三轴加速度传感器使用说明

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三轴加速度传感器安全操作及保养规程

三轴加速度传感器安全操作及保养规程三轴加速度传感器是一种常用的测试设备，它被广泛应用于各种领域。

为确保它能够正常工作并延长其使用寿命，需要按照以下规程进行安全操作及保养。

安全操作规程1. 安装在安装传感器之前，需确保其适用于相应的设备。

适当安装传感器会极大地提高其检测精度和可靠性。

安装时需要注意以下几点：1.确认传感器安装环境的温度、湿度和气压符合传感器的工作要求。

例如，有些传感器可能无法正常工作在极端的高温或低温环境中。

2.传感器应该被安装在合适的位置以避免外部冲击或损伤，并保证其对测量物的检测效果不受影响。

3.安装三轴加速度传感器时，应考虑设备结构和传感器的相对位置，以确保传感器能够正确测量受力情况。

2. 操作在使用传感器进行测量时，务必遵循以下操作规程：1.仔细阅读并遵守传感器的安装和操作手册。

2.在进行任何操作之前，确保所有设备都已正确连接，传感器处于正确的位置，且连线无异常。

此外，确保所使用的设备均符合相应的规定，并已通过检验。

3.操作期间，应注意及时记录测量结果，及时检查测量结果的可靠性，并且随时了解测量状态以及可能的问题。

如果有任何异常请及时排除。

3. 维护维护传感器是确保其正常运行和延长其使用寿命的关键。

以下是应注意的事项：1.周期性检查传感器和连接器，并确保其均正常工作。

此外，对任何损坏或磨损的组件和设备都应及时更换或修复。

2.传感器应定期校准以确保其准确性和可靠性，并且要将其校准数据记录下来以方便日后比较。

3.在传感器运输或存储时，应将其放置在干燥，防尘，不易受外部撞击的地方。

保养规程如下是三轴加速度传感器的保养规程：1. 清洁传感器可能在使用过程中受到不同程度的物理环境影响，如温度、湿度、灰尘等，所以必须经常清洗。

1.使用棉布等软质材料擦拭传感器表面，注意不要使用有机化学物质，以免破坏传感器表面涂层。

2.如果三轴加速度传感器有其他无法通过擦拭清洗的物质或污垢，可以使用一个稀释后的洗涤剂和擦拭布进行清洗。

Analog Devices ADXL335 三轴加速度传感器说明书

Small, Low Power, 3-Axis ±3 gAccelerometerADXL335Rev. BInformation furnished by Analog Devices is believed to be accurate and reliable. However , no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. T rademarks and registered trademarks are the property of their respective owners.One Technology Way, P.O. Box 9106, Norwood, M A 02062-9106, U.S.A.Tel: 781.329.4700 Fax: 781.461.3113 ©2009–2010 Analog Devices, Inc. All rights reserved.FEATURES3-axis sensingSmall, low profile package4 mm × 4 mm × 1.45 mm LFCSP Low power : 350 μA (typical)Single-supply operation: 1.8 V to 3.6 V 10,000 g shock survivalExcellent temperature stabilityBW adjustment with a single capacitor per axis RoHS/WEEE lead-free compliantAPPLICATIONSCost sensitive, low power, motion- and tilt-sensing applications Mobile devices Gaming systemsDisk drive protection Image stabilizationSports and health devicesGENERAL DESCRIPTIONThe ADXL335 is a small, thin, low power, complete 3-axis accel-erometer with signal conditioned voltage outputs. The product measures acceleration with a minimum full-scale range of ±3 g . It can measure the static acceleration of gravity in tilt-sensing applications, as well as dynamic acceleration resulting from motion, shock, or vibration.The user selects the bandwidth of the accelerometer using the C X , C Y , and C Z capacitors at the X OUT , Y OUT , and Z OUT pins. Bandwidths can be selected to suit the application, with a range of 0.5 Hz to 1600 Hz for the X and Y axes, and a range of 0.5 Hz to 550 Hz for the Z axis.The ADXL335 is available in a small, low profile, 4 mm ×4 mm × 1.45 mm, 16-lead, plastic lead frame chip scale package (LFCSP_LQ).FUNCTIONAL BLOCK DIAGRAMC DCFigure 1.ADXL335Rev. B | Page 2 of 16TABLE OF CONTENTSFeatures .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications ..................................................................................... 3 Absolute Maximum Ratings ............................................................ 4 ESD Caution .................................................................................. 4 Pin Configuration and Function Descriptions ............................. 5 Typical Performance Characteristics ............................................. 6 Theory of Operation ...................................................................... 10 Mechanical Sensor ...................................................................... 10 Performance ................................................................................ 10 Applications Information .............................................................. 11 Power Supply Decoupling ......................................................... 11 Setting the Bandwidth Using C X , C Y , and C Z .......................... 11 Self-Test ....................................................................................... 11 Design Trade-Offs for Selecting Filter Characteristics: The Noise/BW Trade-Off .................................................................. 11 Use with Operating V oltages Other Than 3 V ........................... 12 Axes of Acceleration Sensitivity ............................................... 12 Layout and Design Recommendations ................................... 13 Outline Dimensions ....................................................................... 14 Ordering Guide .. (14)REVISION HISTORY1/10—Rev. A to Rev. BChanges to Figure 21 (9)7/09—Rev. 0 to Rev. AChanges to Figure 22 ........................................................................ 9 Changes to Outline Dimensions (14)1/09—Revision 0: Initial VersionADXL335Rev. B | Page 3 of 16SPECIFICATIONST A = 25°C, V S = 3 V , C X = C Y = C Z = 0.1 μF, acceleration = 0 g , unless otherwise noted. All minimum and maximum specifications are guaranteed. Typical specifications are not guaranteed. Table 1.Parameter Conditions M in Typ M ax Unit SENSOR INPUT Each axisMeasurement Range ±3 ±3.6g Nonlinearity % of full scale ±0.3 % Package Alignment Error ±1 Degrees Interaxis Alignment Error ±0.1 DegreesCross-Axis Sensitivity 1±1 % SENSITIVITY (RATIOMETRIC)2 Each axis Sensitivity at X OUT , Y OUT , Z OUT V S = 3 V 270 300 330 mV/gSensitivity Change Due to Temperature 3V S = 3 V ±0.01 %/°C ZERO g BIAS LEVEL (RATIOMETRIC) 0 g Voltage at X OUT , Y OUT V S = 3 V 1.35 1.5 1.65 V 0 g Voltage at Z OUT V S = 3 V 1.2 1.5 1.8 V 0 g Offset vs. Temperature ±1 m g /°C NOISE PERFORMANCE Noise Density X OUT , Y OUT 150 μg /√Hz rms Noise Density Z OUT 300 μg /√Hz rms FREQUENCY RESPONSE 4 Bandwidth X OUT , Y OUT 5 No external filter 1600 Hz Bandwidth Z OUT 5 No external filter 550 Hz R FILT Tolerance 32 ± 15% kΩ Sensor Resonant Frequency 5.5 kHz SELF-TEST 6 Logic Input Low +0.6 V Logic Input High +2.4 V ST Actuation Current +60 μA Output Change at X OUT Self-Test 0 to Self-Test 1 −150 −325 −600 mV Output Change at Y OUT Self-Test 0 to Self-Test 1 +150 +325 +600 mV Output Change at Z OUT Self-Test 0 to Self-Test 1 +150 +550 +1000 mV OUTPUT AMPLIFIER Output Swing Low No load 0.1 V Output Swing High No load 2.8 V POWER SUPPLY Operating Voltage Range 1.8 3.6 V Supply Current V S = 3 V 350 μA Turn-On Time 7 No external filter 1 ms TEMPERATURE Operating Temperature Range −40 +85 °C1 Defined as coupling between any two axes. 2Sensitivity is essentially ratiometric to V S . 