发送串行值并转换为浮点数？

Question

我想把串口数据转换成浮点数。

我把串口数据发送给另一个需要浮点值的程序，但我不知道该怎么做。

我发送的值在0到180之间，这些值被接收时是角度，但我需要的是浮点数格式的这些值。我该怎么做呢？

while True:
    while z == True:
        x = x+1
        print x
        if x == 180:
            z = False
    while z == False:
        x = x-1
        print x
        if x == 0:
            z = True


    try:
        envio=ser.write("x")      # write a string
        #print envio
    except Exception, e:
        print "Error en \n\t "+str(e)+"\n"
        ser.close

而x值是在这个脚本中接收到的

ser.open()
degree = ser.read() 

for x in range(1,400,10):
    linea = (432,200)     
    linea_len = 100 
    x = linea[0] + math.cos(math.radians(degree)) * linea_len 
    y = linea[1] + math.sin(math.radians(degree)) * linea_len

但是通过串口发送的x值似乎是二进制的，我需要的是浮点数。

希望你能帮我，谢谢你！！

********************编辑***********************

补充一下问题

发送数据的完整代码

    # -*- coding: utf-8 -*-
"""
Created on Thu Aug 14 15:47:07 2014

@author: Zucra
"""

import serial
ser = serial.Serial()  # open first serial port
ser.port = 2
ser.baudrate = 4800
x=0
z = True
try:
    ser.open()
except Exception, e:
    print "Error en \n\t "+str(e)+"\n"
print ser.name          # check which port was really used

#for i in range(1,1000):
while True:
    while z == True:
        x = x+1
        print x
        if x == 9:
            z = False
    while z == False:
        x = x-1
        print x
        if x == 0:
            z = True      
    try:
        envio=ser.write("x")      # write a string
        #print envio
    except Exception, e:
        print "Error en \n\t "+str(e)+"\n"
        ser.close

接收串口数据的完整代码

import pygame
import sys, serial
from pygame.locals import *
pygame.init()
WIDTH = 865
HEIGHT = 286



ser = serial.Serial()
ser.port = 2
ser.baudrate = 4800


def load_image(filename, transparent=False):
        try: image = pygame.image.load(filename)
        except pygame.error, message:
                raise SystemExit, message
        image = image.convert()
        if transparent:
                color = image.get_at((0,0))
                image.set_colorkey(color, RLEACCEL)
        return image



screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Angulo Pygame")
background_image = load_image('fondo.png')
ser.open()
degree = float(ser.read(1)) 
# se define la letra por defecto
fuente = pygame.font.Font(None, 20)

screen.blit(background_image, (0, 0))




while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            if event.key == K_ESCAPE:
                sys.exit()


#    for event in pygame.event.get():
#        if event.type == pygame.QUIT:
#            sys.exit() 
#        elif event.type == pygame.KEYDOWN:
#            if event.key == K_LEFT:
#                if degree < 180 : 
#                    degree = degree + 1
#            elif event.key == K_RIGHT:
#                if degree > 0:
#                    degree = degree - 1
#            elif event.key == K_ESCAPE:
#                sys.exit()
#                ser.close()              
    for x in range(1,400,10):
        linea = (432,200)     
        linea_len = 100 
        x = linea[0] + math.cos(math.radians(degree)) * linea_len 
        y = linea[1] + math.sin(math.radians(degree)) * linea_len

    # then render the line linea->(x,y)
    screen.blit(background_image, (0, 0))
    texto = "%d" % (degree)
    mensaje = fuente.render(texto, 1, (255, 255, 255))
    screen.blit(mensaje, (450, 185))
    pygame.draw.line(screen, Color("red"), linea, (x,y), 5)
    pygame.display.flip() #vuelca imagen

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发送串行值并转换为浮点数？

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