jupyterpidaq.Boards.PiGPIO.DAQC2
1# Utility sampling routines for using the ADC block of the 2# Pi-Plates DAQC2plate RPI HAT. 3# J. Gutow <gutow@uwosh.edu> June 2020 4# license GPL V3 or greater 5import time 6import numpy as np 7 8import logging 9 10try: 11 from piplates import DAQC2plate 12except Exception as e: 13 print("\nDAQC2plate: "+str(e), end='') 14 DAQC2plate = None 15 16from jupyterpidaq.Boards import Board 17 18logger = logging.getLogger(__name__) 19 20# Optimized for Pi 3B+ for an installed ADS1115 ADC PiHAT. This is 21# actually ignored by this board, but necessary for ADC call 22# compatibility. 23RATE = 475 24 25def find_boards(): 26 """ 27 A rountine like this must be implemented by all board packages. 28 29 :return: list of DAQC2 board objects (maximum of 8 boards) 30 """ 31 boards = [] 32 tmpmod = None 33 if DAQC2plate: 34 for addr in range(len(DAQC2plate.daqc2sPresent)): 35 if DAQC2plate.daqc2sPresent[addr] == 1: 36 boards.append(Board_DAQC2(addr)) 37 return boards 38 39 40class Board_DAQC2(Board): 41 """ 42 Class defining the properties of the analog-to-digital block of the 43 pi-Plates DAQC2 board. Key characteristics: 44 45 * 8 channels (0 - 7) with pseudo 16 bit resolution (oversampled 14 bit) and 46 a range of +/- 12 V. 47 * 1 channel (8) dedicated to monitoring Vdd. 48 * Programmable RGB LED to use as indicator. 49 * Other available facilities are Digital I/O, Digital-to-Analog and 50 2-channel o-scope modes. These are not supported by this class. 51 """ 52 def __init__(self, addr): 53 super().__init__() 54 self.name = 'DAQC2' 55 self.vendor = 'Pi-Plates' 56 # Note: channel 8 is wired to Vdd so cannot be used for measurements. 57 self.channels = (0, 1, 2, 3, 4, 5, 6, 7, 8) 58 self.addr = addr 59 # Flash light green and then off to indicated found and set up. 60 DAQC2plate.setLED(self.addr,'green') 61 Vddcheck = float(self.V_oversampchan(8,1,5)[0]) 62 self.Vdd = Vddcheck 63 DAQC2plate.setLED(self.addr,'off') 64 65 def getsensors(self): 66 """ 67 Return a list of valid sensor object names for this board. 68 :return: list of classnames 69 """ 70 sensorlist = ['RawAtoD', 71 'VernierSSTemp', 72 'VernierGasP', 73 'VernierGasP_OLD', 74 'VernierpH', 75 'VernierFlatpH' 76 ] 77 # TODO: extend this list as appropriate. You can get a full list 78 # using the `Sensors.sensors.listSensors()` call. 79 # The main program will use this list to access the actual sensor 80 # objects when converting the raw board voltage and for producing 81 # a menu of valid options for this particular board. 82 return sensorlist 83 84 def V_oversampchan(self, chan, gain, avg_sec, data_rate=RATE): 85 """ 86 This routine returns the average voltage for the channel 87 averaged at the default rate for the board and returns an 88 average and observed range. 89 90 Returns a tuple of the following 5 objects: 91 V_avg -- float, the averaged voltage 92 93 V_min -- float, the minimum voltage read during 94 the interval 95 96 V_max -- float, the maximum voltage read during the 97 interval 98 99 time_stamp -- float, the time at halfway through the averaging 100 interval in seconds since the beginning of the epoch (OS 101 dependent begin time) 102 103 Vdd_avg -- float, the reference voltage (Vdd) collected 104 simultaneously. 105 106 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 107 8). NOTE: channel 8 returns a measurement of Vdd. 108 109 :param gain: ignored by board. Defaults to 1. 110 111 :param int data_rate: ignored by board. 