3Defined as the output change from ambient-to-maximum temperature or ambient-to-minimum temperature. 4Actual frequency response controlled by user-supplied external filter capacitors (C X , C Y , C Z ). 5Bandwidth with external capacitors = 1/(2 × π × 32 kΩ × C). For C X , C Y = 0.003 μF, bandwidth = 1.6 kHz. For C Z = 0.01 μF, bandwidth = 500 Hz. For C X , C Y , C Z = 10 μF, bandwidth = 0.5 Hz. 6Self-test response changes cubically with V S . 7Turn-on time is dependent on C X , C Y , C Z and is approximately 160 × C X or C Y or C Z + 1 ms, where C X , C Y , C Z are in microfarads (μF).ADXL335Rev. B | Page 4 of 16ABSOLUTE MAXIMUM RATINGSTable 2.Parameter Rating Acceleration (Any Axis, Unpowered) 10,000 g Acceleration (Any Axis, Powered) 10,000 g V S −0.3 V to +3.6 V All Other Pins (COM − 0.3 V) to (V S + 0.3 V)Output Short-Circuit Duration(Any Pin to Common)Indefinite Temperature Range (Powered) −55°C to +125°C Temperature Range (Storage) −65°C to +150°CStresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operationalsection of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.ESD CAUTIONADXL335Rev. B | Page 5 of 16PIN CONFIGURATION AND FUNCTION DESCRIPTIONS07808-003NOTES1. EXPOSED PAD IS NOT INTERNALLYCONNECTED BUT SHOULD BE SOLDERED FOR MECHANICAL INTEGRITY.NC = NO CONNECTNCST COM NCX OUT NC Y OUT NCC O MC O MC O MZ O U TN CV SV SN CFigure 2. Pin ConfigurationTable 3. Pin Function DescriptionsPin No. MnemonicDescription1 NC No Connect.12 ST Self-Test.3 C O M Common.4 NC No Connect.15 C O M Common.6 C O M Common.7 C O M Common.8 Z OUTZ Channel Output.9 NC No Connect.110 Y OUTY Channel Output.11 NC No Connect. 112 X OUTX Channel Output.13 NC No Connect. 114 V S Supply Voltage (1.8 V to 3.6 V). 15 V SSupply Voltage (1.8 V to 3.6 V).16 NC No Connect. 1EP Exposed PadNot internally connected. Solder for mechanical integrity.1NC pins are not internally connected and can be tied to COM pins, unless otherwise noted.ADXL335Rev. B | Page 6 of 16TYPICAL PERFORMANCE CHARACTERISTICSN > 1000 for all typical performance plots, unless otherwise noted.500102030401.42 1.44 1.46 1.48 1.50 1.52 1.54 1.56 1.58% O F P O P U L A T I O NOUTPUT (V)07808-005Figure 3. X-Axis Zero g Bias at 25°C, V S = 3 V500102030401.42 1.44 1.46 1.48 1.50 1.52 1.54 1.56 1.58% O F P O P U L A T I O NOUTPUT (V)07808-006Figure 4. Y-Axis Zero g Bias at 25°C, V S = 3 V1.42 1.44 1.46 1.48 1.50 1.52 1.54 1.56 1.58% O F P O P U L A T I O NOUTPUT (V)07808-0070510152025Figure 5. Z-Axis Zero g Bias at 25°C, V S = 3 V % O F P O P U L A T I O NVOLTS (V)07808-00810203040–0.40–0.38–0.36–0.34–0.32–0.30–0.28–0.26Figure 6. X-Axis Self-Test Response at 25°C, V S = 3 V% O F P O P U L A T I O NVOLTS (V)07808-00910203050400.260.280.300.320.340.360.380.40Figure 7. Y-Axis Self-Test Response at 25°C, V S = 3 V% O F P O P U L A T I O NVOLTS (V)07808-010102030400.480.500.520.540.560.580.600.62Figure 8. Z-Axis Self-Test Response at 25°C, V S = 3 VADXL335Rev. B | Page 7 of 16% O F P O P U L A T I O NTEMPERATURE COEFFICIENT (m g/°C)51015202530–3.0–2.5–2.0–1.5–1.0–0.500.5 1.0 1.5 2.0 2.5 3.007808-011Figure 9. X-Axis Zero g Bias Temperature Coefficient, V S = 3 V% O F P O P U L A T I O NTEMPERATURE COEFFICIENT (m g /°C)10204030–3.0–2.5–2.0–1.5–1.0–0.500.5 1.0 1.5 2.0 2.53.007808-012Figure 10. Y-Axis Zero g Bias Temperature Coefficient, V S = 3 V% O F P O P U L A T I O NTEMPERATURE COEFFICIENT (m g/°C)510152007808-013Figure 11. Z-Axis Zero g Bias Temperature Coefficient, V S = 3 V1.451.461.471.481.491.501.511.521.531.541.55TEMPERATURE (°C)O U T P U T (V )07808-014Figure 12. X-Axis Zero g Bias vs. Temperature—Eight Parts Soldered to PCB1.451.461.471.481.491.501.511.521.531.541.55–40–30–20–100102030405060708090100TEMPERATURE (°C)O U T P U T (V )07808-015Figure 13. Y-Axis Zero g Bias vs. Temperature—Eight Parts Soldered to PCB1.301.321.341.361.381.401.421.441.461.481.50–40–30–20–100102030405060708090100TEMPERATURE (°C)O U T P U T (V )07808-016Figure 14. Z-Axis Zero g Bias vs. Temperature—Eight Parts Soldered to PCBADXL335Rev. B | Page 8 of 16% O F P O P U L A T I O NSENSITIVITY (V/g )51015200.2850.2880.2910.2940.2970.3000.3030.3060.3090.3120.31507808-017Figure 15. X-Axis Sensitivity at 25°C, V S = 3 V% O F P O P U L A T I O NSENSITIVITY (V/g )051015200.2850.2880.2910.2940.2970.3000.3030.3060.3090.3120.3152507808-018Figure 16. Y-Axis Sensitivity at 25°C, V S = 3 V% O F P O P U L A T I O NSENSITIVITY (V/g )51015202507808-019Figure 17. Z-Axis Sensitivity at 25°C, V S= 3 V0.2800.2850.2900.2950.3000.3050.3100.3150.320TEMPERATURE (°C)S E N S I T I V I T Y (V /g )07808-020Figure 18. X-Axis Sensitivity vs. Temperature—Eight Parts Soldered to PCB, V S= 3 V0.2800.2850.2900.2950.3000.3050.3100.3150.320–40–30–20–100102030405060708090100TEMPERATURE (°C)S E N S I T I V I T Y (V /g )07808-021Figure 19. Y-Axis Sensitivity vs. Temperature—Eight Parts Soldered to PCB, V S= 3 V0.2800.2850.2900.2950.3000.3050.3100.3150.320–40–30–20–100102030405060708090100TEMPERATURE (°C)S E N S I T I