Support Sparkfun ICM20948 Breakout board (SPI only, I2C TBD)

src/ahr/AhrGizmoImu.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "ahr.h"
+
+class AhrGizmoImu : public AhrGizmo {
+private:
+  AhrConfig *config;
+  AhrState *state;
+
+  //NED reference frame
+  //gyro in rad/sec
+  //acc in g
+  //mag any unit of measurement
+
+  // quaternion of sensor frame relative to auxiliary frame
+  float q0 = 1.0f; //Initialize quaternion
+  float q1 = 0.0f;
+  float q2 = 0.0f;
+  float q3 = 0.0f;
+
+  public:
+  AhrGizmoImu(Ahr *ahr) {
+    this->config = &(ahr->config);
+    this->state = (AhrState*)ahr;
+  }
+
+  void setInitalOrientation(float *qnew) {
+    q0 = qnew[0];
+    q1 = qnew[1];
+    q2 = qnew[2];
+    q3 = qnew[3];
+  }
+
+  bool update() {
+    // nothing to do - the imu update already updated state->q quaternions
+    return true;
+  }
+};

src/ahr/ahr.cpp

@@ -149,7 +149,7 @@ void Ahr::getQFromMag(float *q) {
     q[3] = 0;
     Serial.println("AHR: No Magnetometer, yaw:0.00");
   }else{
-    float yaw_rad = -atan2(my, mx);
+    float yaw_rad = atan2(my, mx);
     yaw = yaw_rad * rad_to_deg;
     pitch = 0;
     roll = 0;

src/cfg/cfg.h

@@ -203,7 +203,7 @@ SOFTWARE.
   MF_PARAM( gps_baud,          0, int32_t, 'i') \
 \
   /*IMU - Inertial Measurement Unit (acc/gyro)*/ \
-  MF_PARAM( imu_gizmo,         0, int32_t, 'e', mf_NONE,mf_BMI270,mf_MPU6000,mf_MPU6050,mf_MPU6500,mf_MPU9150,mf_MPU9250,mf_ICM45686,mf_ICM42688) \
+  MF_PARAM( imu_gizmo,         0, int32_t, 'e', mf_NONE,mf_BMI270,mf_MPU6000,mf_MPU6050,mf_MPU6500,mf_MPU9150,mf_MPU9250,mf_ICM45686,mf_ICM42688,mf_ICM20948) \
   MF_PARAM( imu_spi_bus,      -1, int32_t, 'i') \
   MF_PARAM( imu_i2c_bus,      -1, int32_t, 'i') \
   MF_PARAM( imu_i2c_adr,       0, int32_t, 'i') \

src/imu/ICM20948/AK09916_ENUMERATIONS.h

@@ -0,0 +1,15 @@
+#ifndef _AK09916_ENUMERATIONS_H_
+#define _AK09916_ENUMERATIONS_H_
+
+typedef enum
+{
+  AK09916_mode_power_down = 0x00,
+  AK09916_mode_single = (0x01 << 0),
+  AK09916_mode_cont_10hz = (0x01 << 1),
+  AK09916_mode_cont_20hz = (0x02 << 1),
+  AK09916_mode_cont_50hz = (0x03 << 1),
+  AK09916_mode_cont_100hz = (0x04 << 1),
+  AK09916_mode_self_test = (0x01 << 4),
+} AK09916_mode_e;
+
+#endif // _AK09916_ENUMERATIONS_H_

src/imu/ICM20948/AK09916_REGISTERS.h

@@ -0,0 +1,83 @@
+#ifndef _AK09916_REGISTERS_H_
+#define _AK09916_REGISTERS_H_
+
+#include <stdint.h>
+
+typedef enum
+{
+  AK09916_REG_WIA1 = 0x00,
+  AK09916_REG_WIA2,
+  AK09916_REG_RSV1,
+  AK09916_REG_RSV2, // Reserved register. We start reading here when using the DMP. Secret sauce...
+  // discontinuity - containing another nine reserved registers? Secret sauce...
+  AK09916_REG_ST1 = 0x10,
+  AK09916_REG_HXL,
+  AK09916_REG_HXH,
+  AK09916_REG_HYL,
+  AK09916_REG_HYH,
+  AK09916_REG_HZL,
+  AK09916_REG_HZH,
+  // discontinuity
+  AK09916_REG_ST2 = 0x18,
+  // discontinuity
+  AK09916_REG_CNTL2 = 0x31,
+  AK09916_REG_CNTL3,
+} AK09916_Reg_Addr_e;
+
+typedef struct
+{
+  uint8_t WIA1;
+} AK09916_WIA1_Reg_t;
+
+typedef struct
+{
+  uint8_t WIA2;
+} AK09916_WIA2_Reg_t;
+
+typedef struct
+{
+  uint8_t DRDY : 1;
+  uint8_t DOR : 1;
+  uint8_t reserved_0 : 6;
+} AK09916_ST1_Reg_t;
+
+// typedef struct{
+
+// }AK09916_HXL_Reg_t;
+
+// typedef struct{
+
+// }AK09916_HXH_Reg_t;
+// typedef struct{
+
+// }AK09916_HYL_Reg_t;
+// typedef struct{
+
+// }AK09916_HYH_Reg_t;
+// typedef struct{
+
+// }AK09916_HZL_Reg_t;
+// typedef struct{
+
+// }AK09916_HZH_Reg_t;
+
+typedef struct
+{
+  uint8_t reserved_0 : 3;
+  uint8_t HOFL : 1;
+  uint8_t reserved_1 : 4;
+} AK09916_ST2_Reg_t;
+
+typedef struct
+{
+  uint8_t MODE : 5;
+  uint8_t reserved_0 : 3;
+} AK09916_CNTL2_Reg_t;
+
+typedef struct
+{
+  uint8_t SRST : 1;
+  uint8_t reserved_0 : 7;
+} AK09916_CNTL3_Reg_t;
+
+#endif // _AK09916_REGISTERS_H_