forked from fossasia/pslab-python
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathAD7718_class.py
More file actions
255 lines (215 loc) · 7.37 KB
/
AD7718_class.py
File metadata and controls
255 lines (215 loc) · 7.37 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
from __future__ import print_function
import time
import numpy as np
'''
The running directory must have caldata.py containing dictionary called 'calibs' in it.
The entries of the dictionary will be of the form
calibs={
'AIN6AINCOM':[6.993123e-07,-1.563294e-06,9.994211e-01,-4.596018e-03],
...
}
'''
def _bv(x):
return 1 << x
class AD7718:
VREF = 3.3
STATUS = 0
MODE = 1
ADCCON = 2
FILTER = 3
ADCDATA = 4
ADCOFFSET = 5
ADCGAIN = 6
IOCON = 7
TEST1 = 12
TEST2 = 13
ID = 15
# bit definitions
MODE_PD = 0
MODE_IDLE = 1
MODE_SINGLE = 2
MODE_CONT = 3
MODE_INT_ZEROCAL = 4
MODE_INT_FULLCAL = 5
MODE_SYST_ZEROCAL = 6
MODE_SYST_FULLCAL = 7
MODE_OSCPD = _bv(3)
MODE_CHCON = _bv(4)
MODE_REFSEL = _bv(5)
MODE_NEGBUF = _bv(6)
MODE_NOCHOP = _bv(7)
CON_AIN1AINCOM = 0 << 4
CON_AIN2AINCOM = 1 << 4
CON_AIN3AINCOM = 2 << 4
CON_AIN4AINCOM = 3 << 4
CON_AIN5AINCOM = 4 << 4
CON_AIN6AINCOM = 5 << 4
CON_AIN7AINCOM = 6 << 4
CON_AIN8AINCOM = 7 << 4
CON_AIN1AIN2 = 8 << 4
CON_AIN3AIN4 = 9 << 4
CON_AIN5AIN6 = 10 << 4
CON_AIN7AIN8 = 11 << 4
CON_AIN2AIN2 = 12 << 4
CON_AINCOMAINCOM = 13 << 4
CON_REFINREFIN = 14 << 4
CON_OPEN = 15 << 4
CON_UNIPOLAR = _bv(3)
CON_RANGE0 = 0 # +-20mV
CON_RANGE1 = 1 # +-40mV
CON_RANGE2 = 2 # +-80mV
CON_RANGE3 = 3 # +-160mV
CON_RANGE4 = 4 # +-320mV
CON_RANGE5 = 5 # +-640mV
CON_RANGE6 = 6 # +-1280mV
CON_RANGE7 = 7 # +-2560mV
gain = 1
CHAN_NAMES = ['AIN1AINCOM', 'AIN2AINCOM', 'AIN3AINCOM', 'AIN4AINCOM', 'AIN5AINCOM',
'AIN6AINCOM', 'AIN7AINCOM', 'AIN8AINCOM']
def __init__(self, I, calibs):
self.cs = 'CS1'
self.I = I
self.calibs = calibs
self.I.SPI.set_parameters(2, 1, 0, 1)
self.writeRegister(self.FILTER, 20)
self.writeRegister(self.MODE, self.MODE_SINGLE | self.MODE_CHCON | self.MODE_REFSEL)
self.caldata = {}
for a in calibs.keys():
self.caldata[a] = np.poly1d(calibs[a])
print('Loaded calibration', self.caldata)
def start(self):
self.I.SPI.start(self.cs)
def stop(self):
self.I.SPI.stop(self.cs)
def send8(self, val):
return self.I.SPI.send8(val)
def send16(self, val):
return self.I.SPI.send16(val)
def write(self, regname, value):
pass
def readRegister(self, regname):
self.start()
val = self.send16(0x4000 | (regname << 8))
self.stop()
# print (regname,val)
val &= 0x00FF
return val
def readData(self):
self.start()
val = self.send16(0x4000 | (self.ADCDATA << 8))
val &= 0xFF
val <<= 16
val |= self.send16(0x0000)
self.stop()
return val
def writeRegister(self, regname, value):
self.start()
val = self.send16(0x0000 | (regname << 8) | value)
self.stop()
return val
def internalCalibration(self, chan=1):
self.start()
val = self.send16(0x0000 | (self.ADCCON << 8) | (chan << 4) | 7) # range=7
start_time = time.time()
caldone = False
val = self.send16(0x0000 | (self.MODE << 8) | 4)
while caldone != 1:
time.sleep(0.5)
caldone = self.send16(0x4000 | (self.MODE << 8)) & 7
print('waiting for zero scale calibration... %.2f S, %d' % (time.time() - start_time, caldone))
