ad4130_sensor_measurement.py

00001 import serial
00002 from time import sleep
00003 from pynput import keyboard
00004 from adi import ad4130
00005 from ad4130_xattr import *
00006 
00007 # Delays in seconds
00008 short_time = 0.1
00009 long_time = 1
00010 loadcell_settling_time = 2
00011 
00012 # Global variables
00013 weight_input = 0
00014 loadcell_offset = [ 0 ]
00015 loadcell_gain = [ 0 ]
00016 
00017 # Power test channels defined in the firmware
00018 POWER_TEST_V_AVDD_CHN = 0
00019 POWER_TEST_V_IOVDD_CHN = 1
00020 POWER_TEST_I_AVDD_CHN = 2
00021 POWER_TEST_I_IOVDD_CHN = 3
00022 POWER_TEST_V_AVSS_DGND_CHN = 4
00023 POWER_TEST_V_REF_CHN = 5
00024 
00025 # IIO Channel name and respective channel index mapping
00026 chn_mappping = {
00027     "voltage0" : 0, "voltage1" : 1, "voltage2" : 2, "voltage3" : 3, "voltage4" : 4,
00028     "voltage5" : 5, "voltage6" : 6, "voltage7" : 7, "voltage8" : 8, "voltage9" : 9,
00029     "voltage10" : 10, "voltage11" : 11, "voltage12" : 12, "voltage13" : 13,
00030     "voltage14" : 14, "voltage15" : 15,
00031 
00032     "current0" : 0, "current1" : 1, "current2" : 2, "current3" : 3, "current4" : 4,
00033     "current5" : 5, "current6" : 6, "current7" : 7, "current8" : 8, "current9" : 9,
00034     "current10" : 10, "current11" : 11, "current12" : 12, "current13" : 13,
00035     "current14" : 14, "current15" : 15,
00036 
00037     "temp0" : 0, "temp1" : 1, "temp2" : 2, "temp3" : 3, "temp4" : 4,
00038     "temp5" : 5, "temp6" : 6, "temp7" : 7, "temp8" : 8, "temp9" : 9,
00039     "temp10" : 10, "temp11" : 11, "temp12" : 12, "temp13" : 13,
00040     "temp14" : 14, "temp15" : 15,
00041 }
00042 
00043 def key_press_event(key):
00044     global key_pressed
00045     key_pressed = True
00046 
00047 def init_sensor_measurement():
00048     global device
00049     global demo_config
00050     global listener
00051 
00052     ######## User configuration ##########
00053     # Configure the backend for PC to IIOD interface
00054     uri = "serial:COM12,230400"  # For UART, baud rate must be same as set in the FW. COM port is physical Or VCOM.
00055     device_name = "ad4130-8"     # Name of the device must be same as set in the FW.
00056     ######################################
00057 
00058     # Create an IIO device context
00059     device = ad4130_xattr(uri, device_name)
00060     device._ctx.set_timeout(100000)
00061 
00062     # Get current user device config from the firmware
00063     demo_config = device.demo_config
00064     print("\r\nDemo Config: {}\r\n".format(demo_config))
00065 
00066     listener = keyboard.Listener(on_press=key_press_event)
00067     listener.start()
00068 
00069 def perform_loadcell_calibration(chn):
00070         global loadcell_offset
00071         global loadcell_gain
00072         global weight_input
00073         global device
00074 
00075         chn_indx = chn_mappping[chn.name]
00076 
00077         print("\r\nCalibrating Loadcell for channel {}".format(chn_indx))
00078         input("Please ensure no weight is applied on Loadcell and press enter to continue calibration ")
00079         print("Waiting to settle-down the Loadcell..")
00080         sleep(loadcell_settling_time)
00081         print("Performing Loadcell offset calibration..")
