【STM32+HAL】与OpenMV通信(串口中断+DMA)
【STM32+HAL】与OpenMV通信。USART2：STM32与OPENMV通信。USART1：STM32与电脑通信。
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一、OpenMV IDE
1、简单数据通信
import time
from pyb import UART
uart = UART(3, 115200, timeout_char=200)
uart.init(115200, bits=8, parity=None, stop=1) # init with given parameters
while True:
FH = bytearray([0xb3,0xb3]) #帧头，控制板接收数据以后判断，转化为字节传送，不能用16进制直接传
uart.write(FH) #写到串口
uart.write("Logan") #写数据
FH = bytearray([0x0d,0x0a]) #结束标志,换行和回车的ascll
uart.write(FH)
time.sleep_ms(1000) #延时
2、多字节数据通信
def send_data(x,y,w,h):
global uart;
uart.write(str(x))
uart.write(bytearray([0x20])) # 发送空格
uart.write(str(y))
uart.write(bytearray([0x20]))
uart.write(str(w))
uart.write(bytearray([0x20]))
uart.write(str(h))
uart.write(bytearray([0x20]))3、寻找最大色块，传递中心点坐标及矩形长宽
import time
import sensor
import math
import image
import ustruct
from pyb import UART
uart = UART(3, 115200, timeout_char=200)
uart.init(115200, bits=8, parity=None, stop=1) # init with given parameters
threshold_index = 4 # 0 for red, 1 for green, 2 for blue
thresholds = [
(30, 100, 15, 127, 15, 127), # generic_red_thresholds
(30, 100, -64, -8, -32, 32), # generic_green_thresholds
(0, 30, 0, 64, -128, 0), # generic_blue_thresholds
(82, 100, 75, -49, -22, 31), # generic_white_thresholds
(21, 83, 32, 65, 31, 63),
]
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)# QVGA的中心坐标：160,120
sensor.skip_frames(time=2000) # 跳过2000毫秒的帧让相机图像在改变相机设置后稳定下来
sensor.set_auto_gain(False) # 必须关闭才能进行颜色跟踪
sensor.set_auto_whitebal(False) # 必须关闭才能进行颜色跟踪
clock = time.clock()
def find_max(blobs):
max_size=0
for blob in blobs:
if blob.pixels() > max_size:
max_blob = blob
max_size = blob.pixels()
return max_blob
def send_data(x,y,w,h):
global uart;
FH = bytearray([0xb3,0xb3]) # 帧头
uart.write(FH) # 写到串口
uart.write(str(x))
uart.write(bytearray([0x20])) # 发送空格
uart.write(str(y))
uart.write(bytearray([0x20]))
uart.write(str(w))
uart.write(bytearray([0x20]))
uart.write(str(h))
uart.write(bytearray([0x20]))
FH = bytearray([0x0d,0x0a]) # 帧尾,换行和回车的ascll
uart.write(FH)
while True:
clock.tick()
img = sensor.snapshot()
blobs = img.find_blobs([thresholds[threshold_index]])
#如果找到了目标颜色
if blobs:
max_blob = find_max(blobs)
cx=max_blob[5]
cy=max_blob[6]
cw=max_blob[2]
ch=max_blob[3]
