Electrical Interfaces
Expansion Ports
External Com Expansion
The external communications expansion port is located between booms 1 and 2 on the ALTA.
External Com Expansion (RID)
GH-6 Pin | GH-4 Pin |
Telemetry Ports
TELEM 1:
By default, TELEM 1 is used as the telemetry connection for the FRX Pro radio. It is fully configurable for what is sent, baud rate, etc. This port is turned on by default and the RAM usage fully accounted for in the Alta X’s design.
TELEM 2:
This is the telemetry connector that is inside the drone. It is also fully configurable. It is shared with the WiFi module so WiFi must be disabled for TELEM 2 to be used. The use of TELEM 2 requires additional RAM usage. As the RAM availability of the Alta X is limited, use of TELEM 2 may lead to issues caused by insufficient memory. (see SB006)
The RID capable IO module comes with a “breakout” for TELEM2 to grant easier access to the TELEM 2 port. Pilots flying with Alta Xs that have been manufactured since the March 18th, 2024 release of the RID module or, “standard module users,” will have access to this telemetry port by default. Pilots that have installed the RID IO module themselves or, “broadcast module users,” will need to install the cable connecting the breakout TELEM 2 port to the Alta X’s inner TELEM 2 port.
“Broadcast module” users can reach out to Freefly Support for more information on purchasing the cable needed for use of the breakout TELEM 2 port.
Installing the cable that connects the breakout TELEM 2 port to the inner TELEM 2 port does not change your “broadcast” module into a “standard” module.
Installing the cable that connects the breakout TELEM 2 port to the inner TELEM 2 port requires opening up the chassis of the Alta X. Performing this installation is done at the user’s discretion.
AUX UART:
The AUX UART port is a hardcoded MAVLink stream that controls Alta X’s onboard system functions such as the lights, video OSD, and RID. AUX UART is connected internally as TELEM4, however, attempting to configure TELEM 4 is not advised as any changes to how AUX UART communicates will break the internal operation of the drone. AUX UART is fixed at a 57600 baud rate and has a fixed set of MAVLink messages.
5V External Power
The external expansion connector port 5V power is provided by a dedicated 5V 3A current limited power supply separate of the redundant 5V power supplies for the flight controller. Each output on the external expansion connectors is protected by a 1.1A hold 2.2A trip PTC (Part number 0ZCG0110FF2C). The sum of the power supplying the following components must be less than 3A:
Motor boom LEDs (approx 1A during flight with 2x red and 2x green LEDs)
Long range radio if not powered via other means (FRX Pro is powered by 12V)
All internal CANbus peripherals on CAN expansion connectors
All external UART, I2C, and CANbus connectors
UART Port - GH-6 Pin
MAVLink serial communications at 57600b 8-N-1
Pin | Signal | Voltage (V) |
1 | VCC | +5V |
2 | TX (Out) | +3V |
3 | RX (In) | +3V |
4 | CTS (In) | +3V |
5 | RTS (Out) | +3V |
6 | GND | GND |
GPS2 Port - GH-6 Pin
Nuttx console output at 57600b 8-N-1.
Pin | Signal | Voltage (V) |
1 | VCC | +5V |
2 | TX (Out) | +3V |
3 | RX (In) | +3V |
4 | I2C1 SCL | +3V |
5 | I2C1 SDA | +3V |
6 | GND | GND |
CAN Ports - GH-4 Pin
Peripheral CANbus for future expansion.
Pin | Signal | Voltage (V) |
1 | VCC | +5V |
2 | CAN_H | +5V |
3 | CAN_L | +5V |
4 | GND | GND |
WARNING: Internal Long Range RF CAN is 12V VCC, do not use!
I2C Ports - GH-4 Pin
I2C bus for future expansion
Pin | Signal | Voltage (V) |
1 | VCC | +5V |
2 | I2C1 SCL | +3V |
3 | I2C1 SDA | +3V |
4 | GND | GND |
Power Expansion
The power expansion port is located between booms 1 and 2 on the ALTA; it contains three externally-facing and two internally-facing direct battery connected power expansion connectors with female socket pin XT-30 type connectors. Each external output is protected by a 10A automotive mini blade type fuse. The replacement fuse part number is 0297010.WXNV.
The system and fuses are sized to supply 10A or less continuously on each external port simultaneously; the internal connectors share the same fuse with the external connector J1. Please note that the output voltage will vary with system battery voltage as the battery discharges.
Use of any other size fuse could cause the aircraft to crash if shorted.
FPV Cable Pinout
Cable FPV TX
Every Alta X comes with a cable pre-installed to attach the FPV video transmission system. Freefly provides this FPV system and the appropriate cable to attach the transmitter to the aircraft cable, but if the customer wants to install their own FPV transmitter, please use the pinout below for wiring guidance. Also see note below pinout for camera-specific guidance.
Connector Pinout (DF11-6DEP-2C) | Designation | Color |
1 | 12V | RED |
2 | GND | BLACK |
3 | 5V | PURPLE |
4 | 5V-Pass-Thru | GREY |
5 | VID-IN | YELLOW |
6 | VID-OUT | ORANGE |
Note: The Freefly-provided FPV system powers the camera via the 5V-passthrough at the VTX. If the customer wants to install their own VTX that does not provide a 5v-passthrough, it is necessary to power the camera directly from the 5V pin (Pin 3). This can be done by moving the pin on the camera cable from pin 4 to pin 3.
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