112 113 :param float avg_sec: seconds to average for, actual 114 averaging interval will be as close as possible for an integer 115 number of samples 116 117 :returns: V_avg, V_min, V_max, time_stamp, Vdd_avg 118 :return float V_avg: description 119 :return float V_min: 120 :return float V_max: 121 :return float time_stamp: 122 :return float Vdd_avg: 123 """ 124 value = [] 125 ref = [] 126 starttime = time.time() 127 endtime = starttime + avg_sec 128 while time.time() < endtime: 129 value.append(DAQC2plate.getADC(self.addr, chan)) 130 ref.append(DAQC2plate.getADC(self.addr, 8)) 131 time_stamp = (endtime + endtime) / 2 132 ndata = len(value) 133 V_avg = sum(value) / ndata 134 Vdd_avg = sum(ref) / ndata 135 V_min = min(value) 136 V_max = max(value) 137 return V_avg, V_min, V_max, time_stamp, Vdd_avg 138 139 def V_oversampchan_stats(self, chan, gain, avg_sec, data_rate=RATE): 140 ''' 141 This routine returns the average voltage for the channel 142 averaged at the maximum rate for the board. The standard 143 deviation and the estimated deviation of the mean are also 144 returned. 145 146 Returns a tuple of the following 5 objects: 147 V_avg -- float, the averaged voltage 148 149 stdev -- float, the standard deviation of the measured values 150 during the averaging interval 151 152 stdev_avg -- float, the estimated standard deviation of the 153 returned average 154 155 time_stamp -- float, the time at halfway through the averaging 156 interval in seconds since the beginning of the epoch (OS 157 dependent begin time) 158 159 Vdd_avg -- float, the reference voltage (Vdd) collected 160 simultaneously. 161 162 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 163 8). NOTE: channel 8 returns a measurement of Vdd. 164 165 :param gain: ignored by board. Defaults to 1. 166 167 :param int data_rate: ignored by board. 168 169 :param float avg_sec: seconds to average for, actual 170 averaging interval will be as close as possible for an integer 171 number of samples 172 173 :returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 174 :return float V_avg: description 175 :return float stdev: 176 :return float stdev_avg: 177 :return float time_stamp: 178 :return float Vdd_avg: 179 ''' 180 value = [] 181 ref = [] 182 starttime = time.time() 183 endtime = starttime + avg_sec 184 while time.time() < endtime: 185 value.append(DAQC2plate.getADC(self.addr, chan)) 186 ref.append(DAQC2plate.getADC(self.addr, 8)) 187 time_stamp = (starttime + endtime) / 2 188 ndata = len(value) 189 logging.debug('channel:'+str(chan)+', starttime:'+str(starttime)+', ' 190 'endtime:'+str(endtime)+', ndata:'+str(ndata)+'.') 191 V_avg = sum(value) / ndata 192 Vdd_avg = sum(ref) / ndata 193 stdev = np.std(value, ddof=1, dtype=np.float64) 194 stdev_avg = stdev / np.sqrt(float(ndata)) 195 return V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 196 197 def V_sampchan(self, chan, gain, data_rate=RATE): 198 ''' 199 This routine returns a single reading of the voltage for the channel. 200 201 Returns a tuple of the following 5 objects: 202 V -- float, the measured voltage 203 204 time_stamp -- float, the time of the measurement in seconds since 205 the beginning of the epoch (OS dependent begin time) 206 207 ref -- float, the reference voltage (Vdd) collected 208 simultaneously. 209 210 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 211 8). NOTE: channel 8 returns a measurement of Vdd. 212 213 :param gain: ignored by board. Defaults to 1. 214 215 :param int data_rate: ignored by board. 216 217 :returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 218 :return float V: 219 :return float time_stamp: 220 :return float ref: 221 ''' 222 start = time.time() 223 value = DAQC2plate.getADC(self.addr, chan) 224 ref = DAQC2plate.getADC(self.addr, 8) 225 end = time.time() 226 time_stamp = (start + end) / 2 227 return value, time_stamp, ref
def
find_boards():
26def find_boards(): 27 """ 28 A rountine like this must be implemented by all board packages. 29 30 :return: list of DAQC2 board objects (maximum of 8 boards) 31 """ 32 boards = [] 33 tmpmod = None 34 if DAQC2plate: 35 for addr in range(len(DAQC2plate.daqc2sPresent)): 36 if DAQC2plate.daqc2sPresent[addr] == 1: 37 boards.append(Board_DAQC2(addr)) 38 return boards
A rountine like this must be implemented by all board packages.
