Remove mpu6050_scale from core_t by providing a sensor independent way

of determining a revision code.  Previously there was mpu6050 specific
code in cli.c (the status command).

Finally this commit has removed all non-serial port configuration
settings from core_t so that a future commit can refactor core_t to
reduce dependencies on serial port code.

In doing this I also noted from other source code that the MPU6050
accelerometer trim for some revisions appeared to be incorrectly set to
255 * 8 instead of 256 * 8.

src/config.c

@@ -10,6 +10,7 @@
 #include "drivers/system_common.h"
 
 #include "statusindicator.h"
+#include "sensors_common.h"
 #include "sensors_acceleration.h"
 #include "telemetry_common.h"
 #include "gps_common.h"

src/drivers/accgyro_mpu6050.c

@@ -132,9 +132,14 @@ static void mpu6050AccRead(int16_t *accData);
 static void mpu6050GyroInit(sensor_align_e align);
 static void mpu6050GyroRead(int16_t *gyroData);
 
-static uint8_t mpuAccelHalf = 0;
+typedef enum {
+    MPU_6050_HALF_RESOLUTION,
+    MPU_6050_FULL_RESOLUTION
+} mpu6050Resolution_e;
 
-bool mpu6050Detect(sensor_t *acc, sensor_t *gyro, uint16_t lpf, uint8_t *scale)
+static mpu6050Resolution_e mpuAccelTrim;
+
+bool mpu6050Detect(sensor_t *acc, sensor_t *gyro, uint16_t lpf)
 {
     bool ack;
     uint8_t sig, rev;
@@ -150,18 +155,22 @@ bool mpu6050Detect(sensor_t *acc, sensor_t *gyro, uint16_t lpf, uint8_t *scale)
     // The contents of WHO_AM_I are the upper 6 bits of the MPU-60X0’s 7-bit I2C address.
     // The least significant bit of the MPU-60X0’s I2C address is determined by the value of the AD0 pin. (we know that already).
     // But here's the best part: The value of the AD0 pin is not reflected in this register.
+
     if (sig != (MPU6050_ADDRESS & 0x7e))
         return false;
 
+    // There is a map of revision contained in the android source tree which is quite comprehensive and may help to understand this code
+    // See https://android.googlesource.com/kernel/msm.git/+/eaf36994a3992b8f918c18e4f7411e8b2320a35f/drivers/misc/mpu6050/mldl_cfg.c
+
     // determine product ID and accel revision
     i2cRead(MPU6050_ADDRESS, MPU_RA_XA_OFFS_H, 6, tmp);
     rev = ((tmp[5] & 0x01) << 2) | ((tmp[3] & 0x01) << 1) | (tmp[1] & 0x01);
     if (rev) {
         /* Congrats, these parts are better. */
         if (rev == 1) {
-            mpuAccelHalf = 1;
+            mpuAccelTrim = MPU_6050_HALF_RESOLUTION;
         } else if (rev == 2) {
-            mpuAccelHalf = 0;
+            mpuAccelTrim = MPU_6050_FULL_RESOLUTION;
         } else {
             failureMode(5);
         }
@@ -171,24 +180,21 @@ bool mpu6050Detect(sensor_t *acc, sensor_t *gyro, uint16_t lpf, uint8_t *scale)
         if (!rev) {
             failureMode(5);
         } else if (rev == 4) {
-            mpuAccelHalf = 1;
+            mpuAccelTrim = MPU_6050_HALF_RESOLUTION;
         } else {
-            mpuAccelHalf = 0;
+            mpuAccelTrim = MPU_6050_FULL_RESOLUTION;
         }
     }
 
     acc->init = mpu6050AccInit;
     acc->read = mpu6050AccRead;
+    acc->revisionCode = (mpuAccelTrim == MPU_6050_HALF_RESOLUTION  ? 'o' : 'n'); // es/non-es variance between MPU6050 sensors, half my boards are mpu6000ES.
     gyro->init = mpu6050GyroInit;
     gyro->read = mpu6050GyroRead;
 
