Arduino library to support the ISM330DHCX 3D accelerometer and 3D gyroscope
This sensor uses I2C or SPI to communicate. For I2C it is then required to create a TwoWire interface before accessing to the sensors:
TwoWire dev_i2c(I2C_SDA, I2C_SCL);
dev_i2c.begin();
For SPI it is then required to create a SPI interface before accessing to the sensors:
SPIClass dev_spi(SPI_MOSI, SPI_MISO, SPI_SCK);
dev_spi.begin();
An instance can be created and enabled when the I2C bus is used following the procedure below:
ISM330DHCXSensor AccGyr(&dev_i2c);
AccGyr.begin();
AccGyr.ACC_Enable();
AccGyr.GYRO_Enable();
An instance can be created and enabled when the SPI bus is used following the procedure below:
ISM330DHCXSensor AccGyr(&dev_spi, CS_PIN);
AccGyr.begin();
AccGyr.ACC_Enable();
AccGyr.GYRO_Enable();
The access to the sensor value is done as explained below:
Read accelerometer and gyroscope.
int32_t accelerometer[3];
int32_t gyroscope[3];
AccGyr.ACC_GetAxes(accelerometer);
AccGyr.GYRO_GetAxes(gyroscope);
All the MEMS drivers in stm32duino repositories have the same units when returning physical (scaled) values:
- mg for accelerometer (thousandth of g, 1g is 9.81 m/s^2)
- mdps for gyroscope (thousandth of degree/s)
- mgauss for magnetometer (thousandth of gauss)
Readings can be obtained either as raw (unscaled) uint16_t values from the XXX_GetAxesRaw functions, or as physical (scaled) uint32_t values from the XXX_GetAxes functions, where XXX is either ACC or GYRO. The factor to use for scaling from a raw to a physical value is obtained from the XXX_GetSensitivity functions.
For example, to convert the raw acceleration reading to float m/s^2, the following can be done:
int16_t acc_raw[3];
float acc_ms2[3];
float acc_sensitivity;
AccGyr.ACC_GetAxesRaw(acc_raw);
AccGyr.ACC_GetSensitivity(&acc_sensitivity);
acc_ms2[0] = ((float)acc_raw[0] * acc_sensitivity) / 1000.0f * 9.81f;
acc_ms2[1] = ((float)acc_raw[1] * acc_sensitivity) / 1000.0f * 9.81f;
acc_ms2[2] = ((float)acc_raw[2] * acc_sensitivity) / 1000.0f * 9.81f;You can find the source files at
https://github.com/stm32duino/ISM330DHCX
The ISM330DHCX datasheet is available at
https://www.st.com/en/mems-and-sensors/ism330dhcx.html