Returns
list of DAQC2 board objects (maximum of 8 boards)
41class Board_DAQC2(Board): 42 """ 43 Class defining the properties of the analog-to-digital block of the 44 pi-Plates DAQC2 board. Key characteristics: 45 46 * 8 channels (0 - 7) with pseudo 16 bit resolution (oversampled 14 bit) and 47 a range of +/- 12 V. 48 * 1 channel (8) dedicated to monitoring Vdd. 49 * Programmable RGB LED to use as indicator. 50 * Other available facilities are Digital I/O, Digital-to-Analog and 51 2-channel o-scope modes. These are not supported by this class. 52 """ 53 def __init__(self, addr): 54 super().__init__() 55 self.name = 'DAQC2' 56 self.vendor = 'Pi-Plates' 57 # Note: channel 8 is wired to Vdd so cannot be used for measurements. 58 self.channels = (0, 1, 2, 3, 4, 5, 6, 7, 8) 59 self.addr = addr 60 # Flash light green and then off to indicated found and set up. 61 DAQC2plate.setLED(self.addr,'green') 62 Vddcheck = float(self.V_oversampchan(8,1,5)[0]) 63 self.Vdd = Vddcheck 64 DAQC2plate.setLED(self.addr,'off') 65 66 def getsensors(self): 67 """ 68 Return a list of valid sensor object names for this board. 69 :return: list of classnames 70 """ 71 sensorlist = ['RawAtoD', 72 'VernierSSTemp', 73 'VernierGasP', 74 'VernierGasP_OLD', 75 'VernierpH', 76 'VernierFlatpH' 77 ] 78 # TODO: extend this list as appropriate. You can get a full list 79 # using the `Sensors.sensors.listSensors()` call. 80 # The main program will use this list to access the actual sensor 81 # objects when converting the raw board voltage and for producing 82 # a menu of valid options for this particular board. 83 return sensorlist 84 85 def V_oversampchan(self, chan, gain, avg_sec, data_rate=RATE): 86 """ 87 This routine returns the average voltage for the channel 88 averaged at the default rate for the board and returns an 89 average and observed range. 90 91 Returns a tuple of the following 5 objects: 92 V_avg -- float, the averaged voltage 93 94 V_min -- float, the minimum voltage read during 95 the interval 96 97 V_max -- float, the maximum voltage read during the 98 interval 99 100 time_stamp -- float, the time at halfway through the averaging 101 interval in seconds since the beginning of the epoch (OS 102 dependent begin time) 103 104 Vdd_avg -- float, the reference voltage (Vdd) collected 105 simultaneously. 106 107 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 108 8). NOTE: channel 8 returns a measurement of Vdd. 109 110 :param gain: ignored by board. Defaults to 1. 111 112 :param int data_rate: ignored by board. 113 114 :param float avg_sec: seconds to average for, actual 115 averaging interval will be as close as possible for an integer 116 number of samples 117 118 :returns: V_avg, V_min, V_max, time_stamp, Vdd_avg 119 :return float V_avg: description 120 :return float V_min: 121 :return float V_max: 122 :return float time_stamp: 123 :return float Vdd_avg: 124 """ 125 value = [] 126 ref = [] 127 starttime = time.time() 128 endtime = starttime + avg_sec 129 while time.time() < endtime: 130 value.append(DAQC2plate.getADC(self.addr, chan)) 131 ref.append(DAQC2plate.getADC(self.addr, 8)) 132 time_stamp = (endtime + endtime) / 2 133 ndata = len(value) 134 V_avg = sum(value) / ndata 135 Vdd_avg = sum(ref) / ndata 136 V_min = min(value) 137 V_max = max(value) 138 return V_avg, V_min, V_max, time_stamp, Vdd_avg 139 140 def V_oversampchan_stats(self, chan, gain, avg_sec, data_rate=RATE): 141 ''' 142 This routine returns the average voltage for the channel 143 averaged at the maximum rate for the board. The standard 144 deviation and the estimated deviation of the mean are also 145 returned. 146 147 Returns a tuple of the following 5 objects: 148 V_avg -- float, the averaged voltage 149 150 stdev -- float, the standard deviation of the measured values 151 during the averaging interval 152 153 stdev_avg -- float, the estimated standard deviation of the 154 returned average 155 156 time_stamp -- float, the time at halfway through the averaging 157 interval in seconds since the beginning of the epoch (OS 158 dependent begin time) 159 160 Vdd_avg -- float, the reference voltage (Vdd) collected 161 simultaneously. 