     // 16.4 dps/lsb scalefactor
     gyro->scale = (4.0f / 16.4f) * (M_PI / 180.0f) * 0.000001f;
 
-    // give halfacc (old revision) back to system
-    if (scale)
-        *scale = mpuAccelHalf;
-
     // default lpf is 42Hz
     switch (lpf) {
         case 256:
@@ -220,10 +226,14 @@ bool mpu6050Detect(sensor_t *acc, sensor_t *gyro, uint16_t lpf, uint8_t *scale)
 
 static void mpu6050AccInit(sensor_align_e align)
 {
-    if (mpuAccelHalf)
+    switch(mpuAccelTrim) {
-        acc_1G = 255 * 8;
+        case MPU_6050_HALF_RESOLUTION:
-    else
+            acc_1G = 256 * 8;
+            break;
+        case MPU_6050_FULL_RESOLUTION:
             acc_1G = 512 * 8;
+            break;
+    }
 
     if (align > 0)
         accAlign = align;

src/drivers/accgyro_mpu6050.h

@@ -1,5 +1,5 @@
 #pragma once
 
-bool mpu6050Detect(sensor_t * acc, sensor_t * gyro, uint16_t lpf, uint8_t *scale);
+bool mpu6050Detect(sensor_t * acc, sensor_t * gyro, uint16_t lpf);
 void mpu6050DmpLoop(void);
 void mpu6050DmpResetFifo(void);

src/flight_imu.c

@@ -3,6 +3,7 @@
 
 #include "common/maths.h"
 
+#include "sensors_gyro.h"
 #include "sensors_compass.h"
 
 #include "flight_common.h"

src/mw.c

@@ -4,6 +4,7 @@
 #include "common/maths.h"
 #include "common/typeconversion.h"
 
+#include "sensors_gyro.h"
 #include "flight_common.h"
 #include "serial_cli.h"
 #include "telemetry_common.h"

src/mw.h

@@ -90,9 +90,6 @@ extern uint8_t  GPS_svinfo_quality[16];                      // Bitfield Qualtit
 extern uint8_t  GPS_svinfo_cno[16];                          // Carrier to Noise Ratio (Signal Strength)
 
 extern flags_t f;
-extern sensor_t acc;
-extern sensor_t gyro;
-extern baro_t baro;
 
 // main
 void setPIDController(int type);

src/runtime_config.h

@@ -53,7 +53,6 @@ typedef struct core_t {
     serialPort_t *gpsport;
     serialPort_t *telemport;
     serialPort_t *rcvrport;
-    uint8_t mpu6050_scale;                  // es/non-es variance between MPU6050 sensors, half my boards are mpu6000ES, need this to be dynamic. automatically set by mpu6050 driver.
 } core_t;
 
 typedef void (* pidControllerFuncPtr)(void);                // pid controller function prototype

src/sensors_acceleration.c

@@ -4,6 +4,10 @@
 
 #include "mw.h"
 
+#include "sensors_acceleration.h"
+
+sensor_t acc;                       // acc access functions
+uint8_t accHardware = ACC_DEFAULT;  // which accel chip is used/detected
 
 uint16_t calibratingA = 0;      // the calibration is done is the main loop. Calibrating decreases at each cycle down to 0, then we enter in a normal mode.
 

src/sensors_acceleration.h

@@ -10,5 +10,9 @@ typedef enum AccelSensors {
     ACC_NONE = 5
 } AccelSensors;
 
+extern uint8_t accHardware;
+extern sensor_t acc;
+
 void ACC_Common(void);
 void ACC_getADC(void);
+

src/sensors_barometer.c

@@ -1,6 +1,8 @@
 #include "board.h"
 #include "mw.h"
 