00082         chn.loadcell_offset_calibration = 'start_calibration'
00083         print("Loadcell offset calibration complete")
00084         loadcell_offset[chn_indx] = chn.loadcell_offset_calibration
00085         print("Loadcell offset: {}".format(loadcell_offset[chn_indx]))
00086 
00087         weight_input_done = False
00088         while weight_input_done is False:
00089             try:
00090                 weight_input = int(input("\r\nApply the weight on loadcell and enter here (in grams): "))
00091                 if (weight_input <= 0):
00092                     print("Please ensure weight is > 0!!")
00093                 else:
00094                     weight_input_done = True
00095             except:
00096                 print("Invalid input")
00097 
00098         print("Waiting to settle-down the Loadcell..")
00099         sleep(loadcell_settling_time)
00100         print("Performing load cell gain calibration..")
00101         chn.loadcell_gain_calibration = 'start_calibration'
00102         print("Load cell gain calibration complete")
00103         loadcell_gain[chn_indx] = chn.loadcell_gain_calibration
00104         print("Loadcell gain: {}".format(loadcell_gain[chn_indx]))
00105 
00106 def perform_sensor_measurement():
00107     global device
00108     global key_pressed
00109     global loadcell_offset
00110     global loadcell_gain
00111     global weight_input
00112 
00113     # Loadcell must be calibrated before performing measurement
00114     if (demo_config == 'Loadcell'):
00115         for chn in device.channel:
00116             perform_loadcell_calibration(chn)
00117 
00118     weight = 0
00119     print("\r\n*** Press any key to stop the measurement ***\r\n")
00120     sleep(long_time)
00121     
00122     # Print the header
00123     header = ""
00124     for chn in device.channel:
00125         header = header + chn.name + ' '
00126     print(header)
00127 
00128     key_pressed = False
00129     while not key_pressed:
00130         result_str = ""
00131         for chn in device.channel:
00132             sleep(short_time)
00133             if (demo_config == 'Loadcell'):
00134                 adc_raw = chn.raw
00135                 try:
00136                     chn_indx = chn_mappping[chn.name]
00137                     weight = ((adc_raw - loadcell_offset[chn_indx]) * weight_input) / (loadcell_gain[chn_indx] - loadcell_offset[chn_indx])
00138                     result_str = result_str + str(round(weight,4)) + ' gram  '
00139                 except:
00140                     print("\r\nInvalid measurement result. Please check device settings!!")
00141                     break
00142             elif (demo_config == 'ECG' or demo_config == 'Noise Test' or demo_config == 'Power Test' or demo_config == 'User Default'):
00143                 adc_raw = chn.raw
00144                 scale = chn.scale
00145                 offset = chn.offset
00146                 if (demo_config == 'Power Test'):
00147                     chn_indx = chn_mappping[chn.name]
00148                     if (chn_indx == POWER_TEST_I_AVDD_CHN or chn_indx == POWER_TEST_I_IOVDD_CHN):
00149                         current = ((adc_raw + offset) * scale)
00150                         result_str = result_str + str(round(current,4)) + 'mA  '
00151                     else:
00152                         voltage = ((adc_raw + offset) * scale) / 1000
00153                         result_str = result_str + str(round(voltage,4)) + 'V  '
00154                 else:
00155                     voltage = ((adc_raw + offset) * scale) / 1000
00156                     result_str = result_str + str(round(voltage,4)) + 'V  '
00157             else:
00158                 # Temperature sensors demo configs (RTD, Thermocouple and Thermistor)
00159                 adc_raw = chn.raw
00160                 scale = chn.scale
00161                 temperature = (adc_raw * scale) / 1000
00162                 result_str = result_str + str(round(temperature,4)) + 'C  '
00163 
00164         print(result_str)
00165 
00166 def exit():
00167     global listener
00168     global device
00169 
00170     # Delete the objects
00171     del listener
00172     del device
00173 
00174 def main():
00175     init_sensor_measurement()
00176     perform_sensor_measurement()
00177     exit()
00178 
00179 if __name__ == "__main__":
00180     main()