162 163 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 164 8). NOTE: channel 8 returns a measurement of Vdd. 165 166 :param gain: ignored by board. Defaults to 1. 167 168 :param int data_rate: ignored by board. 169 170 :param float avg_sec: seconds to average for, actual 171 averaging interval will be as close as possible for an integer 172 number of samples 173 174 :returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 175 :return float V_avg: description 176 :return float stdev: 177 :return float stdev_avg: 178 :return float time_stamp: 179 :return float Vdd_avg: 180 ''' 181 value = [] 182 ref = [] 183 starttime = time.time() 184 endtime = starttime + avg_sec 185 while time.time() < endtime: 186 value.append(DAQC2plate.getADC(self.addr, chan)) 187 ref.append(DAQC2plate.getADC(self.addr, 8)) 188 time_stamp = (starttime + endtime) / 2 189 ndata = len(value) 190 logging.debug('channel:'+str(chan)+', starttime:'+str(starttime)+', ' 191 'endtime:'+str(endtime)+', ndata:'+str(ndata)+'.') 192 V_avg = sum(value) / ndata 193 Vdd_avg = sum(ref) / ndata 194 stdev = np.std(value, ddof=1, dtype=np.float64) 195 stdev_avg = stdev / np.sqrt(float(ndata)) 196 return V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 197 198 def V_sampchan(self, chan, gain, data_rate=RATE): 199 ''' 200 This routine returns a single reading of the voltage for the channel. 201 202 Returns a tuple of the following 5 objects: 203 V -- float, the measured voltage 204 205 time_stamp -- float, the time of the measurement in seconds since 206 the beginning of the epoch (OS dependent begin time) 207 208 ref -- float, the reference voltage (Vdd) collected 209 simultaneously. 210 211 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 212 8). NOTE: channel 8 returns a measurement of Vdd. 213 214 :param gain: ignored by board. Defaults to 1. 215 216 :param int data_rate: ignored by board. 217 218 :returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 219 :return float V: 220 :return float time_stamp: 221 :return float ref: 222 ''' 223 start = time.time() 224 value = DAQC2plate.getADC(self.addr, chan) 225 ref = DAQC2plate.getADC(self.addr, 8) 226 end = time.time() 227 time_stamp = (start + end) / 2 228 return value, time_stamp, ref
Class defining the properties of the analog-to-digital block of the pi-Plates DAQC2 board. Key characteristics:
- 8 channels (0 - 7) with pseudo 16 bit resolution (oversampled 14 bit) and a range of +/- 12 V.
- 1 channel (8) dedicated to monitoring Vdd.
- Programmable RGB LED to use as indicator.
- Other available facilities are Digital I/O, Digital-to-Analog and 2-channel o-scope modes. These are not supported by this class.
Board_DAQC2(addr)
53 def __init__(self, addr): 54 super().__init__() 55 self.name = 'DAQC2' 56 self.vendor = 'Pi-Plates' 57 # Note: channel 8 is wired to Vdd so cannot be used for measurements. 58 self.channels = (0, 1, 2, 3, 4, 5, 6, 7, 8) 59 self.addr = addr 60 # Flash light green and then off to indicated found and set up. 61 DAQC2plate.setLED(self.addr,'green') 62 Vddcheck = float(self.V_oversampchan(8,1,5)[0]) 63 self.Vdd = Vddcheck 64 DAQC2plate.setLED(self.addr,'off')
Should be overridden by each board and define at minimum: self.name = 'board name/adc name/type' Short an useful to end user self.vendor = 'Vendor/Manufacturer name` self.channels = tuple of available channel IDs self.gains = list of gains self.Vdd = voltage provided by board to sensors
def
getsensors(self):
66 def getsensors(self): 67 """ 68 Return a list of valid sensor object names for this board. 69 :return: list of classnames 70 """ 71 sensorlist = ['RawAtoD', 72 'VernierSSTemp', 73 'VernierGasP', 74 'VernierGasP_OLD', 75 'VernierpH', 76 'VernierFlatpH' 77 ] 78 # TODO: extend this list as appropriate. You can get a full list 79 # using the `Sensors.sensors.listSensors()` call. 80 # The main program will use this list to access the actual sensor 81 # objects when converting the raw board voltage and for producing 82 # a menu of valid options for this particular board. 83 return sensorlist
Return a list of valid sensor object names for this board.
