39 lines
1.9 KiB
Plaintext
39 lines
1.9 KiB
Plaintext
= Attaching a LIS3DH Nano Accelerometer via i2c.
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This example shows you how to interface the Raspberry Pi Pico to the LIS3DH accelerometer and temperature sensor.
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The code reads and displays the acceleration values of the board in the 3 axes and the ambient temperature value. The datasheet for the sensor can be found at https://www.st.com/resource/en/datasheet/cd00274221.pdf. The device is being operated on 'normal mode' and at a frequency of 1.344 kHz (this can be changed by editing the ODR bits of CTRL_REG4). The range of the data is controlled by the FS bit in CTRL_REG4 and is equal to ±2g in this example. The sensitivity depends on the operating mode and data range; exact values can be found on page 10 of the datasheet. In this case, the sensitivity value is 4mg (where g is the value of gravitational acceleration on the surface of Earth). In order to use the auxiliary ADC to read temperature, the we must set the BDU bit to 1 in CTRL_REG4 and the ADC_EN bit to 1 in TEMP_CFG_REG. Temperature is communicated through ADC 3.
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[NOTE]
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=====
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The sensor doesn't have features to eliminate offsets in the data and these will need to be taken into account in the code.
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=====
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== Wiring information
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Wiring up the device requires 4 jumpers, to connect VIN, GND, SDA and SCL. The example here uses I2C port 0, which is assigned to GPIO 4 (SDA) and 5 (SCL) in software. Power is supplied from the 3V pin.
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[[lis3dh_i2c_wiring]]
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[pdfwidth=75%]
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.Wiring Diagram for LIS3DH.
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image::lis3dh_i2c.png[]
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== List of Files
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CMakeLists.txt:: CMake file to incorporate the example in to the examples build tree.
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lis3dh_i2c.c:: The example code.
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== Bill of Materials
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.A list of materials required for the example
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[[lis3dh-bom-table]]
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[cols=3]
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|===
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| *Item* | *Quantity* | Details
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| Breadboard | 1 | generic part
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| Raspberry Pi Pico | 1 | https://www.raspberrypi.com/products/raspberry-pi-pico/
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| LIS3DH board| 1 | https://www.adafruit.com/product/2809
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| M/M Jumper wires | 4 | generic part
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|===
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