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33 lines
1.1 KiB
Markdown
33 lines
1.1 KiB
Markdown
# About
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Test application for the HMC5883L 3-axis digital compass
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# Usage
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The test application demonstrates the use of the HMC5883L. It uses the
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default configuration parameters.
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- Continuous measurement at a Data Output Rate (DOR) of 15 Hz
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- Normal mode, no biasing
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- Gain 1090 LSB/Gs
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- No averaging of data samples
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The application can use different approaches to get new data:
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- using the #hmc5883l_read function at a lower rate than the the DOR
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- using the data-ready interrupt (**DRDY**), see #hmc5883l_init_int.
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To use the data-ready interrupt (**DRDY**), the application has to enable
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module `hmc5883l_int` and has to configure the GPIO to which the
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interrupt signal is connected. This is done by overrding the default
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configuration parameter `HMC5883L_PARAM_INT_PIN` if necessary, for example:
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```
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USEMODULE=hmc5883l_int CFLAGS='-DHMC5883L_PARAM_INT_PIN=GPIO_PIN\(0,12\)' \
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make flash -C tests/drivers/hmc5883l BOARD=...
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```
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The heading angle is calculated for a magnetic declination in radians defined
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by `HMC5883L_MAG_DECL`. This depends on the current location. The value for
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the current location can be determined at http://www.magnetic-declination.com/.
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