From f5d1402c287963bf71f7a4cf14f16bbedffae143 Mon Sep 17 00:00:00 2001
From: Aubrey Hesselgren <[EMAIL REDACTED]>
Date: Fri, 13 Jun 2025 22:29:19 -0700
Subject: [PATCH] Flydigi Vader 4 Pro IMU rate correction (#13215)
Flydigi IMU rate now matches observed rate of packets in both dongle and wired connection.
Flydigi Vader 4 Pro IMU rate correction was set at a fixed 125hz. In actuality rate is 1000hz over dongle and 500hz when wired.
---
src/joystick/hidapi/SDL_hidapi_flydigi.c | 49 ++++++++++++++++--------
1 file changed, 33 insertions(+), 16 deletions(-)
diff --git a/src/joystick/hidapi/SDL_hidapi_flydigi.c b/src/joystick/hidapi/SDL_hidapi_flydigi.c
index 29929f80c70c5..ac012e6600f6d 100644
--- a/src/joystick/hidapi/SDL_hidapi_flydigi.c
+++ b/src/joystick/hidapi/SDL_hidapi_flydigi.c
@@ -42,7 +42,13 @@ enum
SDL_GAMEPAD_NUM_BASE_FLYDIGI_BUTTONS
};
-#define SENSOR_INTERVAL_NS 8000000ULL
+/* Rate of IMU Sensor Packets over wireless Dongle observed in testcontroller tool at 1000hz */
+#define SENSOR_INTERVAL_VADER4_PRO_DONGLE_RATE_HZ 1000
+#define SENSOR_INTERVAL_VADER4_PRO_DONGLE_NS (SDL_NS_PER_SECOND / SENSOR_INTERVAL_VADER4_PRO_DONGLE_RATE_HZ)
+/* Rate of IMU Sensor Packets over wired observed in testcontroller tool connection at 500hz */
+#define SENSOR_INTERVAL_VADER_PRO4_WIRED_RATE_HZ 500
+#define SENSOR_INTERVAL_VADER_PRO4_WIRED_NS (SDL_NS_PER_SECOND / SENSOR_INTERVAL_VADER_PRO4_WIRED_RATE_HZ)
+
#define FLYDIGI_CMD_REPORT_ID 0x05
#define FLYDIGI_HAPTIC_COMMAND 0x0F
#define FLYDIGI_GET_CONFIG_COMMAND 0xEB
@@ -58,7 +64,8 @@ typedef struct
bool sensors_supported;
bool sensors_enabled;
Uint16 firmware_version;
- Uint64 sensor_timestamp; // Microseconds. Simulate onboard clock. Advance by known rate: SENSOR_INTERVAL_NS == 8ms = 125 Hz
+ Uint64 sensor_timestamp_ns; // Simulate onboard clock. Advance by known time step. Nanoseconds.
+ Uint64 sensor_timestamp_step_ns; // Based on observed rate of receipt of IMU sensor packets.
float accelScale;
Uint8 last_state[USB_PACKET_LENGTH];
} SDL_DriverFlydigi_Context;
@@ -163,6 +170,10 @@ static void UpdateDeviceIdentity(SDL_HIDAPI_Device *device)
}
device->guid.data[15] = ctx->deviceID;
+ // This is the previous sensor default of 125hz.
+ // Override this in the switch statement below based on observed sensor packet rate.
+ ctx->sensor_timestamp_step_ns = SDL_NS_PER_SECOND / 125;
+
switch (ctx->deviceID) {
case 19:
HIDAPI_SetDeviceName(device, "Flydigi Apex 2");
@@ -197,12 +208,14 @@ static void UpdateDeviceIdentity(SDL_HIDAPI_Device *device)
ctx->has_cz = true;
ctx->sensors_supported = true;
ctx->accelScale = SDL_STANDARD_GRAVITY / 256.0f;
+ ctx->sensor_timestamp_step_ns = ctx->wireless ? SENSOR_INTERVAL_VADER4_PRO_DONGLE_NS : SENSOR_INTERVAL_VADER_PRO4_WIRED_NS;
break;
case 85:
HIDAPI_SetDeviceName(device, "Flydigi Vader 4 Pro");
ctx->has_cz = true;
ctx->sensors_supported = true;
ctx->accelScale = SDL_STANDARD_GRAVITY / 256.0f;
+ ctx->sensor_timestamp_step_ns = ctx->wireless ? SENSOR_INTERVAL_VADER4_PRO_DONGLE_NS : SENSOR_INTERVAL_VADER_PRO4_WIRED_NS;
break;
default:
break;
@@ -256,8 +269,10 @@ static bool HIDAPI_DriverFlydigi_OpenJoystick(SDL_HIDAPI_Device *device, SDL_Joy
}
if (ctx->sensors_supported) {
- SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_GYRO, 125.0f);
- SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_ACCEL, 125.0f);
+
+ const float flSensorRate = ctx->wireless ? (float)SENSOR_INTERVAL_VADER4_PRO_DONGLE_RATE_HZ : (float)SENSOR_INTERVAL_VADER_PRO4_WIRED_RATE_HZ;
+ SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_GYRO, flSensorRate);
+ SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_ACCEL, flSensorRate);
}
return true;
@@ -411,18 +426,20 @@ static void HIDAPI_DriverFlydigi_HandleStatePacket(SDL_Joystick *joystick, SDL_D
Uint64 sensor_timestamp;
float values[3];
- // Note: we cannot use the time stamp of the receiving computer due to packet delay creating "spiky" timings.
- // The imu time stamp is intended to be the sample time of the on-board hardware.
- // 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;
-
- // This device's IMU values are reported differently from SDL
- // Thus we perform a rotation of the coordinate system to match the SDL standard.
- values[0] = -LOAD16(data[26], data[27]) * DEG2RAD(65536) / INT16_MAX; // Rotation around pitch axis
- values[1] = -LOAD16(data[18], data[20]) * DEG2RAD(65536) / INT16_MAX; // Rotation around yaw axis
- values[2] = -LOAD16(data[29], data[30]) * DEG2RAD(1024) / INT16_MAX; // Rotation around roll axis
+ // Advance the imu sensor time stamp based on the observed rate of receipt of packets in the testcontroller app.
+ // This varies between Product ID and connection type.
+ sensor_timestamp = ctx->sensor_timestamp_ns;
+ ctx->sensor_timestamp_ns += ctx->sensor_timestamp_step_ns;
+
+ // Pitch and yaw scales may be receiving extra filtering for the sake of bespoke direct mouse output.
+ // As result, roll has a different scaling factor than pitch and yaw.
+ // These values were estimated using the testcontroller tool in lieux of hard data sheet references.
+ const float flPitchAndYawScale = DEG2RAD(72000.0f);
+ const float flRollScale = DEG2RAD(1200.0f);
+ values[0] = HIDAPI_RemapVal(-1.0f * LOAD16(data[26], data[27]), INT16_MIN, INT16_MAX, -flPitchAndYawScale, flPitchAndYawScale);
+ values[1] = HIDAPI_RemapVal(-1.0f * LOAD16(data[18], data[20]), INT16_MIN, INT16_MAX, -flPitchAndYawScale, flPitchAndYawScale);
+ values[2] = HIDAPI_RemapVal(-1.0f * LOAD16(data[29], data[30]), INT16_MIN, INT16_MAX, -flRollScale, flRollScale);
+
SDL_SendJoystickSensor(timestamp, joystick, SDL_SENSOR_GYRO, sensor_timestamp, values, 3);
values[0] = -LOAD16(data[11], data[12]) * ctx->accelScale; // Acceleration along pitch axis