@yuan openmv的上位机是可以打印出来有几个框，但是单片机接回来的数据是00 30 00
下面是单片机的主函数代码
void macUSART_INT_FUN(void)
{
static uint16_t usRxCount = 0;

if(USART_GetITStatus( macUSARTx, USART_IT_RXNE ) != RESET)
{			
	ucTemp = USART_ReceiveData( macUSARTx );
	/* 遇到换行字符，认为接收到一个命令 */
		Usart_SendStr_length( macUSARTx, ucaRxBuf, usRxCount );
		a = ucaRxBuf[24];
		printf("%d",a);
		usRxCount = 0;
}
	else
	{
		ucaRxBuf[usRxCount++] = ucTemp;
	}

}

int main(void)
{
// /* USART1 配置模式为 115200 8-N-1，中断接收 */
USARTx_Config();
NVIC_Configuration();

Usart_SendString( macUSARTx, "这是一个串口中断接收回显实验\n" );
Usart_SendString( macUSARTx, "输入数据并以回车键结束\n" );

}

@yuan import sensor, time, image, pyb,lcd
from pyb import UART
led = pyb.LED(3)
sensor.reset()
sensor.set_contrast(1)
sensor.set_gainceiling(16)
sensor.set_framesize(sensor.HQVGA)
sensor.set_pixformat(sensor.GRAYSCALE)
face_cascade = image.HaarCascade("frontalface", stages=25)
uart = UART(3,19200)
print(face_cascade)
clock = time.clock()
lcd.init() # Initialize the lcd screen.
while (True):
clock.tick()
img = sensor.snapshot()
objects = img.find_features(face_cascade, threshold=0.75, scale_factor=1.25)
for a in objects:
img.draw_rectangle(a)
time.sleep(2000)
uart.write("%s",a[2])
time.sleep(1000)

print(clock.fps())

lcd.display(img) # Take a picture and display the image.

这是代码，我要把检测到的人脸个数传送给单片机

@yuan 不能直接print(a)

import sensor, time, image, pyb,lcd
from pyb import UART
led = pyb.LED(3)
sensor.reset()
sensor.set_contrast(1)
sensor.set_gainceiling(16)
sensor.set_framesize(sensor.HQVGA)
sensor.set_pixformat(sensor.GRAYSCALE)
face_cascade = image.HaarCascade("frontalface", stages=25)
uart = UART(3,19200)
print(face_cascade)
clock = time.clock()
lcd.init() # Initialize the lcd screen.
while (True):
    clock.tick()
    img = sensor.snapshot()
    objects = img.find_features(face_cascade, threshold=0.75, scale_factor=1.25)
    for a in objects:
        img.draw_rectangle(a)
        time.sleep(2000)
              uart.write("%s",a[2])
              time.sleep(1000)请在这里粘贴代码