我想将类型uint16_t
的ADC值存储到32KB uint8_t
,因为我想将数据写入SD卡。目前,我在努力将转换后的16位整数复制到缓冲区中。
我的代码如下:
#define SD_WRITE_BUF_SIZE 32768 //32KB
uint16_t adc_value; // holds the adc Converted value
uint8_t adc_conv_value[2]; // array to store the 8bit conversion of adc_value;
UINT bytesWritten;
int adc_callback_counter = 0;
uint8_t sd_buf_write[SD_WRITE_BUF_SIZE];
int main void
{
Mount_SD_CARD(); // Mount SD Card
Open_SD_CARD_write(); // create file and open for writing
Start_ADC_Conversion(); // Start ADC Conversion;
while (1)
{
if(adc_callback_counter >= (32768/2))
{
write_res = f_write(&myFile, sd_buf_write, SD_WRITE_BUF_SIZE, &bytesWritten);
if(write_res == FR_OK)
{
// Stop ADC
ADC_Stop();
// reset counter
adc_conv_counter = 0;
// close file
f_close(&myFile);
}
}
}
ADC_Conversion_Callback()
{
// convert to 2 8 bit values;
adc_conv_value[0] = (adc_values & 0xFF);
adc_conv_value[1] = (adc_values >> 8) & 0xFF;
// How do I use memcpy to continously copy adc_conv_value to sd_buf_write
memcpy(sd_buf_write, ???, sizeof(??));
// Increment counter;
adc_callback_counter++;
}
在ADC_Conversion_Callback()
函数中,如何连续将adc_conv_value
附加到sd_buf_write
直到后一个数组已满?
答案 0 :(得分:1)
//如何使用memcpy将adc_conv_value连续复制到 sd_buf_write
memcpy(sd_buf_write, ???, sizeof(??));
您可以使用adc_callback_counter
变量,它告诉了memcpy
被调用了多少次。
memcpy((char *)sd_buf_write + (sizeof (adc_conv_value) * adc_callback_counter), adc_conv_value, sizeof(adc_conv_value));
(sizeof (adc_conv_value)* adc_callback_counter)
因为我们每次都复制sizeof (adc_conv_value)
,因此起始位置将是sd_buf_write + (sizeof (adc_conv_value) * adc_callback_counter)