V I T Y (V /g )07808-022Figure 20. Z-Axis Sensitivity vs. Temperature—Eight Parts Soldered to PCB, V S = 3 VADXL335Rev. B | Page 9 of 16SUPPLY (V)C U R R E N T (µA )0100501502002503003501.52.0 2.53.0 3.54.007808-023Figure 21. Typical Current Consumption vs. Supply VoltageTIME (1ms/DIV)07808-024Figure 22. Typical Turn-On Time, V S = 3 VADXL335Rev. B | Page 10 of 16THEORY OF OPERATIONThe ADXL335 is a complete 3-axis acceleration measurement system. The ADXL335 has a measurement range of ±3 g mini-mum. It contains a polysilicon surface-micromachined sensor and signal conditioning circuitry to implement an open-loop acceleration measurement architecture. The output signals are analog voltages that are proportional to acceleration. The accelerometer can measure the static acceleration of gravity in tilt-sensing applications as well as dynamic acceleration resulting from motion, shock, or vibration.The sensor is a polysilicon surface-micromachined structure built on top of a silicon wafer. Polysilicon springs suspend the structure over the surface of the wafer and provide a resistance against acceleration forces. Deflection of the structure is meas-ured using a differential capacitor that consists of independent fixed plates and plates attached to the moving mass. The fixed plates are driven by 180° out-of-phase square waves. Acceleration deflects the moving mass and unbalances the differential capacitor resulting in a sensor output whose amplitude is proportional to acceleration. Phase-sensitive demodulation techniques are then used to determine the magnitude and direction of the acceleration. The demodulator output is amplified and brought off-chip through a 32 kΩ resistor. The user then sets the signalbandwidth of the device by adding a capacitor. This filtering improves measurement resolution and helps prevent aliasing.MECHANICAL SENSORThe ADXL335 uses a single structure for sensing the X, Y, and Z axes. As a result, the three axes’ sense directions are highly orthogonal and have little cross-axis sensitivity. Mechanical misalignment of the sensor die to the package is the chief source of cross-axis sensitivity. Mechanical misalignment can, of course, be calibrated out at the system level.PERFORMANCERather than using additional temperature compensation circui-try, innovative design techniques ensure that high performance is built in to the ADXL335. As a result, there is no quantization error or nonmonotonic behavior, and temperature hysteresis is very low (typically less than 3 m g over the −25°C to +70°C temperature range).ADXL335 APPLICATIONS INFORMATIONPOWER SUPPLY DECOUPLINGFor most applications, a single 0.1 μF capacitor, C DC, placedclose to the ADXL335 supply pins adequately decouples the accelerometer from noise on the power supply. However, in applications where noise is present at the 50 kHz internal clock frequency (or any harmonic thereof), additional care in power supply bypassing is required because this noise can cause errorsin acceleration measurement.If additional decoupling is needed, a 100 Ω (or smaller) resistoror ferrite bead can be inserted in the supply line. Additionally, a larger bulk bypass capacitor (1 μF or greater) can be added in parallel to C DC. Ensure that the connection from the ADXL335 ground to the power supply ground is low impedance becausenoise transmitted through ground has a similar effect to noise transmitted through V S.SETTING THE BANDWIDTH USING C X, C Y, AND C ZThe ADXL335 has provisions for band limiting the X OUT, Y OUT,and Z OUT pins. Capacitors must be added at these pins to imple-ment low-pass filtering for antialiasing and noise reduction. The equation for the 3 dB bandwidth isF−3 dB = 1/(2π(32 kΩ) × C(X, Y, Z))or more simplyF–3 dB = 5 μF/C(X, Y, Z)The tolerance of the internal resistor (R FILT) typically varies asmuch as ±15% of its nominal value (32 kΩ), and the bandwidth varies accordingly. A minimum capacitance of 0.0047 μF for C X,C Y, and C Z is recommended in all cases.Table 4. Filter Capacitor Selection, C X, C Y, and C ZBandwidth (Hz) Capacitor (μF)1 4.7 10 0.47 50 0.10 100 0.05 200 0.027 500 0.01SELF-TESTThe ST pin controls the self-test feature. When this pin is set toV S, an electrostatic force is exerted on the accelerometer beam.The resulting movement of the beam allows the user to test ifthe accelerometer is functional. The typical change in outputis −1.08 g (corresponding to −325 mV) in the X-axis, +1.08 g(or +325 mV) on the Y-axis, and +1.83 g (or +550 mV) on theZ-axis. This ST pin can be left open-circuit or connected tocommon (COM) in normal use. Never expose the ST pin to voltages greater than V S + 0.3 V.If this cannot be guaranteed due to the system design (for instance, if there are multiple supply voltages), then a lowV F clamping diode between ST and V S is recommended. DESIGN TRADE-OFFS FOR SELECTING FILTER CHARACTERISTICS: THE NOISE/BW TRADE-OFF The selected accelerometer bandwidth ultimately determines the measurement resolution (smallest detectable acceleration). Filtering can be used to lower the noise floor to improve the resolution of the accelerometer. Resolution is dependent on the analog filter bandwidth at X OUT, Y OUT, and Z OUT.The output of the ADXL335 has a typical bandwidth of greater than 500 Hz. The user must filter the signal at this point to limit aliasing errors. The analog bandwidth must be no more than half the analog-to-digital sampling frequency to minimize aliasing. The analog bandwidth can be further decreased to reduce noise and improve resolution.The ADXL335 noise has the characteristics of white Gaussian noise, which contributes equally at all frequencies