关于arduino：从uint8_t *到uint8_t无效的转换

Invalid Conversion from uint8_t* to uint8_t fpermissive c++

我知道这个问题已经问过很多遍了，但是在阅读了许多类似的问题后，我仍然无法理解和解决这个问题。我是一个新手程序员，仍在学习中，而且很多天来我一直无法解决这个问题。

我正在使用来自arduino的演示代码库，并尝试在c ++ Atmel Studio 7中进行编译(针对我基于ATSAMD21制作的自定义板进行编译)。这是我的相关代码(删除了所有不相关的部分)：

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#include <Arduino.h>
#include <Wire.h>
#include"Kalman.h" // Source: https://github.com/TKJElectronics/KalmanFilter
//Beginning of Auto generated function prototypes by Atmel Studio
uint8_t i2cWrite(uint8_t registerAddress, uint8_t data, bool sendStop);
uint8_t i2cWrite(uint8_t registerAddress, uint8_t data, uint8_t length, bool sendStop);
uint8_t i2cRead(uint8_t registerAddress, uint8_t data, uint8_t nbytes);
//End of Auto generated function prototypes by Atmel Studio

#define RESTRICT_PITCH // Comment out to restrict roll to ±90deg instead - please read: http://www.freescale.com/files/sensors/doc/app_note/AN3461.pdf

Kalman kalmanX; // Create the Kalman instances
Kalman kalmanY;

/* IMU Data */
double accX, accY, accZ;
double gyroX, gyroY, gyroZ;
int16_t tempRaw;

double gyroXangle, gyroYangle; // Angle calculate using the gyro only
double compAngleX, compAngleY; // Calculated angle using a complementary filter
double kalAngleX, kalAngleY; // Calculated angle using a Kalman filter

uint32_t timer;
uint8_t i2cData[14]; // Buffer for I2C data

// TODO: Make calibration routine

#if defined(ARDUINO_SAMD_ZERO) && defined(SERIAL_PORT_USBVIRTUAL)
// Required for Serial on Zero based boards
#define Serial SERIAL_PORT_USBVIRTUAL
#endif

void setup() {
Serial.begin(115200);
Wire.begin();
//TWBR = ((F_CPU / 400000L) - 16) / 2; // Set I2C frequency to 400kHz

i2cData[0] = 7; // Set the sample rate to 1000Hz - 8kHz/(7+1) = 1000Hz
i2cData[1] = 0x00; // Disable FSYNC and set 260 Hz Acc filtering, 256 Hz Gyro filtering, 8 KHz sampling
i2cData[2] = 0x00; // Set Gyro Full Scale Range to ±250deg/s
i2cData[3] = 0x00; // Set Accelerometer Full Scale Range to ±2g
while (i2cWrite(0x19, *i2cData, 4, false)); // Write to all four registers at once
while (i2cWrite(0x6B, 0x01, true)); // PLL with X axis gyroscope reference and disable sleep mode

while (i2cRead(0x75, *i2cData, 1));
if (i2cData[0] != 0x68) { // Read"WHO_AM_I" register
Serial.print(F("Error reading sensor"));
while (1);
}

//delay(100); // Wait for sensor to stabilize

/* Set kalman and gyro starting angle */
while (i2cRead(0x3B, *i2cData, 6));
accX = (i2cData[0] << 8) | i2cData[1];
accY = (i2cData[2] << 8) | i2cData[3];
accZ = (i2cData[4] << 8) | i2cData[5];

// Source: http://www.freescale.com/files/sensors/doc/app_note/AN3461.pdf eq. 25 and eq. 26
// atan2 outputs the value of -π to π (radians) - see http://en.wikipedia.org/wiki/Atan2
// It is then converted from radians to degrees
#ifdef RESTRICT_PITCH // Eq. 25 and 26
double roll = atan2(accY, accZ) * RAD_TO_DEG;
double pitch = atan(-accX / sqrt(accY * accY + accZ * accZ)) * RAD_TO_DEG;
#else // Eq. 28 and 29
double roll = atan(accY / sqrt(accX * accX + accZ * accZ)) * RAD_TO_DEG;
double pitch = atan2(-accX, accZ) * RAD_TO_DEG;
#endif

