 模块简介
单通道(1路DA输出)
12位分辨率
I2C 接口(标准,快速,高速支持)
2.7V至5.5V 供电电压
内部EEPROM存储设置
I2C地址可配置(A0)(A1、A2内置,默认为‘00’)
MCP4725 模块地址
芯片内部默认器件地址以‘1100’开头,A2、A1内部下拉为‘00’,A0在默认情况下为‘0’,所以器件地址默认为0x60。
如果两个4725模块同时使用的话,其中一个模块的A0可以改为上拉处理,更改位置见下图。如果焊锡改为ADDR跟VCC相连,器件地址为0x61。
模块跟Arduino Nano的连接
SDA连 Nano的A4;
SCL连Nano的A5;
VCC连Nano的5V;
GND连Nano的GND;
MCP4725模块输出电压编码计算
MCP4725为12为DAC,所以编码范围为0~4096。
输出电压值跟编码的关系如下。
模块的最小分辨率跟供电电压Vdd有关,当5V供电时,最小分辨率为1.22mV,分辨率计算公式为Vdd/4096,如下图所示。
MCP4725模块的正弦波示例代码
/****************************************************************************** MCP4725 Example Waveform Sketch By Malcolm_110 Sept. 17, 2019 This sketch takes data from a lookup table to provide waveforms to be generated by the MCP4725 DAC. #include //Include the Wire library to I2C //This is the I2C Address of the MCP4725, by default (A0 pulled to GND). #define MCP4725_ADDR 0x60 //For devices with A0 pulled HIGH, use 0x61 //Sinewave Tables were generated using this calculator: //http://www.daycounter.com/Calculators/Sine-Generator-Calculator.phtml int lookup = 0;//varaible for navigating through the tables int sintab2[512] = { 2048, 2073, 2098, 2123, 2148, 2174, 2199, 2224, 2249, 2274, 2299, 2324, 2349, 2373, 2398, 2423, 2448, 2472, 2497, 2521, 2546, 2570, 2594, 2618, 2643, 2667, 2690, 2714, 2738, 2762, 2785, 2808, 2832, 2855, 2878, 2901, 2924, 2946, 2969, 2991, 3013, 3036, 3057, 3079, 3101, 3122, 3144, 3165, 3186, 3207, 3227, 3248, 3268, 3288, 3308, 3328, 3347, 3367, 3386, 3405, 3423, 3442, 3460, 3478, 3496, 3514, 3531, 3548, 3565, 3582, 3599, 3615, 3631, 3647, 3663, 3678, 3693, 3708, 3722, 3737, 3751, 3765, 3778, 3792, 3805, 3817, 3830, 3842, 3854, 3866, 3877, 3888, 3899, 3910, 3920, 3930, 3940, 3950, 3959, 3968, 3976, 3985, 3993, 4000, 4008, 4015, 4022, 4028, 4035, 4041, 4046, 4052, 4057, 4061, 4066, 4070, 4074, 4077, 4081, 4084, 4086, 4088, 4090, 4092, 4094, 4095, 4095, 4095, 4095, 4095, 4095, 4095, 4094, 4092, 4090, 4088, 4086, 4084, 4081, 4077, 4074, 4070, 4066, 4061, 4057, 4052, 4046, 4041, 4035, 4028, 4022, 4015, 4008, 4000, 3993, 3985, 3976, 3968, 3959, 3950, 3940, 3930, 3920, 3910, 3899, 3888, 3877, 3866, 3854, 3842, 3830, 3817, 3805, 3792, 3778, 3765, 3751, 3737, 3722, 3708, 3693, 3678, 3663, 3647, 3631, 3615, 3599, 3582, 3565, 3548, 3531, 3514, 3496, 3478, 3460, 3442, 3423, 3405, 3386, 3367, 3347, 3328, 3308, 3288, 3268, 3248, 3227, 3207, 3186, 3165, 3144, 3122, 3101, 3079, 3057, 3036, 3013, 2991, 2969, 2946, 2924, 2901, 2878, 2855, 2832, 2808, 2785, 2762, 2738, 2714, 2690, 2667, 2643, 2618, 2594, 2570, 2546, 2521, 2497, 2472, 2448, 2423, 2398, 2373, 2349, 2324, 2299, 2274, 2249, 2224, 2199, 2174, 2148, 2123, 2098, 2073, 2048, 2023, 1998, 1973, 1948, 1922, 1897, 1872, 1847, 1822, 1797, 1772, 1747, 1723, 1698, 1673, 1648, 1624, 1599, 1575, 1550, 1526, 1502, 1478, 1453, 1429, 1406, 1382, 1358, 1334, 1311, 1288, 1264, 1241, 1218, 1195, 1172, 1150, 1127, 1105, 1083, 1060, 1039, 1017, 995, 974, 952, 931, 910, 889, 869, 848, 828, 808, 788, 768, 749, 729, 710, 691, 673, 654, 636, 618, 600, 582, 565, 548, 531, 514, 497, 481, 465, 449, 433, 418, 403, 388, 374, 359, 345, 331, 318, 304, 291, 279, 266, 254, 242, 230, 219, 208, 197, 186, 176, 166, 156, 146, 137, 128, 120, 111, 103, 96, 88, 81, 74, 68, 61, 55, 50, 44, 39, 35, 30, 26, 22, 19, 15, 12, 10, 8, 6, 4, 2, 1, 1, 0, 0, 0, 1, 1, 2, 4, 6, 8, 10, 12, 15, 19, 22, 26, 30, 35, 39, 44, 50, 55, 61, 68, 74, 81, 88, 96, 103, 111, 120, 128, 137, 146, 156, 166, 176, 186, 197, 208, 219, 230, 242, 254, 266, 279, 291, 304, 318, 331, 345, 359, 374, 388, 403, 418, 433, 449, 465, 481, 497, 514, 531, 548, 565, 582, 600, 618, 636, 654, 673, 691, 710, 729, 749, 768, 788, 808, 828, 848, 869, 889, 910, 931, 952, 974, 995, 1017, 1039, 1060, 1083, 1105, 1127, 1150, 1172, 1195, 1218, 1241, 1264, 1288, 1311, 1334, 1358, 1382, 1406, 1429, 1453, 1478, 1502, 1526, 1550, 1575, 1599, 1624, 1648, 1673, 1698, 1723, 1747, 1772, 1797, 1822, 1847, 1872, 1897, 1922, 1948, 1973, 1998, 2023 }; void setup() { Wire.begin(); } //--------------------------------------------------- void loop() { Wire.beginTransmission(MCP4725_ADDR); Wire.write(64); // cmd to update the DAC Wire.write(sintab2[lookup] >> 4); // the 8 most significant bits... Wire.write((sintab2[lookup] & 15) << 4); // the 4 least significant bits... Wire.endTransmission(); lookup = (lookup + 1) & 511; } 波形图如下图。
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2021-9-27 15:53:06
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