C-20D Horizontal 2-Axis FPV Gimbal
Specifications
- Product: C-20D Horizontal 2-Axis FPV Gimbal
- Document Version: V1.4 2025.06
- Input Voltage: 7.4V~26.4V
- Supported Cameras: Refer to Appendix 1 in the user manual
- Control Methods: Headtracker Direct Control, S.BUS / CRSF
Control, PWM Control, MAVLink Control - Gimbal Modes: Refer to Gimbal Modes section
Product Usage Instructions
Installation of C-20D with O4 Pro Lens
- Remove the housing fixing screws of the camera (one on each
side) and separate the front and rear housings of the camera. Be
careful not to damage the camera while separating the
housings. - Use the crowbar provided in the package to disconnect the
coaxial cable from the camera and remove the rear housing. Handle
the coaxial cable and connectors carefully to avoid damage.
Controlling the C-20D
The C-20D gimbal can be controlled through various methods:
- Private Protocol Control
- Headtracker Direct Control
- S.BUS / CRSF Control
- PWM Control
- MAVLink Control
Gimbal Modes and Sensitivity Adjustment
The gimbal supports different modes for operation. Users can
adjust the sensitivity settings based on their requirements.
Configuring, Calibrating & Firmware Upgrading
Refer to the user manual for detailed instructions on how to
configure, calibrate, and upgrade the firmware of the gimbal.
Parameter Configuration Basic Operation
Ensure proper parameter configuration for basic operations.
Follow the guidelines provided in the manual for a seamless user
experience.
Frequently Asked Questions (FAQ)
Q: What should I do if my gimbal is not responding
correctly?
A: Check the power supply, connectors, and installation of the
gimbal. Ensure that all connections are secure and follow the
troubleshooting steps in the user manual.
Q: Can children use this product?
A: This product is not intended for use by children. Always keep
it away from children and handle it with care.
V1.4 2025.06
C-20D
Horizontal 2-Axis FPV Gimbal User Manual
©2025 XF All Rights Reserved
Using this Manual Legend
Important
Tips
Explanation
Revision History
Date 2024.05.30
Date 2024.11.19
Date 2024.12.19
Date 2025.06.04
Document Version V1.0
Document Version V1.1
Document Version V1.2
Document Version V1.4
Caution
Always stay alert when using C-20D 2-axis FPV Gimbal and its accessories to control an unmanned aerial vehicle (UAV) or other carriers. Careless may result in serious harm to yourself and others.
1. Make sure that the external power supply for the gimbal is a lithium battery (2S~6S) with an input voltage between 7.4V~26.4V. Otherwise, the gimbal may work abnormally or be damaged.
2. DO NOT short circuit the power output and GND. Otherwise, the equipment may be damaged and may not work properly.
3. Follow the instructions in the user manual when installing the gimbal. Incorrect installation may cause the gimbal to not work properly.
4. Make sure that all connectors are secure and all parts are work properly. 5. Make sure you fully understand and abide by local laws and regulations
before using this product. 6. This product is not intended for children.
Catalog
Diagram
1
Accessories
2
Installation
3
O4 Pro
3
O4
7
O3
9
Standard Version
12
AV
14
Controlling the C-20D
15
Private Protocol Control
15
Headtracker Direct Control
15
S.BUS / CRSF Control
15
PWM Control
15
MAVLink Control
15
Gimbal Modes
16
Gimbal Sensitivity
17
Carrier AHRS Fusion
17
Configuring, Calibrating & Firmware Upgrading
18
Connect the Gimbal
18
Parameter Configuration Basic Operation
19
Regular Modes
19
Gimbal Presets
19
(Headtracker direct, S.BUS/CRSF & PWM control)
19
Channel Mapping
20
(Headtracker direct, S.BUS/CRSF & MAVLink control)
20
Mounting Type
20
Tilt Protection (Pitch-lock & Horizon mode)
20
Parameter Tuning
21
Pitch Calibration
21
Calibrating & Firmware Upgrading
21
Appendix 1 Supported Cameras
22
Appendix 2 MAVLink Configuration
23
ArduPilot
23
PX4
23
Diagram
CVBS
GND
6
7V Out max0.2A
5
Nose Direction
C-20 User Manual
7V Out max0.2A
(Standard)
CVBS
(AV)
1 2 3
4
GND
Power In (7.4~26.4VDC) GND UART_Rx (0~3.3V) UART_Tx (0~3.3V) PWM1 / S.BUS / CRSF_Rx PWM2 PWM3 NC
The gimbal must share a common ground with the control signal transmitter.