and is described in terms of μg/√Hz (the noise is proportional to the square root of the accelerometer bandwidth). The user should limit bandwidth to the lowest frequency needed by the applica-tion to maximize the resolution and dynamic range of the accelerometer.With the single-pole, roll-off characteristic, the typical noise of the ADXL335 is determined by)1.6(××=BWDensityNoiseNoisermsIt is often useful to know the peak value of the noise. Peak-to-peak noise can only be estimated by statistical methods. Table 5 is useful for estimating the probabilities of exceeding various peak values, given the rms value.Table 5. Estimation of Peak-to-Peak NoisePeak-to-Peak Value% of Time That Noise ExceedsNominal Peak-to-Peak Value2 × rms 324 × rms 4.66 × rms 0.278 × rms 0.006ADXL335USE WITH OPERATING VOLTAGES OTHER THAN 3 VThe ADXL335 is tested and specified at V S = 3 V; however, it can be powered with V S as low as 1.8 V or as high as 3.6 V . Note that some performance parameters change as the supply voltage is varied.The ADXL335 output is ratiometric, therefore, the output sensitivity (or scale factor) varies proportionally to the supply voltage. At V S = 3.6 V , the output sensitivity is typi- cally 360 mV/g . At V S = 2 V , the output sensitivity is typically 195 mV/g .The zero g bias output is also ratiometric, thus the zero g output is nominally equal to V S /2 at all supply voltages. The output noise is not ratiometric but is absolute in volts; therefore, the noise density decreases as the supply voltage increases. This is because the scale factor (mV/g ) increases while the noise voltage remains constant. At V S = 3.6 V , the X-axis and Y-axis noise density is typically 120 μg /√Hz, whereas at V S = 2 V , the X-axis and Y-axis noise density is typically 270 μg /√Hz.Self-test response in g is roughly proportional to the square of the supply voltage. However, when ratiometricity of sensitivity is factored in with supply voltage, the self-test response in volts is roughly proportional to the cube of the supply voltage. For example, at V S = 3.6 V , the self-test response for the ADXL335 is approximately −560 mV for the X-axis, +560 mV for the Y-axis, and +950 mV for the Z-axis.At V S = 2 V , the self-test response is approximately −96 mV for the X-axis, +96 mV for the Y-axis, and −163 mV for the Z-axis. The supply current decreases as the supply voltage decreases. Typical current consumption at V S = 3.6 V is 375 μA, and typi-cal current consumption at V S = 2 V is 200 μA.AXES OF ACCELERATION SENSITIVITYA X07808-025Figure 23. Axes of Acceleration Sensitivity; Corresponding Output VoltageIncreases When Accelerated Along the Sensitive Axis.X OUT = –1g Y OUT = 0g Z= 0gGRAVITYX OUT = 0g Y OUT = 1g Z OUT = 0gX OUT = 0g Y OUT = –1g Z OUT = 0gX OUT = 1g YOUT = 0gZ OUT = 0gX OUT = 0g Y OUT = 0g Z OUT = 1g X OUT = 0g Y OUT = 0g Z OUT = –1g07808-026Figure 24. Output Response vs. Orientation to GravityADXL335LAYOUT AND DESIGN RECOMMENDATIONSThe recommended soldering profile is shown in Figure 25 followed by a description of the profile features in Table 6. The recommended PCB layout or solder land drawing is shown in Figure 26.07808-002T E M P E R A T U R ETIMETFigure 25. Recommended Soldering ProfileTable 6. Recommended Soldering ProfileProfile Feature Sn63/Pb37 Pb-Free Average Ramp Rate (T L to T P ) 3°C/sec max 3°C/sec maxPreheat Minimum Temperature (T SMIN ) 100°C 150°C Maximum Temperature (T SMAX ) 150°C 200°C Time (T SMIN to T SMAX )(t S ) 60 sec to 120 sec 60 sec to 180 sec T SMAX to T L Ramp-Up Rate 3°C/sec max 3°C/sec max Time Maintained Above Liquidous (T L ) Liquidous Temperature (T L ) 183°C 217°C Time (t L ) 60 sec to 150 sec 60 sec to 150 sec Peak Temperature (T P ) 240°C + 0°C/−5°C 260°C + 0°C/−5°C Time Within 5°C of Actual Peak Temperature (t P ) 10 sec to 30 sec 20 sec to 40 sec Ramp-Down Rate 6°C/sec max 6°C/sec max Time 25°C to Peak Temperature 6 minutes max 8 minutes max0.35DIMENSIONS SHOWN IN MILLIMETERS07808Figure 26. Recommended PCB LayoutADXL335OUTLINE DIMENSIONS051909-A1.500.08PIN COMPLIANT TO JEDEC STANDARDS MO-220-WGGD.FOR PROPER CONNECTION OF THE EXPOSED PAD,REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONSSECTION OF THIS DATA SHEET.Figure 27. 16-Lead Lead Frame Chip Scale Package [LFCSP_LQ]4 mm × 4 mm Body, 1.45 mm Thick Quad(CP-16-14)Dimensions shown in millimetersORDERING GUIDEModel 1 M easurement Range Specified Voltage Temperature Range Package Description Package OptionADXL335BCPZ ±3 g 3 V −40°C to +85°C 16-Lead LFCSP_LQ CP-16-14 ADXL335BCPZ–RL ±3 g 3 V −40°C to +85°C 16-Lead LFCSP_LQ CP-16-14 ADXL335BCPZ–RL7 ±3 g 3 V −40°C to +85°C 16-Lead LFCSP_LQ CP-16-14 EVAL-ADXL335ZEvaluation Board1Z = RoHS Compliant Part.ADXL335 NOTESADXL335NOTESAnalog Devices offers specific products designated for automotive applications; please consult your local Analog Devices sales representative for details. Standard products sold by Analog Devices are not designed, intended, or approved for use in life support, implantable medical devices, transportation, nuclear, safety, or other equipment where malfunction of the product can reasonably be expected to result in personal injury, death, severe property damage, or severe environmental harm. Buyer uses or sells standard products for use in the above critical applications at Buyer's own risk and Buyer agrees to defend, indemnify, and hold harmless Analog Devices from any and all damages, claims, suits, or expenses resulting from such unintended use.©2009–2010 Analog Devices, Inc. All rights reserved. Trademarks andregistered trademarks are the property of their respective owners.D07808-0-1/10(B)。

