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8 bitdo polling rate corrections (#13221) 

Gathered correct IMU polling rate in wired mode for good gyro synchronization.

Wireless: different models had different amounts of Bluetooth packet loss.
USB_PRODUCT_8BITDO_ULTIMATE2_WIRELESS: Solid 120hz over bluetooth (note: only appears via).
USB_PRODUCT_8BITDO_PRO_2_BT: Lossy - 80-90hz registered.
SB_PRODUCT_8BITDO_SN30_PRO_BT & USB_PRODUCT_8BITDO_SN30_PRO_BT: Very Lossy - 60-90hz registered
This commit is contained in:
Aubrey Hesselgren 2025-06-13 22:25:31 -07:00 committed by GitHub
parent 913b611ccd
commit 1e886c8a2f
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GPG Key ID: B5690EEEBB952194
1 changed files with 30 additions and 6 deletions
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36
src/joystick/hidapi/SDL_hidapi_8bitdo.c
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@ -48,8 +48,6 @@ enum
#define SDL_8BITDO_BT_REPORTID_SDL_REPORTID 0x01
#define ABITDO_ACCEL_SCALE 4096.f
#define ABITDO_SENSOR_POLLING_RATE 125.f
#define SENSOR_INTERVAL_NS 8000000ULL
#define ABITDO_GYRO_MAX_DEGREES_PER_SECOND 2000.f
typedef struct
@ -69,7 +67,8 @@ typedef struct
float accelScale;
float gyroScale;
Uint8 last_state[USB_PACKET_LENGTH];
Uint64 sensor_timestamp; // Nanoseconds. Simulate onboard clock. Advance by known rate: SENSOR_INTERVAL_NS == 8ms = 125 Hz
Uint64 sensor_timestamp; // Nanoseconds. Simulate onboard clock. Different models have different rates vs different connection styles.
Uint64 sensor_timestamp_interval;
} SDL_Driver8BitDo_Context;
#pragma pack(push,1)
@ -217,6 +216,27 @@ static void HIDAPI_Driver8BitDo_SetDevicePlayerIndex(SDL_HIDAPI_Device *device,
{
}
static Uint64 HIDAPI_Driver8BitDo_GetIMURateForProductID(SDL_HIDAPI_Device *device)
{
// TODO: If sensor time stamp is sent, these fixed settings from observation can be replaced
switch (device->product_id) {
// Note, This is estimated by observation of Bluetooth packets received in the testcontroller tool
case USB_PRODUCT_8BITDO_SN30_PRO_BT:
case USB_PRODUCT_8BITDO_SF30_PRO_BT:
return 90; // Observed to be anywhere between 60-90 hz. Possibly lossy in current state
case USB_PRODUCT_8BITDO_SF30_PRO:
case USB_PRODUCT_8BITDO_SN30_PRO:
return 100;
case USB_PRODUCT_8BITDO_PRO_2:
case USB_PRODUCT_8BITDO_PRO_2_BT:// Note, labelled as "BT" but appears this way when wired. Observed bluetooth packet rate seems to be 80-90hz
return (device->is_bluetooth ? 85 : 100);
case USB_PRODUCT_8BITDO_ULTIMATE2_WIRELESS:
default:
return 120;
break;
}
}
#ifndef DEG2RAD
#define DEG2RAD(x) ((float)(x) * (float)(SDL_PI_F / 180.f))
#endif
@ -242,9 +262,13 @@ static bool HIDAPI_Driver8BitDo_OpenJoystick(SDL_HIDAPI_Device *device, SDL_Joys
joystick->nhats = 1;
if (ctx->sensors_supported) {
SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_GYRO, ABITDO_SENSOR_POLLING_RATE);
SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_ACCEL, ABITDO_SENSOR_POLLING_RATE);
// Different 8Bitdo controllers in different connection modes have different polling rates.
const Uint64 imu_polling_rate = HIDAPI_Driver8BitDo_GetIMURateForProductID(device);
ctx->sensor_timestamp_interval = SDL_NS_PER_SECOND / imu_polling_rate;
SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_GYRO, (float)imu_polling_rate);
SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_ACCEL, (float)imu_polling_rate);
ctx->accelScale = SDL_STANDARD_GRAVITY / ABITDO_ACCEL_SCALE;
// Hardware senses +/- N Degrees per second mapped to +/- INT16_MAX
@ -525,7 +549,7 @@ static void HIDAPI_Driver8BitDo_HandleStatePacket(SDL_Joystick *joystick, SDL_Dr
// In the absence of time stamp data from the data[], we can simulate that by
// advancing a time stamp by the observed/known imu clock rate. This is 8ms = 125 Hz
sensor_timestamp = ctx->sensor_timestamp;
ctx->sensor_timestamp += SENSOR_INTERVAL_NS;
ctx->sensor_timestamp += ctx->sensor_timestamp_interval;
// This device's IMU values are reported differently from SDL
// Thus we perform a rotation of the coordinate system to match the SDL standard.