kalmanX.setAngle(roll); // Set starting angle
kalmanY.setAngle(pitch);
gyroXangle = roll;
gyroYangle = pitch;
compAngleX = roll;
compAngleY = pitch;

timer = micros();
}

void loop() {
/* Update all the values */
while (i2cRead(0x3B, *i2cData, 14));
accX = ((i2cData[0] << 8) | i2cData[1]);
accY = ((i2cData[2] << 8) | i2cData[3]);
accZ = ((i2cData[4] << 8) | i2cData[5]);
tempRaw = (i2cData[6] << 8) | i2cData[7];
gyroX = (i2cData[8] << 8) | i2cData[9];
gyroY = (i2cData[10] << 8) | i2cData[11];
gyroZ = (i2cData[12] << 8) | i2cData[13];

double dt = (double)(micros() - timer) / 1000000; // Calculate delta time
timer = micros();

// Source: http://www.freescale.com/files/sensors/doc/app_note/AN3461.pdf eq. 25 and eq. 26
// atan2 outputs the value of -π to π (radians) - see http://en.wikipedia.org/wiki/Atan2
// It is then converted from radians to degrees
#ifdef RESTRICT_PITCH // Eq. 25 and 26
double roll = atan2(accY, accZ) * RAD_TO_DEG;
double pitch = atan(-accX / sqrt(accY * accY + accZ * accZ)) * RAD_TO_DEG;
#else // Eq. 28 and 29
double roll = atan(accY / sqrt(accX * accX + accZ * accZ)) * RAD_TO_DEG;
double pitch = atan2(-accX, accZ) * RAD_TO_DEG;
#endif

double gyroXrate = gyroX / 131.0; // Convert to deg/s
double gyroYrate = gyroY / 131.0; // Convert to deg/s

#ifdef RESTRICT_PITCH
// This fixes the transition problem when the accelerometer angle jumps between -180 and 180 degrees
if ((roll < -90 && kalAngleX > 90) || (roll > 90 && kalAngleX < -90)) {
kalmanX.setAngle(roll);
compAngleX = roll;
kalAngleX = roll;
gyroXangle = roll;
} else
kalAngleX = kalmanX.getAngle(roll, gyroXrate, dt); // Calculate the angle using a Kalman filter

if (abs(kalAngleX) > 90)
gyroYrate = -gyroYrate; // Invert rate, so it fits the restriced accelerometer reading
kalAngleY = kalmanY.getAngle(pitch, gyroYrate, dt);
#else
// This fixes the transition problem when the accelerometer angle jumps between -180 and 180 degrees
if ((pitch < -90 && kalAngleY > 90) || (pitch > 90 && kalAngleY < -90)) {
kalmanY.setAngle(pitch);
compAngleY = pitch;
kalAngleY = pitch;
gyroYangle = pitch;
} else
kalAngleY = kalmanY.getAngle(pitch, gyroYrate, dt); // Calculate the angle using a Kalman filter

if (abs(kalAngleY) > 90)
gyroXrate = -gyroXrate; // Invert rate, so it fits the restriced accelerometer reading
kalAngleX = kalmanX.getAngle(roll, gyroXrate, dt); // Calculate the angle using a Kalman filter
#endif

gyroXangle += gyroXrate * dt; // Calculate gyro angle without any filter
gyroYangle += gyroYrate * dt;
//gyroXangle += kalmanX.getRate() * dt; // Calculate gyro angle using the unbiased rate
//gyroYangle += kalmanY.getRate() * dt;

compAngleX = 0.93 * (compAngleX + gyroXrate * dt) + 0.07 * roll; // Calculate the angle using a Complimentary filter
compAngleY = 0.93 * (compAngleY + gyroYrate * dt) + 0.07 * pitch;

// Reset the gyro angle when it has drifted too much
if (gyroXangle < -180 || gyroXangle > 180)
gyroXangle = kalAngleX;
if (gyroYangle < -180 || gyroYangle > 180)
gyroYangle = kalAngleY;

uint32_t time = millis();

/* Print Data */
#if 1 // Set to 1 to activate
Serial.print(accX); Serial.print("\t");
Serial.print(accY); Serial.print("\t");
Serial.print(accZ); Serial.print("\t");