三轴传感器自适应动态阈值法的原理及应用

三轴传感器自适应动态阈值法的原理及应用随着科技的不断发展，传感器在各个领域的应用越来越广泛。

三轴传感器作为其中的一种，被广泛应用于导航、机器人、无人驾驶等领域。

为了提高传感器的性能和适应性，自适应动态阈值法作为一种新的算法被提出并得到了广泛应用。

本文将详细介绍三轴传感器自适应动态阈值法的原理及应用。

一、三轴传感器的原理及特点三轴传感器是一种能够测量三个不同方向上的加速度的装置，通常由加速度计和加速度计读取器组成。

三轴传感器能够准确地测量物体在三个方向上的加速度变化，从而获取物体在空间中的运动状态。

三轴传感器具有精度高、稳定性好、响应速度快等特点，因此在导航、机器人、无人驾驶等领域得到了广泛应用。

二、自适应动态阈值法的原理自适应动态阈值法是一种基于机器学习算法的阈值设定方法。

该方法通过学习传感器数据，自动确定每个轴上的动态阈值。

当加速度超过该阈值时，传感器会自动调整阈值并发出报警信号。

该方法的特点是能够根据实际应用场景的变化，自适应地调整阈值，从而更好地适应不同的工作环境。

自适应动态阈值法的工作原理主要包括以下几个步骤：1. 数据采集：从三轴传感器中采集数据，包括加速度数据和时间戳数据。

2. 特征提取：从采集的数据中提取出加速度特征，如加速度的峰值、谷值等。

3. 机器学习：使用机器学习方法，如支持向量机、神经网络等，对特征数据进行训练和学习，自动确定每个轴上的动态阈值。

4. 阈值调整：当加速度超过动态阈值时，传感器会自动调整阈值并发出报警信号。

同时，传感器也会记录下每次调整后的阈值，以便后续分析和优化。

三、自适应动态阈值法在三轴传感器中的应用自适应动态阈值法在三轴传感器中的应用非常广泛，其主要应用于以下领域：1. 无人驾驶：无人驾驶车辆需要实时感知周围环境的变化，如行人、车辆等。

通过应用自适应动态阈值法，可以提高传感器的准确性和稳定性，从而提高无人驾驶的安全性。

2. 工业自动化：在工业自动化领域中，应用自适应动态阈值法可以提高设备的自动化程度和工作效率。

杭州士兰微电子股份有限公司 SC7A20 三轴微机械数字加速度传感器说明书

±2G/±4G/±8G/±16G三轴微机械数字加速度计描述SC7A20是一款高精度12bit数字三轴加速度传感器芯片，内置功能更丰富，功耗更低，体积更小，测量更精确。

芯片通过I²C/SPI接口与MCU通信，加速度测量数据以中断方式或查询方式获取。

INT1和INT2中断管脚提供多种内部自动检测的中断信号，适应多种运动检测场合，中断源包括6D/4D方向检测中断信号、自由落体检测中断信号、睡眠和唤醒检测中断信号、单击和双击检测中断信号。

