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首先开启DSP库
然后添加DSP库的头文件
参考armbbs硬汉大佬的数字信号教程，使用matlab设计一个FIR数字滤波器 - #define TEST_LENGTH_SAMPLES 1024 //采样点数
- #define BLOCK_SIZE 1 //调用一次arm_fir_f32处理的采样点个数
- #define NUM_TAPS 29 //滤波器系数个数
- uint32_t blockSize = BLOCK_SIZE;
- uint32_t numBlocks = TEST_LENGTH_SAMPLES/BLOCK_SIZE; //需要调用arm_fir_f32的次数
- static float32_t firStateF32[BLOCK_SIZE + NUM_TAPS - 1]; //状态缓存，大小numTaps + blockSize - 1
- //数字低通滤波器系数 通过matlab命令fadtool获取
- const float32_t firCoeffs32LP[NUM_TAPS] = {
- 0.004408003297, 0.005197565537, 0.007328365929, 0.01079409383, 0.01550024934,
- 0.02126707509, 0.02783845738, 0.03489634395, 0.04207972065, 0.04900695756,
- 0.0552999489, 0.0606084317, 0.06463276595, 0.06714358181, 0.0679968819,
- 0.06714358181, 0.06463276595, 0.0606084317, 0.0552999489, 0.04900695756,
- 0.04207972065, 0.03489634395, 0.02783845738, 0.02126707509, 0.01550024934,
- 0.01079409383, 0.007328365929, 0.005197565537, 0.004408003297
- };
- //数字低通滤波器
- void arm_fir_f32_lp(float32_t *in,float32_t *out)
- {
- arm_fir_instance_f32 S;
- float32_t *inputF32, *outputF32;
- inputF32 = in;
- outputF32 = out;
- arm_fir_init_f32(&S, NUM_TAPS, (float32_t *)&firCoeffs32LP[0], &firStateF32[0], blockSize);
- //FIR滤波，每次处理1个点
- for(int i=0; i < numBlocks; i++)
- {
- arm_fir_f32(&S, inputF32 + (i * blockSize), outputF32 + (i * blockSize), blockSize);
- }
- }
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