-
Notifications
You must be signed in to change notification settings - Fork 1
/
ads1x15.py
252 lines (209 loc) · 9.68 KB
/
ads1x15.py
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
# The MIT License (MIT)
#
# Copyright (c) 2016 Radomir Dopieralski (@deshipu),
# 2017 Robert Hammelrath (@robert-hh)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
import utime as time
_REGISTER_MASK = const(0x03)
_REGISTER_CONVERT = const(0x00)
_REGISTER_CONFIG = const(0x01)
_REGISTER_LOWTHRESH = const(0x02)
_REGISTER_HITHRESH = const(0x03)
_OS_MASK = const(0x8000)
_OS_SINGLE = const(0x8000) # Write: Set to start a single-conversion
_OS_BUSY = const(0x0000) # Read: Bit=0 when conversion is in progress
_OS_NOTBUSY = const(0x8000) # Read: Bit=1 when no conversion is in progress
_MUX_MASK = const(0x7000)
_MUX_DIFF_0_1 = const(0x0000) # Differential P = AIN0, N = AIN1 (default)
_MUX_DIFF_0_3 = const(0x1000) # Differential P = AIN0, N = AIN3
_MUX_DIFF_1_3 = const(0x2000) # Differential P = AIN1, N = AIN3
_MUX_DIFF_2_3 = const(0x3000) # Differential P = AIN2, N = AIN3
_MUX_SINGLE_0 = const(0x4000) # Single-ended AIN0
_MUX_SINGLE_1 = const(0x5000) # Single-ended AIN1
_MUX_SINGLE_2 = const(0x6000) # Single-ended AIN2
_MUX_SINGLE_3 = const(0x7000) # Single-ended AIN3
_PGA_MASK = const(0x0E00)
_PGA_6_144V = const(0x0000) # +/-6.144V range = Gain 2/3
_PGA_4_096V = const(0x0200) # +/-4.096V range = Gain 1
_PGA_2_048V = const(0x0400) # +/-2.048V range = Gain 2 (default)
_PGA_1_024V = const(0x0600) # +/-1.024V range = Gain 4
_PGA_0_512V = const(0x0800) # +/-0.512V range = Gain 8
_PGA_0_256V = const(0x0A00) # +/-0.256V range = Gain 16
_MODE_MASK = const(0x0100)
_MODE_CONTIN = const(0x0000) # Continuous conversion mode
_MODE_SINGLE = const(0x0100) # Power-down single-shot mode (default)
_DR_MASK = const(0x00E0) # Values ADS1015/ADS1115
_DR_128SPS = const(0x0000) # 128 /8 samples per second
_DR_250SPS = const(0x0020) # 250 /16 samples per second
_DR_490SPS = const(0x0040) # 490 /32 samples per second
_DR_920SPS = const(0x0060) # 920 /64 samples per second
_DR_1600SPS = const(0x0080) # 1600/128 samples per second (default)
_DR_2400SPS = const(0x00A0) # 2400/250 samples per second
_DR_3300SPS = const(0x00C0) # 3300/475 samples per second
_DR_860SPS = const(0x00E0) # - /860 samples per Second
_CMODE_MASK = const(0x0010)
_CMODE_TRAD = const(0x0000) # Traditional comparator with hysteresis (default)
_CMODE_WINDOW = const(0x0010) # Window comparator
_CPOL_MASK = const(0x0008)
_CPOL_ACTVLOW = const(0x0000) # ALERT/RDY pin is low when active (default)
_CPOL_ACTVHI = const(0x0008) # ALERT/RDY pin is high when active
_CLAT_MASK = const(0x0004) # Determines if ALERT/RDY pin latches once asserted
_CLAT_NONLAT = const(0x0000) # Non-latching comparator (default)
_CLAT_LATCH = const(0x0004) # Latching comparator
_CQUE_MASK = const(0x0003)
_CQUE_1CONV = const(0x0000) # Assert ALERT/RDY after one conversions
_CQUE_2CONV = const(0x0001) # Assert ALERT/RDY after two conversions
_CQUE_4CONV = const(0x0002) # Assert ALERT/RDY after four conversions
# Disable the comparator and put ALERT/RDY in high state (default)
_CQUE_NONE = const(0x0003)
_GAINS = (
_PGA_6_144V, # 2/3x
_PGA_4_096V, # 1x
_PGA_2_048V, # 2x
_PGA_1_024V, # 4x
_PGA_0_512V, # 8x
_PGA_0_256V # 16x
)
_GAINS_V = (
6.144, # 2/3x
4.096, # 1x
2.048, # 2x
1.024, # 4x
0.512, # 8x
0.256 # 16x
)
_CHANNELS = {
(0, None): _MUX_SINGLE_0,
(1, None): _MUX_SINGLE_1,
(2, None): _MUX_SINGLE_2,
(3, None): _MUX_SINGLE_3,
(0, 1): _MUX_DIFF_0_1,
(0, 3): _MUX_DIFF_0_3,
(1, 3): _MUX_DIFF_1_3,
(2, 3): _MUX_DIFF_2_3,
}
_RATES = (
_DR_128SPS, # 128/8 samples per second
_DR_250SPS, # 250/16 samples per second
_DR_490SPS, # 490/32 samples per second
_DR_920SPS, # 920/64 samples per second
_DR_1600SPS, # 1600/128 samples per second (default)
_DR_2400SPS, # 2400/250 samples per second
_DR_3300SPS, # 3300/475 samples per second
_DR_860SPS # - /860 samples per Second
)
class ADS1115:
def __init__(self, i2c, address=0x48, gain=1):
self.i2c = i2c
self.address = address
self.gain = gain
self.temp2 = bytearray(2)
def _write_register(self, register, value):
self.temp2[0] = value >> 8
self.temp2[1] = value & 0xff
self.i2c.writeto_mem(self.address, register, self.temp2)
def _read_register(self, register):
self.i2c.readfrom_mem_into(self.address, register, self.temp2)
return (self.temp2[0] << 8) | self.temp2[1]
def raw_to_v(self, raw):
v_p_b = _GAINS_V[self.gain] / 32767
return raw * v_p_b
def set_conv(self, rate=4, channel1=0, channel2=None):
"""Set mode for read_rev"""
self.mode = (_CQUE_NONE | _CLAT_NONLAT |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] |
_MODE_SINGLE | _OS_SINGLE | _GAINS[self.gain] |
_CHANNELS[(channel1, channel2)])
def read(self, rate=4, channel1=0, channel2=None):
"""Read voltage between a channel and GND.