# 这些值取决于max_blob不是圆形的，否则它们将不稳定.
# 检查max_blob是否显著偏离圆形
if max_blob.elongation() > 0.5:
img.draw_edges(max_blob.min_corners(), color=(255, 0, 0))
img.draw_line(max_blob.major_axis_line(), color=(0, 255, 0))
img.draw_line(max_blob.minor_axis_line(), color=(0, 0, 255))
# 这些值始终是稳定的。
# img.draw_rectangle(max_blob.rect())
img.draw_rectangle(160,120,35,35)
img.draw_cross(cx, cy)
# 注意-max_blob旋转仅限于0-180。
img.draw_keypoints(
[(cx, cy, int(math.degrees(max_blob.rotation())))], size=20
)
send_data(cx,cy,cw,ch) # 发送数据
print(cx,cy,cw,ch)
print(clock.fps())
二、STM32串口中断模式接收
1、初始化
#include "string.h"
#include "stdio.h"
#include "stdlib.h"
#define RXBUFFERSIZE 256
char RxBuffer[RXBUFFERSIZE],rx_buf[RXBUFFERSIZE];
uint8_t aRxBuffer;
uint8_t Uart1_Rx_Cnt = 0;
int flag=0;
printf("Hello World!\r\n");
HAL_Delay(200);
HAL_UART_Receive_IT(&huart2, (uint8_t *)&aRxBuffer, 1);
int fputc(int ch, FILE *f)
{
HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xffff);
HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 0xffff);
return ch;
}
int fgetc(FILE *f)
{
uint8_t ch = 0;
HAL_UART_Receive(&huart1, &ch, 1, 0xffff);
HAL_UART_Receive(&huart2, &ch, 1, 0xffff);
return ch;
}
2、串口回调
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
UNUSED(huart);
if(huart==&huart2){
HAL_GPIO_TogglePin(GPIOF,LED_Pin); //有数据则翻转LED灯
RxBuffer[Uart1_Rx_Cnt] = aRxBuffer;
Uart1_Rx_Cnt++;
if((RxBuffer[Uart1_Rx_Cnt-1] == 0xb3)&&(RxBuffer[Uart1_Rx_Cnt-2] == 0xb3)) flag=1; //帧头判定
else if((RxBuffer[Uart1_Rx_Cnt-2] == 0x0d)&&(RxBuffer[Uart1_Rx_Cnt-1] == 0x0a)) flag=2; //帧尾判定
else flag=0;
switch (flag)
{
case 1:
Uart1_Rx_Cnt = 0;
memset(RxBuffer,0x00,sizeof(RxBuffer));
break;
case 2:
RxBuffer[Uart1_Rx_Cnt-1] = '\0';
RxBuffer[Uart1_Rx_Cnt-2] = '\0';
strcpy(rx_buf,RxBuffer);
printf("%s\r\n",rx_buf);
while(HAL_UART_GetState(&huart2) == HAL_UART_STATE_BUSY_TX);
Uart1_Rx_Cnt = 0;
memset(RxBuffer,0x00,sizeof(RxBuffer));
break;
default:break;
}
HAL_UART_Receive_IT(&huart2, (uint8_t *)&aRxBuffer, 1);
}
}
3、CUBEMX开启串口
USART1：STM32与电脑通信
USART2：STM32与OPENMV通信
四、DMA传输版本
1、main.c
#include "stdio.h"
#include "string.h"
#include "stdlib.h"
#define RXBUFFERSIZE 256
volatile uint8_t recv_end_flag = 0; //接收结束标志位
uint8_t RxBuffer2[RXBUFFERSIZE],rx_buf2[RXBUFFERSIZE];
HAL_UART_Transmit_DMA(&huart1,(uint8_t *)"Hello\r\n",sizeof("Hello\r\n"));
HAL_Delay(200);
__HAL_UART_ENABLE_IT(&huart2, UART_IT_IDLE);
HAL_UART_Receive_DMA(&huart2,RxBuffer2,sizeof(RxBuffer2));2、stm32f4xx_hal.c
extern volatile uint8_t recv_end_flag; //接收结束标志位
extern uint8_t RxBuffer2[RXBUFFERSIZE],rx_buf2[RXBUFFERSIZE];
int cx=0,cy=0;
void USART2_IRQHandler(void)
{
/* USER CODE BEGIN USART2_IRQn 0 */
/* USER CODE END USART2_IRQn 0 */
HAL_UART_IRQHandler(&huart2);
/* USER CODE BEGIN USART2_IRQn 1 */
uint8_t tmp_flag =__HAL_UART_GET_FLAG(&huart2,UART_FLAG_IDLE); //获取IDLE标志位
if((tmp_flag != RESET)) //通过标志位判断接收是否结束
{
recv_end_flag = 1; //置1表明接收结束
__HAL_UART_CLEAR_IDLEFLAG(&huart2); //清除标志位
HAL_UART_DMAStop(&huart2);
strcpy((char *)rx_buf2,(char *)RxBuffer2);
int st=0,cnt_blank=0;
for(int i=0;rx_buf2[i];i++){
if(rx_buf2[i]==' ') {
cnt_blank++;
int temp=0;
for(int j=st;j<i;j++) temp=temp*10+(rx_buf2[j]-'0');
switch (cnt_blank)
{
case 1:cx=temp;st=i+1;break;
case 2:cy=temp;break;
default:break;
}
}
}
printf("%d %d\r\n",cx,cy);
HAL_UART_Receive_DMA(&huart2,RxBuffer2,sizeof(RxBuffer2)); //开启DMA接收，方便下一次接收数据
}
/* USER CODE END USART2_IRQn 1 */
}CUBEMX配置及更多详见【STM32+HAL】DMA应用
五、巨人之肩
六、接线图
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