芯片内置高精度校准模块，对传感器的失调误差和增益误差进行精确补偿。

±2G、±4G、±8G和±16G四种可调整的全量程测量范围，灵活测量外部加速度，输出数据率1HZ和400HZ间可选。

芯片内置自测试功能允许客户系统测试时检测系统功能，省去复杂的转台测试。

芯片内置产品倾斜校准功能，对贴片和板卡安装导致的倾斜进行补偿，不占系统资源，系统文件升级不影响传感器参数。

主要特点宽电压范围1.71V-3.6V1.8V兼容数字IO口低功耗模式下电源电流低至2µA±2G/±4G/±8G/±16G动态全量程范围 12bit有效数据(HR)I²C/SPI数字输出接口6D/4D方向检测自由落体检测单击双击检测及运动检测可编程中断生成电路内嵌自测试功能内嵌FIFO10000g高G抗击能力应用手机平板室内导航图像旋转运动激活用户接口游戏产品规格分类产品名称封装形式打印名称材料包装形式 SC7A20TR LGA-12-2x2x1.0 SC7A20 无铅编带内部框图XY ZC-to-V Converter Gain数符号测试条件最小值V CC电路不损坏-0.3 3.6V P电路不损坏V in电路不损坏T OPR电路不损坏T STG电路不损坏(VDD=2.5V, T测试条件123FS=0 (HR mode)FS=1 (HR mode)FS=2 (HR mode)FS=3 (HR mode)参数符号测试条件最小值典型值最大值单位零漂 Ty Off0 FS =0 --±40--mg温漂TC Off 与25°C 的最大偏差 -- ±0.5 -- mg/°C 自测输出V st1FS=0， X 轴 -- 276 -- LSb V st2 FS=0， Y 轴 -- 276 -- LSb V st3FS=0， Z 轴-- 984 -- LSb 系统带宽 BW -- ODR/2 -- HZ 工作温度T OPR-40--+85°C注意：电路2.5V 出厂校准。

bma250e使用手册

bma250e使用手册BMA250E是一款三轴加速度传感器，常用于物体运动检测、姿态识别和手势控制等应用。

以下是关于BMA250E使用手册的详细内容：1. 产品概述：BMA250E是一款数字式三轴加速度传感器，采用MEMS技术（微机电系统），具有高精度和低功耗的特点。

它能够测量物体在三个轴向上的加速度，并输出数字信号。

2. 产品特性：BMA250E具有以下主要特性：三轴加速度测量范围可配置，通常为±2g至±16g。

高分辨率和高精度的加速度测量。

内置温度传感器，可提供环境温度测量。

低功耗设计，适用于电池供电的应用。

支持I2C和SPI接口，方便与主控设备通信。

3. 硬件接口：BMA250E可以通过I2C或SPI接口与主控设备进行通信。

你需要根据你的应用选择合适的接口，并连接相应的引脚。

在连接时，请确保正确连接供电引脚、地引脚和数据引脚。

4. 寄存器配置：BMA250E内部有一系列寄存器，用于配置传感器的工作模式、测量范围和输出数据速率等参数。

你可以通过读写寄存器来配置传感器以满足你的应用需求。

具体的寄存器配置信息可以在BMA250E 的数据手册中找到。

5. 数据输出：BMA250E通过I2C或SPI接口将测量到的加速度数据传输给主控设备。

你可以根据需要选择合适的数据输出速率和分辨率。

传感器还可以输出温度数据，用于环境温度监测。

6. 功能示例：BMA250E可以应用于许多不同的应用场景，如运动检测、姿态识别和手势控制。

你可以根据具体需求配置传感器的工作模式和参数。

例如，你可以将传感器配置为在特定加速度阈值超过时触发中断，或者通过检测特定的手势来触发相应的操作。

7. 注意事项：在使用BMA250E时，请注意以下事项：确保正确连接传感器的供电引脚和地引脚，以及与主控设备的通信引脚。

仔细阅读BMA250E的数据手册，了解传感器的功能和寄存器配置。

根据你的应用需求，选择合适的加速度测量范围和输出数据速率。

完整版三轴数字加速度传感器ADXL345技术资料

概述：ADXL345是一款小而薄的超低功耗3轴加速度计，分辨率高（13位）,测量范围达±16g。

数字输出数据为16位二进制补码格式，可通过SPI（3线或4线）或I2C数字接口访问。

ADXL345非常适合移动设备应用。

它可以在倾斜检测应用中测量静态重力加速度，还可以测量运动或冲击导致的动态加速度。

其高分辨率（3.9mg/LSB），能够测量不到1.0。

的倾斜角度变化。

该器件提供多种特殊检测功能。

活动和非活动检测功能通过比较任意轴上的加速度与用户设置的阈值来检测有无运动发生。

敲击检测功能可以检测任意方向的单振和双振动作。

自由落体检测功能可以检测器件是否正在掉落。

这些功能可以独立映射到两个中断输岀引脚中的一个。

正在申请专利的集成式存储器管理系统采用一个32级先进先岀（FIFO）缓冲器，可用于存储数据，从而将主机处理器负荷降至最低，并降低整体系统功耗。

低功耗模式支持基于运动的智能电源管理，从而以极低的功耗进行阈值感测和运动加速度测量。

ADXL345采用3 mm X 5 mmx 1 mm，14引脚小型超薄塑料封装。

对比常用的飞思卡尔的MMZ7260三轴加速度传感器，ADXL345，具有测量精度高、可以通过SPI或I2C直接和单片机通讯等优点。

特性：超低功耗：VS= 2.5 V 时（典型值），测量模式下低至23uA，待机模式下为0.1 g A功耗随带宽自动按比例变化用户可选的分辨率10位固定分辨率全分辨率，分辨率随g范围提高而提高，±16g时高达13位（在所有g范围内保持4 mg/LSB的比例系数）正在申请专利的嵌入式存储器管理系统采用FIFO技术，可将主机处理器负荷降至最低。