1. Upgrade Port 2. Power Out / CVBS (BM02B-SRSS-TB) 3. Power-communication Port (BM08B-SRSS-TB) 4. Coaxial Cable Air Unit End (Standard) 5. Coaxial Cable Camera End (Standard) 6. Analog Camera Cable (MX1.25-3P, AV)
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Accessories
1
2
3
4
5
6
7
8
1. O4 Pro Lens Front Housing (O4 Pro) 2. O4 Pro Lens Rear Housing (O4 Pro) 3. O4 Pro lens Protection Ring (O4 Pro) 4. O4 Lens Mount (O4) 5. O4 Pressing Plate (O4) 6. O3 Lens Mount (O3) 7. O3 lens Protection Ring (O4 / O3) 8. Analog Camera Mount (AV)
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Installation O4 Pro
1. Remove the housing fixing screws of the camera (one on each side) and separate the front and rear housings of the camera. Do not separate the housings too far or may damage the camera.
2. Use the crowbar in the package to disconnect the coaxial cable from the camera and remove the rear housing. The coaxial cable and its connectors are vulnerable. Please be careful when disconnecting and connecting the cable.
3. Remove the four lens fixing screws inside the front housing and take the lens out.
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4. Install the lens protection ring on the front of the lens mount. 5. Fix the lens into the lens front housing with four M1.4 x L3mm screws.
The mounting direction of the lens in the lens mount is unique. Please note the correspondence between the lens locating posts and the locating holes inside the lens mount.
6. Connect the front and rear housing with four M1.4 x L2.5mm countersunk screws. Thermal Pad
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7. Connect the gimbal pre-built coaxial cable on the lens. The space is a narrow on this step. Please be careful not to pull the cable.
8. Fix the camera on the gimbal with three M1.4 x L5mm screws. Determine the mounting direction of the camera on the gimbal by usage scenario (gimbal upward / downward mounting). Avoid squeezing the cable when installing the camera. If the pitch motor of the gimbal spins unsmoothly or rebounds, it is generally caused by a tense coaxial cable. Please organize the cable and try again.
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9. Separate the top and bottom housing of the air unit, then use the crowbar to disconnect the coaxial cable from the air unit and remove it. Do not separate the housings too far or may damage the air unit.
10. Connect the coaxial cable from the gimbal to the air unit and assemble the air unit.
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O4
1. Use the crowbar in the package to disconnect the coaxial cable from the camera and remove the rear housing. The coaxial cable and its connectors are vulnerable. Please be careful when disconnecting and connecting the cable. There is glue on the connector for fixation. A heat gun can be used to heat the glue at 150 and remove it with tweezers after it is softened.
2. Install the lens protection ring on the front of the lens mount. 3. Connect the gimbal pre-built coaxial cable on the lens.
The space is a narrow on this step. Please be careful not to pull the cable. 4. Thread two M1.4 x L3mm screws through the pressing plate and fix the lens into the lens mount.
Thermal Pad
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5. Fix the camera on the gimbal with four M1.4 x L5mm screws. Determine the mounting direction of the camera on the gimbal by usage scenario (gimbal upward / downward mounting). Avoid squeezing the cable when installing the camera. If the pitch motor of the gimbal spins unsmoothly or rebounds, it is generally caused by a tense coaxial cable. Please organize the cable and try again.
6. Use the crowbar in the package to disconnect the coaxial cable from the air unit and remove the rear housing. The coaxial cable and its connectors are vulnerable. Please be careful when disconnecting and connecting the cable. There is glue on the connector for fixation. A heat gun can be used to heat the glue at 150 and remove it with tweezers after it is softened.
