# codigo básico de comunicacion con la placa de adquisición NI-daq621x
# de Diego Shalom
# https://github.com/diegoshalom/labosdf/blob/master/software/python/Labo5%202021/daq.py

# NI-DAQmx Python Documentation: https://nidaqmx-python.readthedocs.io/en/latest/index.html
# NI USB-621x User Manual: https://www.ni.com/pdf/manuals/371931f.pdf
import matplotlib.pyplot as plt
import numpy as np
import nidaqmx
import math
import time
import pandas as pd


#para saber el ID de la placa conectada (DevX)
system = nidaqmx.system.System.local()
for device in system.devices:
    print(device)

#para setear (y preguntar) el modo y rango de un canal analógico
with nidaqmx.Task() as task:
    ai_channel = task.ai_channels.add_ai_voltage_chan("Dev8/ai1",max_val=10,min_val=-10)
    print(ai_channel.ai_term_cfg)    
    print(ai_channel.ai_max)
    print(ai_channel.ai_min)	
	

## Medicion por tiempo/samples de una sola vez
def medir(duracion, fs):
    cant_puntos = duracion*fs    
    with nidaqmx.Task() as task:
        modo= nidaqmx.constants.TerminalConfiguration.DIFFERENTIAL
        task.ai_channels.add_ai_voltage_chan("Dev8/ai1", terminal_config = modo)
               
        task.timing.cfg_samp_clk_timing(fs,samps_per_chan = cant_puntos,
                                        sample_mode = nidaqmx.constants.AcquisitionType.FINITE)
        
        datos = task.read(number_of_samples_per_channel=nidaqmx.constants.READ_ALL_AVAILABLE)           
    datos = np.asarray(datos)    
    return datos

duracion = 1 #segundos
fs = 250000 #Frecuencia de muestreo

y = medir(duracion, fs)
plt.plot(y,'o')
plt.grid()
plt.show()

"""
## Medicion continua
fs = 250000 #Frecuencia de muestreo
task = nidaqmx.Task()
modo= nidaqmx.constants.TerminalConfiguration.DIFFERENTIAL
task.ai_channels.add_ai_voltage_chan("Dev8/ai1", terminal_config = modo)
task.timing.cfg_samp_clk_timing(fs, sample_mode = nidaqmx.constants.AcquisitionType.CONTINUOUS)
task.start()
t0 = time.time()
total = 0
for i in range(10):
    time.sleep(0.1)
    datos = task.read(number_of_samples_per_channel=nidaqmx.constants.READ_ALL_AVAILABLE)           
    total = total + len(datos)
    t1 = time.time()
    print("%2.3fs %d %d %2.3f" % (t1-t0, len(datos), total, total/(t1-t0)))    
"""
task.stop()
task.close()

df=pd.DataFrame(y)

df.to_csv('Mediciones'+str(time.localtime()[0])+'-'+str(time.localtime()[1])+'-'+str(time.localtime()[2])+'-'+str(time.localtime()[3])+'-'+str(time.localtime()[4])+'-'+str(time.localtime()[5])+'.csv')