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1CMA3000-D0x Accelerometer
2=========================
3
4Supported chips:
5* VTI CMA3000-D0x
6
7Datasheet:
8 CMA3000-D0X Product Family Specification 8281000A.02.pdf
9 <http://www.vti.fi/en/>
10
11:Author: Hemanth V <hemanthv@ti.com>
12
13
14Description
15-----------
16
17CMA3000 Tri-axis accelerometer supports Motion detect, Measurement and
18Free fall modes.
19
20Motion Detect Mode:
21 Its the low power mode where interrupts are generated only
22 when motion exceeds the defined thresholds.
23
24Measurement Mode:
25 This mode is used to read the acceleration data on X,Y,Z
26 axis and supports 400, 100, 40 Hz sample frequency.
27
28Free fall Mode:
29 This mode is intended to save system resources.
30
31Threshold values:
32 Chip supports defining threshold values for above modes
33 which includes time and g value. Refer product specifications for
34 more details.
35
36CMA3000 chip supports mutually exclusive I2C and SPI interfaces for
37communication, currently the driver supports I2C based communication only.
38Initial configuration for bus mode is set in non volatile memory and can later
39be modified through bus interface command.
40
41Driver reports acceleration data through input subsystem. It generates ABS_MISC
42event with value 1 when free fall is detected.
43
44Platform data need to be configured for initial default values.
45
46Platform Data
47-------------
48
49fuzz_x:
50 Noise on X Axis
51
52fuzz_y:
53 Noise on Y Axis
54
55fuzz_z:
56 Noise on Z Axis
57
58g_range:
59 G range in milli g i.e 2000 or 8000
60
61mode:
62 Default Operating mode
63
64mdthr:
65 Motion detect g range threshold value
66
67mdfftmr:
68 Motion detect and free fall time threshold value
69
70ffthr:
71 Free fall g range threshold value
72
73Input Interface
74---------------
75
76Input driver version is 1.0.0
77Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0
78Input device name: "cma3000-accelerometer"
79
80Supported events::
81
82 Event type 0 (Sync)
83 Event type 3 (Absolute)
84 Event code 0 (X)
85 Value 47
86 Min -8000
87 Max 8000
88 Fuzz 200
89 Event code 1 (Y)
90 Value -28
91 Min -8000
92 Max 8000
93 Fuzz 200
94 Event code 2 (Z)
95 Value 905
96 Min -8000
97 Max 8000
98 Fuzz 200
99 Event code 40 (Misc)
100 Value 0
101 Min 0
102 Max 1
103 Event type 4 (Misc)
104
105
106Register/Platform parameters Description
107----------------------------------------
108
109mode::
110
111 0: power down mode
112 1: 100 Hz Measurement mode
113 2: 400 Hz Measurement mode
114 3: 40 Hz Measurement mode
115 4: Motion Detect mode (default)
116 5: 100 Hz Free fall mode
117 6: 40 Hz Free fall mode
118 7: Power off mode
119
120grange::
121
122 2000: 2000 mg or 2G Range
123 8000: 8000 mg or 8G Range
124
125mdthr::
126
127 X: X * 71mg (8G Range)
128 X: X * 18mg (2G Range)
129
130mdfftmr::
131
132 X: (X & 0x70) * 100 ms (MDTMR)
133 (X & 0x0F) * 2.5 ms (FFTMR 400 Hz)
134 (X & 0x0F) * 10 ms (FFTMR 100 Hz)
135
136ffthr::
137
138 X: (X >> 2) * 18mg (2G Range)
139 X: (X & 0x0F) * 71 mg (8G Range)