单振/双振检测，活动/非活动监控，自由落体检测电源电压范围：2.0 V 至3.6 VI / O电压范围：1.7 V至VSSPI （3线和4线）和I2C数字接口灵活的中断模式，可映射到任一中断引脚通过串行命令可选测量范围通过串行命令可选带宽宽温度范围（-40°C至+85 °C）抗冲击能力：10,000 g无铅/符合RoHS标准小而薄：3 mn X 5 mm x 1 mm，LGA 封装模组尺寸：23*18*11mm （高度含插针高度应用：机器人控制、运动检测过程控制，电池供电系统硬盘驱动器（HDD）保护，单电源数据采集系统手机，医疗仪器，游戏和定点设备，工业仪器仪表，个人导航设备电路功能与优势ADXL345是一款小巧纤薄的低功耗三轴加速度计，可以对高达±6 g的加速度进行高分辨率（13位）测量。

三轴加速度传感器的z敏感轴的校准算法

三轴加速度传感器的z敏感轴的校准算法一、引言三轴加速度传感器是一种常用的传感器，广泛应用于物联网、智能家居、自动驾驶等领域。

在使用三轴加速度传感器时，需要对其进行校准，以保证其测量结果的准确性。

本文将介绍三轴加速度传感器z敏感轴的校准算法。

二、三轴加速度传感器的工作原理三轴加速度传感器是一种基于微机电系统（MEMS）技术的传感器。

它通过测量物体在三个方向上的加速度来确定物体的运动状态。

具体来说，当物体发生运动时，会产生惯性力，这个惯性力可以被转化为电信号输出。

因此，通过测量这些电信号，就可以确定物体在各个方向上的加速度。

三、z敏感轴的校准算法1. 原理由于三轴加速度传感器是一种基于微机电系统（MEMS）技术的传感器，因此其精度受到许多因素的影响。

其中一个主要因素是温度变化。

由于温度变化会导致材料膨胀或收缩，从而影响到MEMS芯片中的加速度传感器，因此需要进行校准。

在进行z敏感轴的校准时，需要将传感器放置在水平面上，并保持不动。

此时，z敏感轴应该与重力方向垂直。

因此，通过测量z敏感轴上的加速度值来确定传感器是否处于垂直状态。

如果传感器没有处于垂直状态，则需要进行校准。

2. 步骤（1）将传感器放置在水平面上，并保持不动。

（2）读取z敏感轴上的加速度值。

（3）如果加速度值不为0，则需要进行校准。

（4）将传感器旋转一定角度，并记录旋转角度和对应的加速度值。

（5）重复步骤4，直到旋转360度。

（6）计算出每个角度对应的期望加速度值。

（7）使用拟合算法计算出校准系数。

（8）使用校准系数对原始数据进行修正。

3. 拟合算法在步骤7中，需要使用拟合算法计算出校准系数。

常用的拟合算法有线性回归、多项式回归、指数回归等。

这里介绍一种基于最小二乘法的拟合算法。

最小二乘法是一种常用的拟合算法，它通过最小化残差平方和来确定拟合函数的系数。

在z敏感轴的校准中，可以使用最小二乘法来确定校准系数。

假设有n个数据点，每个数据点的坐标为(xi,yi)，其中xi表示旋转角度，yi表示对应的加速度值。

三轴加速度传感器使用说明

三轴加速度传感器模块使用说明概述H48C三轴加速度传感器能测量在三个轴（X、Y、Z）方向上的±3g的加速度值，模块板载一个自动负载调节器，为H48C提供3.3V的电源，H48C输出的模拟信号（电压）由模块上的MCP3204（四通道，12-bit）读取并转换为数字信号输出。

特点●测量范围±3g（每个轴）●使用MEMS (微型机电系统) 技术，实现自动补偿●板载自动负载调节器，和高解析度的ADC●体积小巧：0.7" x 0.8" (17.8 mm x 20.3 mm)●工作温度范围广-25° to 75° C基本连线图H48C连接到C51上只需要直接选择任意三个脚连接连接即可，如图1图 1* 与单片机连接的引脚可以任意选择工作原理通过MEMS技术，和内置的补偿H48C加速度传感器通过MCP3204模数转换器实现同步输出，要获取指定轴加速度的值，实际上是读取指定轴的电压在通过下面的公式计算出加速度的值，公式如下：G = ((axis – vRef) / 4095) x (3.3 / 0.3663)在这个公式中axis和vRef表示通过AD转化得到的计数值，4095是一个12-bitADC的最大计数输出，3.3是H48C提供给内部的电压，0.3663是加速度1g的时候H48C输出的电压。

我们可以把公式简化成如下表达式。

G = (axis – vRef) x 0.0022引脚的定义以及说明（1）CLK 同步时钟输入（2）DIO 双向数据/从主机通信（3）Vss 电源地（0V）（4）Zero-G “自由落体”输出，高电平有效（5）CS\ 片选信号，低电平有效（6）Vdd 电源+5v标号说明最小典型最大单位V DD工作电压 4.5 5.0 5.5 V V SS地连接0 VI DD工作电流7 10 MaV IH高电压输入0.7 V DD V V IL低电压输入0.3 V DD V V OH高电压输出 4.1 V V OL低电压输出0.4 V采样率200 Sps ADC（MCP3204）分辨率12 Bit测量范围-3 +3 g敏感度366.3 mV/g精度10 %非线性度-2 +2 %工作温度范围-25 75 ℃Zero-G输出高电平 3.2 3.3 VZero-G输出延时 1 ms 确定H48C的X、Y、Z 轴如下图关于MCP3204Microchip 的MCP3204/3208 器件是具有片上采样和保持电路的12 位逐次逼近型模数（Analog-to-Digital，D）转换器。