+baro_t baro;                        // barometer access functions
+
 #ifdef BARO
 void Baro_Common(void)
 {

src/sensors_barometer.h

@@ -1,5 +1,7 @@
 #pragma once
 
+extern baro_t baro;
+
 #ifdef BARO
 void Baro_Common(void);
 int Baro_update(void);

src/sensors_common.h

@@ -31,6 +31,7 @@ typedef struct sensor_t
     sensorReadFuncPtr read;                                 // read 3 axis data function
     sensorReadFuncPtr temperature;                          // read temperature if available
     float scale;                                            // scalefactor (currently used for gyro only, todo for accel)
+    char revisionCode;                                      // a revision code for the sensor, if known
 } sensor_t;
 
 extern int16_t heading;

src/sensors_gyro.c

@@ -6,6 +6,8 @@
 #include "flight_common.h"
 #include "statusindicator.h"
 
+sensor_t gyro;                      // gyro access functions
+
 void GYRO_Common(void)
 {
     int axis;

src/sensors_gyro.h

@@ -1,4 +1,7 @@
 #pragma once
 
+extern sensor_t gyro;
+
 void GYRO_Common(void);
 void Gyro_getADC(void);
+

src/sensors_initialisation.c

@@ -2,6 +2,10 @@
 #include "mw.h"
 
 #include "sensors_acceleration.h"
+#include "sensors_barometer.h"
+#include "sensors_gyro.h"
+
+#include "sensors_common.h"
 
 uint16_t calibratingB = 0;      // baro calibration = get new ground pressure value
 uint16_t calibratingG = 0;
@@ -12,15 +16,12 @@ extern uint16_t batteryWarningVoltage;
 extern uint8_t batteryCellCount;
 extern float magneticDeclination;
 
-sensor_t acc;                       // acc access functions
-sensor_t gyro;                      // gyro access functions
-baro_t baro;                        // barometer access functions
-uint8_t accHardware = ACC_DEFAULT;  // which accel chip is used/detected
-
 #ifdef FY90Q
 // FY90Q analog gyro/acc
 void sensorsAutodetect(void)
 {
+    memset(&acc, sizeof(acc), 0);
+    memset(&gyro, sizeof(gyro), 0);
     adcSensorInit(&acc, &gyro);
 }
 #else
@@ -31,8 +32,11 @@ void sensorsAutodetect(void)
     drv_adxl345_config_t acc_params;
     bool haveMpu6k = false;
 
+    memset(&acc, sizeof(acc), 0);
+    memset(&gyro, sizeof(gyro), 0);
+
     // Autodetect gyro hardware. We have MPU3050 or MPU6050.
-    if (mpu6050Detect(&acc, &gyro, mcfg.gyro_lpf, &core.mpu6050_scale)) {
+    if (mpu6050Detect(&acc, &gyro, mcfg.gyro_lpf)) {
         // this filled up  acc.* struct with init values
         haveMpu6k = true;
     } else if (l3g4200dDetect(&gyro, mcfg.gyro_lpf)) {
@@ -60,7 +64,7 @@ retry:
             ; // fallthrough
         case ACC_MPU6050: // MPU6050
             if (haveMpu6k) {
-                mpu6050Detect(&acc, &gyro, mcfg.gyro_lpf, &core.mpu6050_scale); // yes, i'm rerunning it again.  re-fill acc struct
+                mpu6050Detect(&acc, &gyro, mcfg.gyro_lpf); // yes, i'm rerunning it again.  re-fill acc struct
                 accHardware = ACC_MPU6050;
                 if (mcfg.acc_hardware == ACC_MPU6050)
                     break;

src/serial_cli.c

@@ -30,7 +30,6 @@ static void cliVersion(char *cmdline);
 
 // from sensors.c
 extern uint8_t batteryCellCount;
-extern uint8_t accHardware;
 
 // from config.c RC Channel mapping
 extern const char rcChannelLetters[];
@@ -996,8 +995,8 @@ static void cliStatus(char *cmdline)
     }
     if (sensors(SENSOR_ACC)) {
         printf("ACCHW: %s", accNames[accHardware]);
-        if (accHardware == ACC_MPU6050)
+        if (acc.revisionCode)
-            printf(".%c", core.mpu6050_scale ? 'o' : 'n');
+            printf(".%c", acc.revisionCode);
     }
     cliPrint("\r\n");