Serial.print(gyroX); Serial.print("\t");
Serial.print(gyroY); Serial.print("\t");
Serial.print(gyroZ); Serial.print("\t");

Serial.print(time); Serial.print("\t");

Serial.print("\t");
#endif
#if 0
Serial.print(roll); Serial.print("\t");
Serial.print(gyroXangle); Serial.print("\t");
Serial.print(compAngleX); Serial.print("\t");
Serial.print(kalAngleX); Serial.print("\t");

Serial.print("\t");

Serial.print(pitch); Serial.print("\t");
Serial.print(gyroYangle); Serial.print("\t");
Serial.print(compAngleY); Serial.print("\t");
Serial.print(kalAngleY); Serial.print("\t");
#endif
#if 1 // Set to 1 to print the temperature
Serial.print("\t");

double temperature = (double)tempRaw / 340.0 + 36.53;
Serial.print(temperature); Serial.print("\t");
#endif

Serial.print("

");
//delay(2);
}

const uint8_t IMUAddress = 0x68; // AD0 is logic low on the PCB
const uint16_t I2C_TIMEOUT = 1000; // Used to check for errors in I2C communication

uint8_t i2cWrite(uint8_t registerAddress, uint8_t data, bool sendStop) {
return i2cWrite(registerAddress, &data, 1, sendStop); // INVALID CONVERSION ERROR HERE
}

uint8_t i2cWrite(uint8_t registerAddress, uint8_t *data, uint8_t length, bool sendStop) {
Wire.beginTransmission(IMUAddress);
Wire.write(registerAddress);
Wire.write(data, length);
uint8_t rcode = Wire.endTransmission(sendStop); // Returns 0 on success
if (rcode) {
Serial.print(F("i2cWrite failed:"));
Serial.println(rcode);
}
return rcode; // See: http://arduino.cc/en/Reference/WireEndTransmission
}

uint8_t i2cRead(uint8_t registerAddress, uint8_t *data, uint8_t nbytes) {
uint32_t timeOutTimer;
Wire.beginTransmission(IMUAddress);
Wire.write(registerAddress);
uint8_t rcode = Wire.endTransmission(false); // Don't release the bus
if (rcode) {
Serial.print(F("i2cRead failed:"));
Serial.println(rcode);
return rcode; // See: http://arduino.cc/en/Reference/WireEndTransmission
}
Wire.requestFrom(IMUAddress, nbytes, (uint8_t)true); // Send a repeated start and then release the bus after reading
for (uint8_t i = 0; i < nbytes; i++) {
if (Wire.available())
data[i] = Wire.read();
else {
timeOutTimer = micros();
while (((micros() - timeOutTimer) < I2C_TIMEOUT) && !Wire.available());
if (Wire.available())
data[i] = Wire.read();
else {
Serial.println(F("i2cRead timeout"));
return 5; // This error value is not already taken by endTransmission
}
}
}
return 0; // Success
}

上面的代码在第1195行第54行的i2cWrite函数中给出了错误：

从'uint8_t * {aka unsigned char *}'到'uint8_t {aka unsigned char}'的无效转换-fpermissive

请注意，我首先修改了上面的代码，并在第43、46、55、83行的i2cWrite / i2cRead数组中添加了一个*星号。如果我不添加这些星号，那么所有这些行也将出现相同的确切错误。由于原始代码没有这些*引用，也许我不应该添加这些指针...？

我试图学习有关指针和引用的信息，但是很费劲。对于我的一生，我无法理解如何解决此错误。我已经尝试过各种＆和*，但是我一生无法理解和纠正此问题。我似乎无法理解我的代码如何/在哪里尝试将uint8_t *分配给uint8_t。

对于其他主题，我是否需要将volatile或const强制转换或使用这些变量中的任何一个？我不这么认为，但我还是一个初学者。

非常感谢任何人向我指出正确的方向或帮助我理解解决方案。在Arduino中，我可以编译并运行此代码，但在Atmel Studio中则不能。任何帮助深表感谢。

编辑：我已经更新了代码并删除了注释，以便错误和行号与我的帖子匹配。抱歉，在线上出现混乱。