7. Connect the coaxial cable from the gimbal to the air unit.
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O3
1. Remove the housing fixing screws of the camera (one on each side) and separate the front and rear housings of the camera. Do not separate the housings too far or may damage the camera.
2. Use the crowbar in the package to disconnect the coaxial cable from the camera and remove the rear housing. The coaxial cable and its connectors are vulnerable. Please be careful when disconnecting and connecting the cable.
3. Remove the four lens fixing screws inside the front housing and take the lens out.
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4. Install the lens protection ring on the front of the lens mount. 5. Fix the lens into the lens mount with four M1.4 x L3mm screws.
The mounting direction of the lens in the lens mount is unique. Please note the correspondence between the lens locating posts and the locating holes inside the lens mount. 6. Connect the gimbal pre-built coaxial cable on the lens. The space is a narrow on this step. Please be careful not to pull the cable.
7. Fix the camera on the gimbal with four M1.4 x L5mm screws. Determine the mounting direction of the camera on the gimbal by usage scenario (gimbal upward / downward mounting). Avoid squeezing the cable when installing the camera. If the pitch motor of the gimbal spins unsmoothly or rebounds, it is generally caused by a tense coaxial cable. Please organize the cable and try again.
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8. Remove the cover of the coaxial cable on the bottom of the air unit, then use the crowbar to disconnect the cable from the air unit and remove it.
9. Connect the coaxial cable from the gimbal to the air unit and reinstall the cover back.
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Standard Version
Take Walksnail Moonlight kit as an example: 1. Loosen the four screws on the back of the camera and remove the rear
housing. 2. Use the crowbar in the package to disconnect the coaxial cable from the
camera and remove the cable. The coaxial cable and its connectors are vulnerable. Please be careful when disconnecting and connecting the cable.
3. Connect the gimbal pre-built coaxial cable on the lens. Please be careful not to pull the cable.
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4. Fix the camera on the gimbal with four M1.4 x L5mm screws. Determine the mounting direction of the camera on the gimbal by usage scenario (gimbal upward / downward mounting). Avoid squeezing the cable when installing the camera. If the pitch motor of the gimbal spins unsmoothly or rebounds, it is generally caused by a tense coaxial cable. Please organize the cable and try again.
5. Remove the cover of the coaxial cable on the top of the air unit, then use the crowbar to disconnect the cable from the camera and remove it.
6. Connect the coaxial cable from the gimbal to the air unit and reinstall the cover back.
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AV
1. Connect the gimbal pre-built analog camera cable on the camera. Please be careful not to pull the cable.
2. Fix the camera and the camera mount on the gimbal with two M1.4 x L10mm screws. Determine the mounting direction of the camera on the gimbal by usage scenario (gimbal upward / downward mounting). Avoid squeezing the cable when installing the camera. If the pitch motor of the gimbal spins unsmoothly or rebounds, it is generally caused by a tense cable. Please organize the cable and try again.
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Controlling the C-20D
The C-20D supports Headtracker direct / private protocol control, S.BUS / CRSF control, PWM control and MAVLink control, with the priority of the four control methods above decreasing in order.
Private Protocol Control
Please refer toGimbal Private Protocol .
Headtracker Direct Control
Please refer toHeadtracker User Manual .
S.BUS / CRSF Control
Connect the PWM1 in power-communication port to the S.BUS or CRSF_Tx of the receiver, which needs 4 channels to control gimbal mode, gimbal sensitivity, roll and pitch respectively. Channel mapping can be done in theGimbalConfig software.
PWM Control
The PWM1~PWM3 are channels to control gimbal mode, gimbal sensitivity and gimbal pitch respectively.
MAVLink Control
Connect the UART_Rx and UART_Tx in power-communication port to the Tx and Rx in a certain serial port of the autopilot respectively, which needs 4 channels to control gimbal mode, gimbal sensitivity, roll and pitch respectively. Channel mapping can be done in the GimbalConfig software.
