Read Switch controller gyro/accel sensitivity coeffs (SDL3)

These vary by controller, so using the stored values should improve the accuracy of the sensor data.

(cherry picked from commit 558a89fdb6)
This commit is contained in:
ceski
2025-06-13 07:46:14 -07:00
committed by Sam Lantinga
parent ad8e517227
commit a96dc76831

View File

@@ -58,9 +58,7 @@
#define SWITCH_GYRO_SCALE 14.2842f
#define SWITCH_ACCEL_SCALE 4096.f
#define SWITCH_GYRO_SCALE_OFFSET 13371.0f
#define SWITCH_GYRO_SCALE_MULT 936.0f
#define SWITCH_ACCEL_SCALE_OFFSET 16384.0f
#define SWITCH_ACCEL_SCALE_MULT 4.0f
enum
@@ -1044,6 +1042,8 @@ static bool LoadIMUCalibration(SDL_DriverSwitch_Context *ctx)
if (WriteSubcommand(ctx, k_eSwitchSubcommandIDs_SPIFlashRead, (uint8_t *)&readParams, sizeof(readParams), &reply)) {
Uint8 *pIMUScale;
Sint16 sAccelRawX, sAccelRawY, sAccelRawZ, sGyroRawX, sGyroRawY, sGyroRawZ;
Sint16 sAccelSensCoeffX, sAccelSensCoeffY, sAccelSensCoeffZ;
Sint16 sGyroSensCoeffX, sGyroSensCoeffY, sGyroSensCoeffZ;
// IMU scale gives us multipliers for converting raw values to real world values
pIMUScale = reply->spiReadData.rgucReadData;
@@ -1052,10 +1052,18 @@ static bool LoadIMUCalibration(SDL_DriverSwitch_Context *ctx)
sAccelRawY = (pIMUScale[3] << 8) | pIMUScale[2];
sAccelRawZ = (pIMUScale[5] << 8) | pIMUScale[4];
sAccelSensCoeffX = (pIMUScale[7] << 8) | pIMUScale[6];
sAccelSensCoeffY = (pIMUScale[9] << 8) | pIMUScale[8];
sAccelSensCoeffZ = (pIMUScale[11] << 8) | pIMUScale[10];
sGyroRawX = (pIMUScale[13] << 8) | pIMUScale[12];
sGyroRawY = (pIMUScale[15] << 8) | pIMUScale[14];
sGyroRawZ = (pIMUScale[17] << 8) | pIMUScale[16];
sGyroSensCoeffX = (pIMUScale[19] << 8) | pIMUScale[18];
sGyroSensCoeffY = (pIMUScale[21] << 8) | pIMUScale[20];
sGyroSensCoeffZ = (pIMUScale[23] << 8) | pIMUScale[22];
// Check for user calibration data. If it's present and set, it'll override the factory settings
readParams.unAddress = k_unSPIIMUUserScaleStartOffset;
readParams.ucLength = k_unSPIIMUUserScaleLength;
@@ -1072,14 +1080,14 @@ static bool LoadIMUCalibration(SDL_DriverSwitch_Context *ctx)
}
// Accelerometer scale
ctx->m_IMUScaleData.fAccelScaleX = SWITCH_ACCEL_SCALE_MULT / (SWITCH_ACCEL_SCALE_OFFSET - (float)sAccelRawX) * SDL_STANDARD_GRAVITY;
ctx->m_IMUScaleData.fAccelScaleY = SWITCH_ACCEL_SCALE_MULT / (SWITCH_ACCEL_SCALE_OFFSET - (float)sAccelRawY) * SDL_STANDARD_GRAVITY;
ctx->m_IMUScaleData.fAccelScaleZ = SWITCH_ACCEL_SCALE_MULT / (SWITCH_ACCEL_SCALE_OFFSET - (float)sAccelRawZ) * SDL_STANDARD_GRAVITY;
ctx->m_IMUScaleData.fAccelScaleX = SWITCH_ACCEL_SCALE_MULT / ((float)sAccelSensCoeffX - (float)sAccelRawX) * SDL_STANDARD_GRAVITY;
ctx->m_IMUScaleData.fAccelScaleY = SWITCH_ACCEL_SCALE_MULT / ((float)sAccelSensCoeffY - (float)sAccelRawY) * SDL_STANDARD_GRAVITY;
ctx->m_IMUScaleData.fAccelScaleZ = SWITCH_ACCEL_SCALE_MULT / ((float)sAccelSensCoeffZ - (float)sAccelRawZ) * SDL_STANDARD_GRAVITY;
// Gyro scale
ctx->m_IMUScaleData.fGyroScaleX = SWITCH_GYRO_SCALE_MULT / (SWITCH_GYRO_SCALE_OFFSET - (float)sGyroRawX) * SDL_PI_F / 180.0f;
ctx->m_IMUScaleData.fGyroScaleY = SWITCH_GYRO_SCALE_MULT / (SWITCH_GYRO_SCALE_OFFSET - (float)sGyroRawY) * SDL_PI_F / 180.0f;
ctx->m_IMUScaleData.fGyroScaleZ = SWITCH_GYRO_SCALE_MULT / (SWITCH_GYRO_SCALE_OFFSET - (float)sGyroRawZ) * SDL_PI_F / 180.0f;
ctx->m_IMUScaleData.fGyroScaleX = SWITCH_GYRO_SCALE_MULT / ((float)sGyroSensCoeffX - (float)sGyroRawX) * SDL_PI_F / 180.0f;
ctx->m_IMUScaleData.fGyroScaleY = SWITCH_GYRO_SCALE_MULT / ((float)sGyroSensCoeffY - (float)sGyroRawY) * SDL_PI_F / 180.0f;
ctx->m_IMUScaleData.fGyroScaleZ = SWITCH_GYRO_SCALE_MULT / ((float)sGyroSensCoeffZ - (float)sGyroRawZ) * SDL_PI_F / 180.0f;
} else {
// Use default values