print('\n')
caldone = False
val = self.send16(0x0000 | (self.MODE << 8) | 5)
while caldone != 1:
time.sleep(0.5)
caldone = self.send16(0x4000 | (self.MODE << 8)) & 7
print('waiting for full scale calibration... %.2f S %d' % (time.time() - start_time, caldone))
print('\n')
self.stop()
def readCalibration(self):
self.start()
off = self.send16(0x4000 | (self.ADCOFFSET << 8))
off &= 0xFF
off <<= 16
off |= self.send16(0x0000)
gn = self.send16(0x4000 | (self.ADCGAIN << 8))
gn &= 0xFF
gn <<= 16
gn |= self.send16(0x0000)
self.stop()
return off, gn
def configADC(self, adccon):
self.writeRegister(self.ADCCON, adccon) # unipolar channels , range
self.gain = 2 ** (7 - adccon & 3)
def printstat(self):
stat = self.readRegister(self.STATUS)
P = ['PLL LOCKED', 'RES', 'RES', 'ADC ERROR', 'RES', 'CAL DONE', 'RES', 'READY']
N = ['PLL ERROR', 'RES', 'RES', 'ADC OKAY', 'RES', 'CAL LOW', 'RES', 'NOT READY']
s = ''
for a in range(8):
if stat & (1 << a):
s += '\t' + P[a]
else:
s += '\t' + N[a]
print(stat, s)
def convert_unipolar(self, x):
return (1.024 * self.VREF * x) / (self.gain * 2 ** 24)
def convert_bipolar(self, x):
return ((x / 2 ** 24) - 1) * (1.024 * self.VREF) / (self.gain)
def __startRead__(self, chan):
if chan not in self.CHAN_NAMES:
print('invalid channel name. try AIN1AINCOM')
return False
chanid = self.CHAN_NAMES.index(chan)
self.configADC(self.CON_RANGE7 | self.CON_UNIPOLAR | (chanid << 4))
self.writeRegister(self.MODE, self.MODE_SINGLE | self.MODE_CHCON | self.MODE_REFSEL)
return True
def __fetchData__(self, chan):
while True:
stat = self.readRegister(self.STATUS)
if stat & 0x80:
data = float(self.readData())
data = self.convert_unipolar(data)
if int(chan[3]) > 4: data = (data - 3.3 / 2) * 4
return self.caldata[chan](data)
else:
time.sleep(0.1)
print('increase delay')
return False
def readVoltage(self, chan):
if not self.__startRead__(chan):
return False
time.sleep(0.15)
return self.__fetchData__(chan)
def __fetchRawData__(self, chan):
while True:
stat = self.readRegister(self.STATUS)
if stat & 0x80:
data = float(self.readData())
return self.convert_unipolar(data)
else:
time.sleep(0.01)
print('increase delay')
return False
def readRawVoltage(self, chan):
if not self.__startRead__(chan):
return False
time.sleep(0.15)
return self.__fetchRawData__(chan)
if __name__ == "__main__":
from PSL import sciencelab
I = sciencelab.connect()
calibs = {
'AIN6AINCOM': [6.993123e-07, -1.563294e-06, 9.994211e-01, -4.596018e-03],
'AIN7AINCOM': [3.911521e-07, -1.706405e-06, 1.002294e+00, -1.286302e-02],
'AIN3AINCOM': [-3.455831e-06, 2.861689e-05, 1.000195e+00, 3.802349e-04],
'AIN1AINCOM': [8.220199e-05, -4.587100e-04, 1.001015e+00, -1.684517e-04],
'AIN5AINCOM': [-1.250787e-07, -9.203838e-07, 1.000299e+00, -1.262684e-03],
'AIN2AINCOM': [5.459186e-06, -1.749624e-05, 1.000268e+00, 1.907896e-04],
'AIN9AINCOM': [7.652808e+00, 1.479229e+00, 2.832601e-01, 4.495232e-02],
'AIN8AINCOM': [8.290843e-07, -7.129532e-07, 9.993159e-01, 3.307947e-03],
'AIN4AINCOM': [4.135213e-06, -1.973478e-05, 1.000277e+00, 2.115374e-04], }
A = AD7718(I, calibs)
for a in range(10):
print(A.readRawVoltage('AIN1AINCOM'))
time.sleep(0.3)