Chen Wei Ting
zero torque and encoder
Diff: LSM9DS1.cpp
- Revision:
- 0:c23e915f255b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/LSM9DS1.cpp Sun Aug 05 13:15:56 2018 +0000
@@ -0,0 +1,401 @@
+#include "LSM9DS1.h"
+
+LSM9DS1::LSM9DS1(PinName sda, PinName scl, uint8_t xgAddr, uint8_t mAddr) : i2c(sda, scl)
+{
+ // xgAddress and mAddress will store the 7-bit I2C address, if using I2C.
+ xgAddress = xgAddr;
+ mAddress = mAddr;
+}
+
+uint16_t LSM9DS1::begin(gyro_scale gScl, accel_scale aScl, mag_scale mScl,
+ gyro_odr gODR, accel_odr aODR, mag_odr mODR)
+{
+ // Store the given scales in class variables. These scale variables
+ // are used throughout to calculate the actual g's, DPS,and Gs's.
+ gScale = gScl;
+ aScale = aScl;
+ mScale = mScl;
+
+ // Once we have the scale values, we can calculate the resolution
+ // of each sensor. That's what these functions are for. One for each sensor
+ calcgRes(); // Calculate DPS / ADC tick, stored in gRes variable
+ calcmRes(); // Calculate Gs / ADC tick, stored in mRes variable
+ calcaRes(); // Calculate g / ADC tick, stored in aRes variable
+
+
+ // To verify communication, we can read from the WHO_AM_I register of
+ // each device. Store those in a variable so we can return them.
+ // The start of the addresses we want to read from
+ char cmd[2] = {
+ WHO_AM_I_XG,
+ 0
+ };
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(xgAddress, cmd+1, 1);
+ uint8_t xgTest = cmd[1]; // Read the accel/gyro WHO_AM_I
+
+ // Reset to the address of the mag who am i
+ cmd[1] = WHO_AM_I_M;
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(mAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(mAddress, cmd+1, 1);
+ uint8_t mTest = cmd[1]; // Read the mag WHO_AM_I
+
+ // Gyro initialization stuff:
+ initGyro(); // This will "turn on" the gyro. Setting up interrupts, etc.
+ setGyroODR(gODR); // Set the gyro output data rate and bandwidth.
+ setGyroScale(gScale); // Set the gyro range
+
+ // Accelerometer initialization stuff:
+ initAccel(); // "Turn on" all axes of the accel. Set up interrupts, etc.
+ setAccelODR(aODR); // Set the accel data rate.
+ setAccelScale(aScale); // Set the accel range.
+
+ // Magnetometer initialization stuff:
+ initMag(); // "Turn on" all axes of the mag. Set up interrupts, etc.
+ setMagODR(mODR); // Set the magnetometer output data rate.
+ setMagScale(mScale); // Set the magnetometer's range.
+
+ // Once everything is initialized, return the WHO_AM_I registers we read:
+ return (xgTest << 8) | mTest;
+}
+
+void LSM9DS1::initGyro()
+{
+ char cmd[4] = {
+ CTRL_REG1_G,
+ gScale | G_ODR_119_BW_14,
+ 0, // Default data out and int out
+ 0 // Default power mode and high pass settings
+ };
+
+ // Write the data to the gyro control registers
+ i2c.write(xgAddress, cmd, 4);
+}
+
+void LSM9DS1::initAccel()
+{
+ char cmd[4] = {
+ CTRL_REG5_XL,
+ 0x38, // Enable all axis and don't decimate data in out Registers
+ (A_ODR_119 << 5) | (aScale << 3) | (A_BW_AUTO_SCALE), // 119 Hz ODR, set scale, and auto BW
+ 0 // Default resolution mode and filtering settings
+ };
+
+ // Write the data to the accel control registers
+ i2c.write(xgAddress, cmd, 4);
+}
+
+void LSM9DS1::initMag()
+{
+ char cmd[4] = {
+ CTRL_REG1_M,
+ 0x10, // Default data rate, xy axes mode, and temp comp
+ mScale << 5, // Set mag scale
+ 0 // Enable I2C, write only SPI, not LP mode, Continuous conversion mode
+ };
+
+ // Write the data to the mag control registers
+ i2c.write(mAddress, cmd, 4);
