#! /usr/bin/python
#coding=utf-8

from __future__ import division
import serial
import sys
import pylab
import time
import numpy


class communication(serial.Serial):
    def __init__(self, *args, **kwargs):
        #Asegura que el timeout tenga un valor rasonable
        timeout = kwargs.get('timeout',0.1)
        if timeout < 0.01: timeout = 0.1
        kwargs['timeout'] = timeout
        serial.Serial.__init__(self, *args, **kwargs)
        self.buf = ''

    def readline(self, timeout=1):
        """timeout en segundos es el máximo tiempo que debe esperar para una trama completa"""
        tries = 0
        while 1:
            self.buf += self.read(512)
            pos = self.buf.find('\n')
            if pos > 0:
                line, self.buf = self.buf[:pos+1], self.buf[pos+1:]
                return line
            tries += 1
            if tries * self.timeout > timeout:
                break
        line, self.buf = self.buf, ''
        return line

    def readlines(self, sizehint=None, timeout=1):
        """Lee todas las tramas que hay disponibles. Aborta después del timeout
        o cuando no hay mas datos."""
        lines = []
        while 1:
            line = self.readline(timeout=timeout)
            if line:
                lines.append(line)
            if not line:# or line[-1:] != '\n':
                break
        return lines

    def send_cmd(self, dato):
        if not dato.endswith('\n'):
            dato += '\n'
        self.write(dato)

    def get_trace(self):
        self.send_cmd(':TRAC:FORMAT ASCII')
        time.sleep(0.1)
        self.send_cmd(':TRAC:DATA?')
        return self.readline(8).strip()

    def get_time_scale(self):
        s.send_cmd(':HOR:MAIN:SCAL?')
        return s.readline().strip()

    def get_amplitud_scale(self, channel="1"):
        s.send_cmd(':CHAN%s:SCAL?' % channel)
        return s.readline().strip()



if __name__=='__main__':
    if len(sys.argv) <= 2:
        print """
Uso: python %s /dev/ttyUSB0 filename""" % sys.argv[0]
        sys.exit(0)
    PORT = sys.argv[1]
    BAUDRATE = 115200
    s = communication(PORT, BAUDRATE)
    s.flush()
    data = s.get_trace()
    fh_out = open("%s.txt" % sys.argv[2], 'w')
    fh_out.write(data)
    fh_out.close()
    data = data.split(',')
    data = numpy.asarray(data, numpy.float32)
    cant_ptos = len(data)
    axis_t = numpy.arange(cant_ptos)
    time_scale = s.get_time_scale()
    time_scale_float = float(time_scale)
    #axis_t = axis_t * time_scale_float * 10
    t_por_pto = (10*time_scale_float)/cant_ptos
    axis_t = axis_t * t_por_pto

    pylab.xlabel('%s Tiempo/Div' % time_scale)
    pylab.ylabel('%s Voltage/Div' % s.get_amplitud_scale())
    pylab.title('%s' % sys.argv[2])
    pylab.grid(True)
    pylab.plot(axis_t, data)
    #print numpy.arange(0, 10*time_scale_float, time_scale_float)
    pylab.xticks(numpy.arange(0, 10*time_scale_float, time_scale_float))
    #pylab.xticks(numpy.arange(0, 10*s.get_time_scale(), s.get_time_scale()))
    #pylab.yticks(numpy.arange(0, 8*float(s.get_amplitud_scale()), float(s.get_amplitud_scale())))
    pylab.savefig('%s' % sys.argv[2])
    #pylab.show()
    print "Captura %s terminada" % sys.argv[2]
    sys.exit(0)