Returns
list of classnames
def
V_oversampchan(self, chan, gain, avg_sec, data_rate=475):
85 def V_oversampchan(self, chan, gain, avg_sec, data_rate=RATE): 86 """ 87 This routine returns the average voltage for the channel 88 averaged at the default rate for the board and returns an 89 average and observed range. 90 91 Returns a tuple of the following 5 objects: 92 V_avg -- float, the averaged voltage 93 94 V_min -- float, the minimum voltage read during 95 the interval 96 97 V_max -- float, the maximum voltage read during the 98 interval 99 100 time_stamp -- float, the time at halfway through the averaging 101 interval in seconds since the beginning of the epoch (OS 102 dependent begin time) 103 104 Vdd_avg -- float, the reference voltage (Vdd) collected 105 simultaneously. 106 107 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 108 8). NOTE: channel 8 returns a measurement of Vdd. 109 110 :param gain: ignored by board. Defaults to 1. 111 112 :param int data_rate: ignored by board. 113 114 :param float avg_sec: seconds to average for, actual 115 averaging interval will be as close as possible for an integer 116 number of samples 117 118 :returns: V_avg, V_min, V_max, time_stamp, Vdd_avg 119 :return float V_avg: description 120 :return float V_min: 121 :return float V_max: 122 :return float time_stamp: 123 :return float Vdd_avg: 124 """ 125 value = [] 126 ref = [] 127 starttime = time.time() 128 endtime = starttime + avg_sec 129 while time.time() < endtime: 130 value.append(DAQC2plate.getADC(self.addr, chan)) 131 ref.append(DAQC2plate.getADC(self.addr, 8)) 132 time_stamp = (endtime + endtime) / 2 133 ndata = len(value) 134 V_avg = sum(value) / ndata 135 Vdd_avg = sum(ref) / ndata 136 V_min = min(value) 137 V_max = max(value) 138 return V_avg, V_min, V_max, time_stamp, Vdd_avg
This routine returns the average voltage for the channel averaged at the default rate for the board and returns an average and observed range.
Returns a tuple of the following 5 objects: V_avg -- float, the averaged voltage
V_min -- float, the minimum voltage read during
the interval
V_max -- float, the maximum voltage read during the
interval
time_stamp -- float, the time at halfway through the averaging
interval in seconds since the beginning of the epoch (OS
dependent begin time)
Vdd_avg -- float, the reference voltage (Vdd) collected
simultaneously.
Parameters
int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 8). NOTE: channel 8 returns a measurement of Vdd.
gain: ignored by board. Defaults to 1.
int data_rate: ignored by board.
