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139 lines
2.9 KiB
139 lines
2.9 KiB
CMA3000-D0x Accelerometer |
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Supported chips: |
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* VTI CMA3000-D0x |
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Datasheet: |
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CMA3000-D0X Product Family Specification 8281000A.02.pdf |
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<http://www.vti.fi/en/> |
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:Author: Hemanth V <[email protected]> |
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Description |
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----------- |
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CMA3000 Tri-axis accelerometer supports Motion detect, Measurement and |
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Free fall modes. |
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Motion Detect Mode: |
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Its the low power mode where interrupts are generated only |
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when motion exceeds the defined thresholds. |
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Measurement Mode: |
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This mode is used to read the acceleration data on X,Y,Z |
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axis and supports 400, 100, 40 Hz sample frequency. |
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Free fall Mode: |
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This mode is intended to save system resources. |
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Threshold values: |
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Chip supports defining threshold values for above modes |
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which includes time and g value. Refer product specifications for |
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more details. |
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CMA3000 chip supports mutually exclusive I2C and SPI interfaces for |
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communication, currently the driver supports I2C based communication only. |
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Initial configuration for bus mode is set in non volatile memory and can later |
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be modified through bus interface command. |
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Driver reports acceleration data through input subsystem. It generates ABS_MISC |
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event with value 1 when free fall is detected. |
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Platform data need to be configured for initial default values. |
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Platform Data |
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------------- |
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fuzz_x: |
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Noise on X Axis |
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fuzz_y: |
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Noise on Y Axis |
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fuzz_z: |
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Noise on Z Axis |
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g_range: |
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G range in milli g i.e 2000 or 8000 |
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mode: |
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Default Operating mode |
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mdthr: |
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Motion detect g range threshold value |
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mdfftmr: |
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Motion detect and free fall time threshold value |
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ffthr: |
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Free fall g range threshold value |
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Input Interface |
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--------------- |
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Input driver version is 1.0.0 |
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Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0 |
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Input device name: "cma3000-accelerometer" |
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Supported events:: |
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Event type 0 (Sync) |
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Event type 3 (Absolute) |
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Event code 0 (X) |
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Value 47 |
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Min -8000 |
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Max 8000 |
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Fuzz 200 |
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Event code 1 (Y) |
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Value -28 |
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Min -8000 |
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Max 8000 |
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Fuzz 200 |
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Event code 2 (Z) |
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Value 905 |
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Min -8000 |
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Max 8000 |
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Fuzz 200 |
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Event code 40 (Misc) |
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Value 0 |
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Min 0 |
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Max 1 |
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Event type 4 (Misc) |
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Register/Platform parameters Description |
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---------------------------------------- |
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mode:: |
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0: power down mode |
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1: 100 Hz Measurement mode |
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2: 400 Hz Measurement mode |
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3: 40 Hz Measurement mode |
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4: Motion Detect mode (default) |
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5: 100 Hz Free fall mode |
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6: 40 Hz Free fall mode |
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7: Power off mode |
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grange:: |
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2000: 2000 mg or 2G Range |
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8000: 8000 mg or 8G Range |
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mdthr:: |
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X: X * 71mg (8G Range) |
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X: X * 18mg (2G Range) |
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mdfftmr:: |
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X: (X & 0x70) * 100 ms (MDTMR) |
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(X & 0x0F) * 2.5 ms (FFTMR 400 Hz) |
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(X & 0x0F) * 10 ms (FFTMR 100 Hz) |
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ffthr:: |
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X: (X >> 2) * 18mg (2G Range) |
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X: (X & 0x0F) * 71 mg (8G Range)
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