0001 CMA3000-D0x Accelerometer
0002 =========================
0003
0004 Supported chips:
0005 * VTI CMA3000-D0x
0006
0007 Datasheet:
0008 CMA3000-D0X Product Family Specification 8281000A.02.pdf
0009 <http://www.vti.fi/en/>
0010
0011 :Author: Hemanth V <hemanthv@ti.com>
0012
0013
0014 Description
0015 -----------
0016
0017 CMA3000 Tri-axis accelerometer supports Motion detect, Measurement and
0018 Free fall modes.
0019
0020 Motion Detect Mode:
0021 Its the low power mode where interrupts are generated only
0022 when motion exceeds the defined thresholds.
0023
0024 Measurement Mode:
0025 This mode is used to read the acceleration data on X,Y,Z
0026 axis and supports 400, 100, 40 Hz sample frequency.
0027
0028 Free fall Mode:
0029 This mode is intended to save system resources.
0030
0031 Threshold values:
0032 Chip supports defining threshold values for above modes
0033 which includes time and g value. Refer product specifications for
0034 more details.
0035
0036 CMA3000 chip supports mutually exclusive I2C and SPI interfaces for
0037 communication, currently the driver supports I2C based communication only.
0038 Initial configuration for bus mode is set in non volatile memory and can later
0039 be modified through bus interface command.
0040
0041 Driver reports acceleration data through input subsystem. It generates ABS_MISC
0042 event with value 1 when free fall is detected.
0043
0044 Platform data need to be configured for initial default values.
0045
0046 Platform Data
0047 -------------
0048
0049 fuzz_x:
0050 Noise on X Axis
0051
0052 fuzz_y:
0053 Noise on Y Axis
0054
0055 fuzz_z:
0056 Noise on Z Axis
0057
0058 g_range:
0059 G range in milli g i.e 2000 or 8000
0060
0061 mode:
0062 Default Operating mode
0063
0064 mdthr:
0065 Motion detect g range threshold value
0066
0067 mdfftmr:
0068 Motion detect and free fall time threshold value
0069
0070 ffthr:
0071 Free fall g range threshold value
0072
0073 Input Interface
0074 ---------------
0075
0076 Input driver version is 1.0.0
0077 Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0
0078 Input device name: "cma3000-accelerometer"
0079
0080 Supported events::
0081
0082 Event type 0 (Sync)
0083 Event type 3 (Absolute)
0084 Event code 0 (X)
0085 Value 47
0086 Min -8000
0087 Max 8000
0088 Fuzz 200
0089 Event code 1 (Y)
0090 Value -28
0091 Min -8000
0092 Max 8000
0093 Fuzz 200
0094 Event code 2 (Z)
0095 Value 905
0096 Min -8000
0097 Max 8000
0098 Fuzz 200
0099 Event code 40 (Misc)
0100 Value 0
0101 Min 0
0102 Max 1
0103 Event type 4 (Misc)
0104
0105
0106 Register/Platform parameters Description
0107 ----------------------------------------
0108
0109 mode::
0110
0111 0: power down mode
0112 1: 100 Hz Measurement mode
0113 2: 400 Hz Measurement mode
0114 3: 40 Hz Measurement mode
0115 4: Motion Detect mode (default)
0116 5: 100 Hz Free fall mode
0117 6: 40 Hz Free fall mode
0118 7: Power off mode
0119
0120 grange::
0121
0122 2000: 2000 mg or 2G Range
0123 8000: 8000 mg or 8G Range
0124
0125 mdthr::
0126
0127 X: X * 71mg (8G Range)
0128 X: X * 18mg (2G Range)
0129
0130 mdfftmr::
0131
0132 X: (X & 0x70) * 100 ms (MDTMR)
0133 (X & 0x0F) * 2.5 ms (FFTMR 400 Hz)
0134 (X & 0x0F) * 10 ms (FFTMR 100 Hz)
0135
0136 ffthr::
0137
0138 X: (X >> 2) * 18mg (2G Range)
0139 X: (X & 0x0F) * 71 mg (8G Range)