float avg_sec: seconds to average for, actual averaging interval will be as close as possible for an integer number of samples
:returns: V_avg, V_min, V_max, time_stamp, Vdd_avg
Returns
description
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def
V_oversampchan_stats(self, chan, gain, avg_sec, data_rate=475):
140 def V_oversampchan_stats(self, chan, gain, avg_sec, data_rate=RATE): 141 ''' 142 This routine returns the average voltage for the channel 143 averaged at the maximum rate for the board. The standard 144 deviation and the estimated deviation of the mean are also 145 returned. 146 147 Returns a tuple of the following 5 objects: 148 V_avg -- float, the averaged voltage 149 150 stdev -- float, the standard deviation of the measured values 151 during the averaging interval 152 153 stdev_avg -- float, the estimated standard deviation of the 154 returned average 155 156 time_stamp -- float, the time at halfway through the averaging 157 interval in seconds since the beginning of the epoch (OS 158 dependent begin time) 159 160 Vdd_avg -- float, the reference voltage (Vdd) collected 161 simultaneously. 162 163 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 164 8). NOTE: channel 8 returns a measurement of Vdd. 165 166 :param gain: ignored by board. Defaults to 1. 167 168 :param int data_rate: ignored by board. 169 170 :param float avg_sec: seconds to average for, actual 171 averaging interval will be as close as possible for an integer 172 number of samples 173 174 :returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 175 :return float V_avg: description 176 :return float stdev: 177 :return float stdev_avg: 178 :return float time_stamp: 179 :return float Vdd_avg: 180 ''' 181 value = [] 182 ref = [] 183 starttime = time.time() 184 endtime = starttime + avg_sec 185 while time.time() < endtime: 186 value.append(DAQC2plate.getADC(self.addr, chan)) 187 ref.append(DAQC2plate.getADC(self.addr, 8)) 188 time_stamp = (starttime + endtime) / 2 189 ndata = len(value) 190 logging.debug('channel:'+str(chan)+', starttime:'+str(starttime)+', ' 191 'endtime:'+str(endtime)+', ndata:'+str(ndata)+'.') 192 V_avg = sum(value) / ndata 193 Vdd_avg = sum(ref) / ndata 194 stdev = np.std(value, ddof=1, dtype=np.float64) 195 stdev_avg = stdev / np.sqrt(float(ndata)) 196 return V_avg, stdev, stdev_avg, time_stamp, Vdd_avg
This routine returns the average voltage for the channel averaged at the maximum rate for the board. The standard deviation and the estimated deviation of the mean are also returned.
Returns a tuple of the following 5 objects: V_avg -- float, the averaged voltage
stdev -- float, the standard deviation of the measured values
during the averaging interval
stdev_avg -- float, the estimated standard deviation of the
returned average
time_stamp -- float, the time at halfway through the averaging
interval in seconds since the beginning of the epoch (OS
dependent begin time)
Vdd_avg -- float, the reference voltage (Vdd) collected
simultaneously.
Parameters
int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 8). NOTE: channel 8 returns a measurement of Vdd.
gain: ignored by board. Defaults to 1.
int data_rate: ignored by board.
float avg_sec: seconds to average for, actual averaging interval will be as close as possible for an integer number of samples
:returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg
Returns
description
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def
V_sampchan(self, chan, gain, data_rate=475):
198 def V_sampchan(self, chan, gain, data_rate=RATE): 199 ''' 200 This routine returns a single reading of the voltage for the channel. 201 202 Returns a tuple of the following 5 objects: 203 V -- float, the measured voltage 204 205 time_stamp -- float, the time of the measurement in seconds since 206 the beginning of the epoch (OS dependent begin time) 207 208 ref -- float, the reference voltage (Vdd) collected 209 simultaneously. 210 211 :param int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 212 8). NOTE: channel 8 returns a measurement of Vdd. 213 214 :param gain: ignored by board. Defaults to 1. 215 216 :param int data_rate: ignored by board. 217 218 :returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg 219 :return float V: 220 :return float time_stamp: 221 :return float ref: 222 ''' 223 start = time.time() 224 value = DAQC2plate.getADC(self.addr, chan) 225 ref = DAQC2plate.getADC(self.addr, 8) 226 end = time.time() 227 time_stamp = (start + end) / 2 228 return value, time_stamp, ref
This routine returns a single reading of the voltage for the channel.
Returns a tuple of the following 5 objects: V -- float, the measured voltage
time_stamp -- float, the time of the measurement in seconds since
the beginning of the epoch (OS dependent begin time)
ref -- float, the reference voltage (Vdd) collected
simultaneously.
Parameters
int chan: the channel number (0, 1, 2, 3, 4, 5, 6, 7, 8). NOTE: channel 8 returns a measurement of Vdd.
gain: ignored by board. Defaults to 1.
int data_rate: ignored by board.
:returns: V_avg, stdev, stdev_avg, time_stamp, Vdd_avg