+}
+
+void LSM9DS1::readAccel()
+{
+ // The data we are going to read from the accel
+ char data[6];
+
+ // The start of the addresses we want to read from
+ char subAddress = OUT_X_L_XL;
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, &subAddress, 1, true);
+ // Read in all 8 bit registers containing the axes data
+ i2c.read(xgAddress, data, 6);
+
+ // Reassemble the data and convert to g
+ ax_raw = data[0] | (data[1] << 8);
+ ay_raw = data[2] | (data[3] << 8);
+ az_raw = data[4] | (data[5] << 8);
+ ax = ax_raw * aRes;
+ ay = ay_raw * aRes;
+ az = az_raw * aRes;
+}
+
+void LSM9DS1::readMag()
+{
+ // The data we are going to read from the mag
+ char data[6];
+
+ // The start of the addresses we want to read from
+ char subAddress = OUT_X_L_M;
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(mAddress, &subAddress, 1, true);
+ // Read in all 8 bit registers containing the axes data
+ i2c.read(mAddress, data, 6);
+
+ // Reassemble the data and convert to degrees
+ mx_raw = data[0] | (data[1] << 8);
+ my_raw = data[2] | (data[3] << 8);
+ mz_raw = data[4] | (data[5] << 8);
+ mx = mx_raw * mRes;
+ my = my_raw * mRes;
+ mz = mz_raw * mRes;
+}
+
+void LSM9DS1::readTemp()
+{
+ // The data we are going to read from the temp
+ char data[2];
+
+ // The start of the addresses we want to read from
+ char subAddress = OUT_TEMP_L;
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, &subAddress, 1, true);
+ // Read in all 8 bit registers containing the axes data
+ i2c.read(xgAddress, data, 2);
+
+ // Temperature is a 12-bit signed integer
+ temperature_raw = data[0] | (data[1] << 8);
+
+ temperature_c = (float)temperature_raw / 8.0 + 25;
+ temperature_f = temperature_c * 1.8 + 32;
+}
+
+
+void LSM9DS1::readGyro()
+{
+ // The data we are going to read from the gyro
+ char data[6];
+
+ // The start of the addresses we want to read from
+ char subAddress = OUT_X_L_G;
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, &subAddress, 1, true);
+ // Read in all 8 bit registers containing the axes data
+ i2c.read(xgAddress, data, 6);
+
+ // Reassemble the data and convert to degrees/sec
+ gx_raw = data[0] | (data[1] << 8);
+ gy_raw = data[2] | (data[3] << 8);
+ gz_raw = data[4] | (data[5] << 8);
+ gx = gx_raw * gRes;
+ gy = gy_raw * gRes;
+ gz = gz_raw * gRes;
+}
+
+void LSM9DS1::setGyroScale(gyro_scale gScl)
+{
+ // The start of the addresses we want to read from
+ char cmd[2] = {
+ CTRL_REG1_G,
+ 0
+ };
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(xgAddress, cmd+1, 1);
+
+ // Then mask out the gyro scale bits:
+ cmd[1] &= 0xFF^(0x3 << 3);
+ // Then shift in our new scale bits:
+ cmd[1] |= gScl << 3;
+
+ // Write the gyroscale out to the gyro
+ i2c.write(xgAddress, cmd, 2);
+
+ // We've updated the sensor, but we also need to update our class variables
+ // First update gScale:
+ gScale = gScl;
+ // Then calculate a new gRes, which relies on gScale being set correctly:
+ calcgRes();
+}
+
+void LSM9DS1::setAccelScale(accel_scale aScl)
+{
+ // The start of the addresses we want to read from
+ char cmd[2] = {
+ CTRL_REG6_XL,
+ 0
+ };
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(xgAddress, cmd+1, 1);
+
+ // Then mask out the accel scale bits:
+ cmd[1] &= 0xFF^(0x3 << 3);
+ // Then shift in our new scale bits:
+ cmd[1] |= aScl << 3;
+
+ // Write the accelscale out to the accel
+ i2c.write(xgAddress, cmd, 2);
+
+ // We've updated the sensor, but we also need to update our class variables