Time depends on conversion rate."""
self._write_register(_REGISTER_CONFIG, (_CQUE_NONE | _CLAT_NONLAT |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] |
_MODE_SINGLE | _OS_SINGLE | _GAINS[self.gain] |
_CHANNELS[(channel1, channel2)]))
while not self._read_register(_REGISTER_CONFIG) & _OS_NOTBUSY:
time.sleep_ms(1)
res = self._read_register(_REGISTER_CONVERT)
return res if res < 32768 else res - 65536
def read_rev(self):
"""Read voltage between a channel and GND. and then start
the next conversion."""
res = self._read_register(_REGISTER_CONVERT)
self._write_register(_REGISTER_CONFIG, self.mode)
return res if res < 32768 else res - 65536
def alert_start(self, rate=4, channel1=0, channel2=None,
threshold_high=0x4000, threshold_low=0, latched=False) :
"""Start continuous measurement, set ALERT pin on threshold."""
self._write_register(_REGISTER_LOWTHRESH, threshold_low)
self._write_register(_REGISTER_HITHRESH, threshold_high)
self._write_register(_REGISTER_CONFIG, _CQUE_1CONV |
_CLAT_LATCH if latched else _CLAT_NONLAT |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] |
_MODE_CONTIN | _GAINS[self.gain] |
_CHANNELS[(channel1, channel2)])
def conversion_start(self, rate=4, channel1=0, channel2=None):
"""Start continuous measurement, trigger on ALERT/RDY pin."""
self._write_register(_REGISTER_LOWTHRESH, 0)
self._write_register(_REGISTER_HITHRESH, 0x8000)
self._write_register(_REGISTER_CONFIG, _CQUE_1CONV | _CLAT_NONLAT |
_CPOL_ACTVLOW | _CMODE_TRAD | _RATES[rate] |
_MODE_CONTIN | _GAINS[self.gain] |
_CHANNELS[(channel1, channel2)])
def alert_read(self):
"""Get the last reading from the continuous measurement."""
res = self._read_register(_REGISTER_CONVERT)
return res if res < 32768 else res - 65536
class ADS1113(ADS1115):
def __init__(self, i2c, address=0x48):
super().__init__(i2c, address, 1)
def raw_to_v(self, raw):
return super().raw_to_v(raw)
def read(self, rate=4):
return super().read(rate, 0, 1)
def alert_start(self, rate=4, threshold_high=0x4000, threshold_low=0, latched=False):
return super().alert_start(rate, 0, 1, threshold_high, threshold_low, latched)
def alert_read(self):
return super().alert_read()
class ADS1114(ADS1115):
def __init__(self, i2c, address=0x48, gain=1):
super().__init__(i2c, address, gain)
def raw_to_v(self, raw):
return super().raw_to_v(raw)
def read(self, rate=4):
return super().read(rate, 0, 1)
def alert_start(self, rate=4, threshold_high=0x4000, threshold_low=0, latched=False):
return super().alert_start(rate, 0, 1, threshold_high,
threshold_low, latched)
def alert_read(self):
return super().alert_read()
class ADS1015(ADS1115):
def __init__(self, i2c, address=0x48, gain=1):
super().__init__(i2c, address, gain)
def raw_to_v(self, raw):
return super().raw_to_v(raw << 4)
def read(self, rate=4, channel1=0, channel2=None):
return super().read(rate, channel1, channel2) >> 4
def alert_start(self, rate=4, channel1=0, channel2=None, threshold_high=0x400,
threshold_low=0, latched=False):
return super().alert_start(rate, channel1, channel2, threshold_high << 4,
threshold_low << 4, latched)
def alert_read(self):
return super().alert_read() >> 4