串口数字显示出错

_xiaohuohu_

# Blob Detection and uart transport
import sensor, image, time
from pyb import UART
import json
# For color tracking to work really well you should ideally be in a very, very,
# very, controlled enviroment where the lighting is constant...
yellow_threshold   = (65, 100, -10, 6, 24, 51)
# You may need to tweak the above settings for tracking green things...
# Select an area in the Framebuffer to copy the color settings.

sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.RGB565) # use RGB565.
sensor.set_framesize(sensor.QQVGA) # use QQVGA for speed.
sensor.skip_frames(10) # Let new settings take affect.
sensor.set_auto_whitebal(False) # turn this off.
clock = time.clock() # Tracks FPS.

uart = UART(3, 115200)
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

while(True):
    img = sensor.snapshot() # Take a picture and return the image.

    blobs = img.find_blobs([yellow_threshold])
    if blobs:
        max_blob=find_max(blobs)
        print('sum :', len(blobs))
        img.draw_rectangle(max_blob.rect())
        img.draw_cross(max_blob.cx(), max_blob.cy())

        output_str="[%d,%d]" % (max_blob.cx(),max_blob.cy()) #方式1
        #output_str=json.dumps([max_blob.cx(),max_blob.cy()]) #方式2
        print('you send:',output_str)
        #uart.write(output_str+'\r\n')
        uart.writechar(max_blob.cx()) #发送数字
        uart.writechar(max_blob.cy())![0_1531979493507_QQ图片20180719135118.png](https://fcdn.singtown.com/047cea61-1237-4943-8b39-d45b28f57a0d.png) 
    else:
        print('not found!')

0_1531979502427_QQ图片20180719135045.png 0_1531979506991_QQ图片20180719134935.png

检查了一下没有什么错误，波特率也是对的。而且传递字符的 .write可以正常传递，可以.writethar就传递不了数字，显示乱码，这是什么问题求大神指教

kidswong999

writechar 发送的是ascii的二进制，比如writechar(65)或者writechar(0x41)，发送的就是'A',

既然你用ascii显示，那么，就应该用write('123')或者write(str(123))，这样就发送了'123'这个字符串。