+ // First update aScale:
+ aScale = aScl;
+ // Then calculate a new aRes, which relies on aScale being set correctly:
+ calcaRes();
+}
+
+void LSM9DS1::setMagScale(mag_scale mScl)
+{
+ // The start of the addresses we want to read from
+ char cmd[2] = {
+ CTRL_REG2_M,
+ 0
+ };
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(mAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(mAddress, cmd+1, 1);
+
+ // Then mask out the mag scale bits:
+ cmd[1] &= 0xFF^(0x3 << 5);
+ // Then shift in our new scale bits:
+ cmd[1] |= mScl << 5;
+
+ // Write the magscale out to the mag
+ i2c.write(mAddress, cmd, 2);
+
+ // We've updated the sensor, but we also need to update our class variables
+ // First update mScale:
+ mScale = mScl;
+ // Then calculate a new mRes, which relies on mScale being set correctly:
+ calcmRes();
+}
+
+void LSM9DS1::setGyroODR(gyro_odr gRate)
+{
+ // The start of the addresses we want to read from
+ char cmd[2] = {
+ CTRL_REG1_G,
+ 0
+ };
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(xgAddress, cmd+1, 1);
+
+ // Then mask out the gyro odr bits:
+ cmd[1] &= (0x3 << 3);
+ // Then shift in our new odr bits:
+ cmd[1] |= gRate;
+
+ // Write the gyroodr out to the gyro
+ i2c.write(xgAddress, cmd, 2);
+}
+
+void LSM9DS1::setAccelODR(accel_odr aRate)
+{
+ // The start of the addresses we want to read from
+ char cmd[2] = {
+ CTRL_REG6_XL,
+ 0
+ };
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(xgAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(xgAddress, cmd+1, 1);
+
+ // Then mask out the accel odr bits:
+ cmd[1] &= 0xFF^(0x7 << 5);
+ // Then shift in our new odr bits:
+ cmd[1] |= aRate << 5;
+
+ // Write the accelodr out to the accel
+ i2c.write(xgAddress, cmd, 2);
+}
+
+void LSM9DS1::setMagODR(mag_odr mRate)
+{
+ // The start of the addresses we want to read from
+ char cmd[2] = {
+ CTRL_REG1_M,
+ 0
+ };
+
+ // Write the address we are going to read from and don't end the transaction
+ i2c.write(mAddress, cmd, 1, true);
+ // Read in all the 8 bits of data
+ i2c.read(mAddress, cmd+1, 1);
+
+ // Then mask out the mag odr bits:
+ cmd[1] &= 0xFF^(0x7 << 2);
+ // Then shift in our new odr bits:
+ cmd[1] |= mRate << 2;
+
+ // Write the magodr out to the mag
+ i2c.write(mAddress, cmd, 2);
+}
+
+void LSM9DS1::calcgRes()
+{
+ // Possible gyro scales (and their register bit settings) are:
+ // 245 DPS (00), 500 DPS (01), 2000 DPS (10).
+ switch (gScale)
+ {
+ case G_SCALE_245DPS:
+ gRes = 245.0 / 32768.0;
+ break;
+ case G_SCALE_500DPS:
+ gRes = 500.0 / 32768.0;
+ break;
+ case G_SCALE_2000DPS:
+ gRes = 2000.0 / 32768.0;
+ break;
+ }
+}
+
+void LSM9DS1::calcaRes()
+{
+ // Possible accelerometer scales (and their register bit settings) are:
+ // 2 g (000), 4g (001), 6g (010) 8g (011), 16g (100).
+ switch (aScale)
+ {
+ case A_SCALE_2G:
+ aRes = 2.0 / 32768.0;
+ break;
+ case A_SCALE_4G:
+ aRes = 4.0 / 32768.0;
+ break;
+ case A_SCALE_8G:
+ aRes = 8.0 / 32768.0;
+ break;
+ case A_SCALE_16G:
+ aRes = 16.0 / 32768.0;
+ break;
+ }
+}
+
+void LSM9DS1::calcmRes()
+{
+ // Possible magnetometer scales (and their register bit settings) are:
+ // 2 Gs (00), 4 Gs (01), 8 Gs (10) 12 Gs (11).
+ switch (mScale)
+ {
+ case M_SCALE_4GS:
+ mRes = 4.0 / 32768.0;
+ break;
+ case M_SCALE_8GS:
+ mRes = 8.0 / 32768.0;
+ break;
+ case M_SCALE_12GS:
+ mRes = 12.0 / 32768.0;
+ break;
+ case M_SCALE_16GS:
+ mRes = 16.0 / 32768.0;
+ break;
+ }
+}
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