Only ArduPilot firmware and PX4 firmware are supported currently. The MAVLink configuration are detailed in Appendix 2.
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Gimbal Modes
There are six operating modes of the C-20D as below: FPV Angle Control (FPVM-ANGL) The input control value to the gimbal corresponds to its rotation angle. When the input control value is 0, the gimbal’s pitch and roll axes follow the carrier’s movements with eliminating slight shaking.
PitchLock Angle Control (PLCK-ANGL) The input control value to the gimbal corresponds to its rotation angle. When the input control value is 0, the gimba’s pitch axis remains horizontal and its roll axis follows the carrier’s movements with eliminating slight shaking.
Horizon Angle Control (HORI-ANGL) The input control value to the gimbal corresponds to its rotation angle. When the input control value is 0, the gimbal’s pitch and roll axes remain horizontal.
Horizon Rate Control (HORI-RATE) The input control value to the gimbal corresponds to its rotation angular speed. When the input control value is 0, the gimbal’s pitch and roll axes keep current attitude.
When controlling the gimbal via Headtracker, angle control modes must be used.
For users employing the gimbal for non-head-tracking aerial filming, it is recommended to use rate control modes to achieve an optimal handling responsiveness.
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Return-to-Center (GOTO-ZERO) In this mode, the camera lens maintains horizontal forward orientation. The gimbal becomes non-controllable in this state. OrthoView (LOOK-DOWN) In this mode, the camera lens maintains vertically downward orientation. The gimbal becomes non-controllable in this state.
Gimbal Sensitivity
The higher the sensitivity is, the quicker the response of the gimbal to follow the motion of the carrier, but the less it eliminates the carrier’s wobble.
The gimbal sensitivity is vaild only in FPV mode.
Carrier AHRS Fusion
When subjected to a large horizontal overload, the gimbal’s attitude algorithm may exhibit certain deviations, resulting in an inclined attitude. To rectify this deviation, it is necessary to transmit valid carrier AHRS data (carrier GNSS positioning needs to be effective) to the gimbal via the MAVLink protocol. Carrier AHRS fusion is available in all control methods.
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Configuring, Calibrating & Firmware Upgrading
Configure the gimbal and upgrade firmware of the gimbal with the GimbalConfig software.
Ensure the driver of the Config Module is installed on the computer before configuring, calibrating or upgrading.
1 2 3
1. Gimbal Presets
2. Channel Mapping
3. Regular Modes
Connect the Gimbal
1. Connect the gimbal upgrading port and the computer with the J1.0 Config Module. Power up the gimbal.
2. Run the GimbalConfig software. Select the COM port corresponding to the Config Module. Click “Start Debug” and confirm the software and the gimbal being connected.
The Config Module is sold separately. For some brands of dual Type-C cables, there may be cases where the computer cannot recognize the Config Module. Please try replacing it with a Type-A to Type-C cable.
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Parameter Configuration Basic Operation
After the gimbal is connected to the GimbalConfig software, the software will automatically download the parameter from the gimbal, or you can click “Download Param” to perform the download operation. Click “Save Param” to save the current displayed parameter as a local file. Click “Open Param” to read a locally saved parameter file. After selecting a new option in the drop-down box, the parameter will be automatically uploaded to the gimbal and take effect. After entering a new parameter in the parameter frame, press Enter key or click “Upload Param” to upload the parameter. After the parameter is uploaded, click “Save Param To Flash” to finalize it into the gimbal.
If not click “Save Param To Flash” after uploading parameters, the uploaded parameters will be lost when the gimbal loses power.
Regular Modes
Users can select three work modes from the gimbal’s various options to serve as their regular modes (M0 / M1 / M2).
Gimbal Presets (Headtracker direct, S.BUS/CRSF & PWM control)
The gimbal works in accordance with the preset values when there is no signal input or no mapped channel assigned. After the signal input is restored, the gimbal exits the preset state. The gimbal presets are invalid in MAVLink control. Preset gimbal mode: Users can choose one work mode from the regular modes (M0 / M1 / M2) as the preset mode. Preset gimbal sensitivity: setting range -1.0~1.0, with a resolution of 0.1. Preset roll, pitch and yaw angle: setting range -180° ~180° , with a resolution of 1° .
