2019-07-14
线插在板子上方
received_frame_data函数调用频率
每隔46-47mm被调用一次，即0.047s被调用一次
该函数的调用频率为21.2765Hz左右
而里面有250个sample，不知道是啥意思
void received_frame_data(void* context,
int32_t protocol_handle,
uint8_t endpoint,
const Frame_Info_t* frame_info)
{
nowTime = GetTickCount();
timeElapsed = nowTime - lastTime;
printf("%d\n", timeElapsed);
lastTime = nowTime;
}
GUI
每个Frame：
1 chirp
250 samples
最小时长 45.608 ms
这与刚才的统计是一致的
Frame_Info
sample_data //获取到的数据的buffer
frame_number = 104 //不知道为啥一直是104
num_chirps = 1 //这一frame里有多少chirp
num_rx_antennas = 1 //每个chirp获取到 1个 RX 信号（一个天线）
num_samples_per_chirp = 250 //一个chirp里250个sample
rx_mask =1 //标记哪个antenna 被用来获取数据
adc_resolution = 12 //The ADC resolution（分辨率） of the data in sample_data
interleaved_rx =0 //不同天线的数据存在连续存储单元内，每个block存一个天线的数据
data_format = 1 // I和Q数据存在分开的block中
typedef struct
{
const float* sample_data; /**< The buffer containing the
radar data */
uint32_t frame_number; /**< The running number of the
data frame. The frame
counter is, reset every time
\ref ep_radar_base_set_automatic_frame_trigger
is called. If automatic
frame trigger is not active,
the frame counter may not
work, and this could be 0.
*/
uint32_t num_chirps; /**< The number of chirps in this
frame. */
uint8_t num_rx_antennas; /**< The number of RX signals
that have been acquired with
each chirp. */
uint32_t num_samples_per_chirp; /**< The number of samples
acquired in each chirp for
each enabled RX antenna. */
uint8_t rx_mask; /**< Each antenna is reperesnted
by a bit in this mask. If
the bit is set, the
according RX antenna was
used to capture data in this
frame. */
uint8_t adc_resolution; /**< The ADC resolution of the
data in sample_data. */
uint8_t interleaved_rx; /**< If this is 0, the radar data
of multiple RX antennas is
stored in consecutive data
blocks, where each block
holds data of one antenna.
If this is non-zero, the
radar data of multiple RX
antennas is stored in one
data block, where for each
point in time the samples
from all RX antennas are
stored consecutively before
the data of the next point
in time follows. */
Rx_Data_Format_t data_format; /**< This indicates if the data
is pDataBuffer is real or
complex, and if complex data
is interleaved. */
} Frame_Info_t;
data format = 1,说明 I和Q存在分开的数据单元内
解决办法：
文档：ComLib_C_Interface.pdf
frame_start = &sample_data[
CHIRP_NUMBER * //?
num_rx_antennas * //1
num_samples_per_chirp */250
((data_format == RADAR_RX_DATA_REAL)? 1 : 2)]; //2
师姐，现在确认了：
- 每一个Frame中有一个chirp
- 每个chirp中有250个sample（I信号和Q信号各250个）
- 每个Frame对应时间为46-47ms，故每秒约21个frame （GUI中称min frame 45.608ms ，46-47ms是上位机实测的结果，很接近，故应该没问题）
- 每个chirp时间为1500us（GUI和上位机代码中均有提及）
此时，GUI输出文件中却说采样率为166666，我想是不是这两个采样率定义不同呢？
166666可能指的是模数转换的采样率，即模拟信号每秒采样166666次，然后转换为数字信号
转换结果是一个一个的frame，每个frame的时间约为46ms
而我们一直尝试计算的是已经获得的数字信号（I信号和Q信号）每秒有多少组，这样的话板子默认配置是21左右
理论上“每秒获得的数字信号组数”，即使修改下位机代码，也不太可能直接从21上升到几千；而当前的21，作为这块板子的默认配置，应该也是很OK的
且如果用距离反映呼吸信号的话，每秒21个距离数据应该也足够了
所以师姐要求的上千的采样率的定义是什么呢？是用于算法建模的数据每秒要有上千个，还是硬件获取原始模拟数据时的采样率呢？
如果现在的频率OK的话，我们可以约定一个输出格式，我按照这个格式把结果输出到本地，师姐就可以直接用了