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我们可以把公式简化成如下表达式。

MCP3204可被编程为提供2组伪差分输入对或4个单端输入。

MCP3208可被编程为提供4组差分输入对或8 个单端输入。

它使用与SPI 协议兼容的简单串行端口与器件通信。

器件的转换速率可高达100 ksps。

MCP3204/3208器件具有2.7V 至5.5V 的宽电压工作范围。

功能框图如下：图 2通过标准的SPI兼容串行接口实现与MCP3204/3208的通信。

将CS 线拉为低电平可以启动与器件之间的通信。

如果在引脚CS 为低电平时给器件上电，则首先必须将此引脚拉高，然后再拉低才能启动通信。

在CS 为低电平且D 为高电平时接收到的第一个时钟IN 构成启动位。

启动位后跟的SGL/DIFF 位用于确定使用单端还是差分输入模式进行转换。

之后的三位（D0、D1和D2）用于选择输入通道配置。

相关内容具体见MCP3204的数据手册。

控制位选择如图3。

由于C51没有SPI串口，这里需要使用C51的i/o通过软件模拟方式来实现SPI通信。

与MCP3204通信的SPI时序图如图4 。

控制位选择图 3MCP3204与C51通信时序参考图图4DEMO程序说明SPI是一种简单的串行通信协议很容易用软件方式模拟。

软件模拟用SPI 0，0方式与MCP3204通信。

CS信号为片选信号，低电平有效，所以在实现SPI通信时应该先拉低CS 信号，通信结束后再拉高CS信号，终止SPI通信。

下图为发送1bit的时序图（最高位优先）。

可以看到，我们首先通过数据口发送一个BIT 位，然后时钟口才发送出一个脉冲。

在下一个时钟脉冲发送之前，发送完一位数据。

图 5发送数据程序如下：void SEND_1(void){SPI_IO=1;SPI_CLK=1;_nop_();_nop_();SPI_CLK=0;_nop_();_nop_();_nop_();_nop_();}上述程序发送一位数据1，发送数据0的程序与其类似。

这样我们就可以利用模拟的SPI跟MCP3204发送命令了。

由于向MCP3204发送命令，以及从MCP3204接收数据，并不是同时发生，所以这里使用一个I/O口实现了数据的发送与接收。

下图为1-bit数据接收到时序图。

图 6这里采用的是POST模式，即接收数据应该在两个脉冲之间进行。

接收数据程序如下：unsigned int read_spi(void){unsigned int read_verh = 0;unsigned int read_verl = 0;unsigned char count ;for(count=0; count<5; count++){read_verh = (read_verh << 1); //读取高5位SPI_CLK = 0;_nop_();_nop_();_nop_();_nop_();SPI_CLK = 1;_nop_();_nop_();_nop_();SPI_CLK = 0; //形成一个脉冲_nop_();if(SPI_IO == 1)read_verh |= 0x01;elseread_verl &= 0xfe; //接收一个数据}for(count=0; count<8; count++){read_verl = (read_verl << 1);//读取低8位SPI_CLK = 0;_nop_();_nop_();_nop_();_nop_();SPI_CLK = 1;_nop_();_nop_();_nop_();_nop_();SPI_CLK = 0;_nop_();if(SPI_IO == 1)read_verl |= 0x01;elseread_verl &= 0xfe;}return ((read_verh<<8)|read_verl);}MCP3204发出来的数据共有13位最高位是空位0，为了保证读入数据不丢失，根据MCP3204与单片机通信的时序图，这里将13位数据分成高5位和地8位，分别接受，两个接收中间要保持时钟信号为低。

向MCP3204发送启动命令：void start_operation(void){SEND_1(); //启动位SEND_1(); //SGL/DIFF位单端模式}向MCP3204发送通道选择命令：根据图3 发送相应的数据即可，下面是通道0的命令，SEND_1();SEND_0();SEND_0();SPI_IO=1;注意这里如果SPI_IO 为低，需要将其拉高，负责MCP3204无法识别发进来的命令。

完整程序见DEMO。

在发送启动位、模式选择位和通道选择位以后，就启动了H48C，接下来就可以调用上面的接收程序读取数据了。

接下来就可以根据读取的每个通道的计数值计算相应轴的加速度值了。

实现程序如下：/*--------------------------------------------------------------------------------------------------函数名称：Get_H48C函数功能：分别读取X、Y、Z和基准电压VREF的计数值--------------------------------------------------------------------------------------------------*/void Get_H48C(unsigned char ch){SPI_CS = 0;start_operation();//发送启动SPI_CLK = 0; //拉低等待mcpch(3);//发生编码delay_nus(40);//等待转化完毕vref = read_spi(); //测量基准电压SPI_CS = 1;delay_nms(2);SPI_CS = 0; //开始测量X,Y,Zstart_operation();//发送启动SPI_CLK = 0;mcpch(ch);//发生编码delay_nus(40);axis = read_spi(); //测量基准电压SPI_CS = 1;}注意，由于基准电压会发生变化，这里每测量一个轴的计数值，都要测量一次基准电压值，以保持每次测量的准确性。

/*--------------------------------------------------------------------------------------------------函数名称：Get_xyzacc函数功能：分别计算X、Y、Z的加速度说明：G = ((axis –vRef) / 4095) x (3.3 / 0.3663即G = (axis – vRef) x 0.0022--------------------------------------------------------------------------------------------------*/void Get_xyzacc(void){unsigned char axisnum;for(axisnum=0; axisnum<3; axisnum++){Get_H48C(axisnum);if(axisnum == 0){if(axis >= vref)XgForce = (axis - vref)*0.0022 ;elseXgForce = (vref - axis)*0.0022 ;}if(axisnum == 1){if(axis >= vref)YgForce = (axis - vref)*0.0022;elseYgForce = (vref - axis)*0.0022;}if(axisnum == 2){if(axis >= vref)ZgForce = (axis - vref)*0.0022;elseZgForce = (vref - axis)*0.0022;}}}同时如果在静止的情况下，我们还可以根据计算出来的相应轴的加速度值来计算倾斜角度。