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The actual effective preset angles are based on the maximum rotation range of the gimbal. If you want to always use the preset values for some channels, map the corresponding channels to NULL.
Channel Mapping (Headtracker direct, S.BUS/CRSF & MAVLink control)
Select the channels corresponding to gimbal mode, gimbal sensitivity, roll, pitch and yaw respectively. For Headtracker direct control (through datalink or Air Unit), all channels should be mapped to CH01.
Mounting Type
The mounting type of the gimbal is AUTO by default, and the gimbal will automatically switch to DOWN/UP mode according to its attitude at power-on. The mounting type can also be manually set as DOWN or UP mode.
For tail-sitter VTOL aircrafts, it should place the fuselage in a level flight attitude and power up, or manually set the mounting type of the gimbal. After the mounting type is set manually, make sure that the actual mounting type is consistent with the setting, otherwise the gimbal will enter the protection state.
Tilt Protection (Pitch-lock & Horizon mode)
When the tilt of the mounting plane of the gimbal exceeds the protect angle, the gimbal will enter the protection state, at this time the gimbal will be neutralized and uncontrollable. When the tilt of the mounting plane is smaller than the protect angle, the gimbal will automatically exit the protection state. Tilt protection is effective in Pitch-lock mode and Horizon mode, not in FPV mode.
The protection angle can be modified according to the actual use. The setting range is 0° ~90° with a resolution of 1° . 15° means disabling the tilt protection.
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After disabling the tilt protection, the gimbal may work abnormally when the attitude angle of the carrier is large.
Parameter Tuning
For cameras with larger moment of inertia, mounting them on the gimbal may result in gimbal shaking. In such cases, increasing the gain value can enhance stabilization effects.
It is strongly recommended to use the default gain parameters if unnecessary.
Pitch Calibration
In FPV mode, the gimbal’s pitch center may exhibit a slight deviation. This parameter allows fine-tuning of the pitch zero point specifically for FPV mode. The adjustable range is -10° ~+10° with a resolution of 0.1° .
Calibrating & Firmware Upgrading
If the attitude of the gimbal tilts or drifting slowing when no control signal input, it is necessary to calibrate the gimbal. 1. To calibrate the gimbal. Keep the gimbal static. Click “Gyro Calibration” and wait for the calibration to complete. 2. To upgrade the firmware. Click “Open Firmware”. Select the firmware file. Click “Start Upgrade” and wait for the upgrade to complete.
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Appendix 1 Supported Cameras
Walksnail Moonlight Kit Walksnail Avatar HD Kit V2 (Dual Antannas Version) Walksnail Avatar HD Pro Kit (Dual Antannas Version) Walksnail Avatar HD Pro Kit Walksnail Avatar HD Kit V2 Standard Version CADDXFPV Polar Starlight Vista Kit CADDXFPV Nebula Pro Vista Kit RunCam Link Phoenix HD Kit RunCam Link Wasp Kit RunCam Link Night Eagle Kit
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Appendix 2 MAVLink Configuration ArduPilot
C-20 User Manual
SERIAL1 SERIAL1_BAUD SERIAL1_OPTIONS SERIAL1_PROTOCOL SR1 SR1_ADSB SR1_EXIT_STAT SR1_EXTRA1 SR1_EXTRA2 SR1_EXTRA3 SR1_PARAMS SR1_POSITION SR1_RAW_CTRL SR1_RAW_SENS SR1_RC_CHAN
115 1024 2
0 Hz 0 Hz 0 Hz 0 Hz 0 Hz 0 Hz 0 Hz 0 Hz 0 Hz 0 Hz
Serial port number can be changed according to the actual situation.
PX4
MAVLink MAV_1_CONFIG MAV_1_MODE MAV_1_RATE Serial SER_TEL2_BAUD
TELEM2 Custom / Gimbal 115200 B/s
115200 8N1
The MAV_1_MODE is recommended as Custom.
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Documents / Resources
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