Pixhawk Adapter Board

The Pixhawk adapter board is used to break out the Skynode flight control interfaces on J3 and J4 to connectors and pinouts compatible to the Pixhawk-standard.

The voltage levels for all signals brought out from the FMU to the Pixhawk Adapter Board are either 5V or 3.3V compliant. Refer to the table below to check the voltage levels of specific pins. Exceeding these voltages will permanently damage the Flight Management Unit inside Skynode.

Connector Locations

1MB

Pixhawk Adapter Board.stl

Schematic

169KB

Pixhawk-Adapter-Board_RC05.pdf

pdf

181KB

Pixhawk-Adapter-Board_RC06.pdf

pdf

Take a look at the Skynode Harwdare Revision 11 release notes for details about the changes.

Connectors

ID	Name	Connector	Description
J11	Primary	Molex Pico-Clasp 5015714007	Connect to Skynode Primary (J4)
J12	Telem 1	JST GH 6-pin SM06B-GHS-TB
J13	GPS 1	JST GH 10-pin SM10B-GHS-TB (until rev 5 included) JST GH 11-pin SM11B-GHS-TB (from rev 6 included)	Primary GPS with external compass, safety switch and led
J14	CAN 1	JST GH 4-pin SM04B-GHS-TB
J15	FMU	Pin Header TSW-108-08-G-T-RA	PWM channels from FMU, input capable
J16	SBUS RC	JST GH 3-pin SM03B-GHS-TB	SBUS protocol RC input
J18	I2C 1	JST GH 4-pin SM04B-GHS-TB

ID	Name	Connector	Description
J21	Secondary	Molex Pico-Claspre team is looki 5015714007	Connect to Skynode Secondary (J3)
J22	SBUS OUT	JST GH 3-pin SM03B-GHS-TB	SBUS output
J23	GPS 2	JST GH 6-pin SM06B-GHS-TB	Redundant GPS
J24	SPI	JST GH 11-pin SM11B-GHS-TB
J25	IO	Pin Header TSW-108-08-G-T-RA	PWM channels from IO
J26	Telem 3	JST GH 6-pin SM06B-GHS-TB
J27	CAN 2	JST GH 4-pin SM04B-GHS-TB
J28	I2C 2	JST GH 4-pin SM04B-GHS-TB

Pinouts

Telem 1 (J12)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_HIPOWER		5V	5V supply for peripherals, max. 1.0A (fused)
2	UART7_TX	OUT	3.3V	Telem 1 TX
3	UART7_RX	IN	3.3V	Telem 1 RX
4	UART7_CTS	IN	3.3V	Telem 1 CTS
5	UART7_RTS	OUT	3.3V	Telem 1 RTS
6	GND			Ground

GPS 1(J13)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_CAN1_GPS1		5V	5V supply for primary GPS and CAN interface
2	USART1_TX	OUT	3.3V	GPS 1 TX
3	USART1_RX	IN	3.3V	GPS 1 RX
4	I2C1_SCL	I/O	3.3V	I2C SCL for external magnetometer
5	I2C1_SDA	I/O	3.3V	I2C SDA for external magnetometer
6	GPS_PPS	IN	3.3V	PPS signal from GPS module
7	FMU_IO_SAFETY_SWITCH_IN	IN	3.3V	Safety switch state input
8	FMU_IO_nSAFETY_SWITCH_LED_OUT	OUT	3.3V	Safety switch led output
9	FMU_VDD_3V3	OUT	3.3V	3.3V supply for peripherals, max 50mA
10	BUZZER_1_INV	OUT		Buzzer output (open drain)
11	GND			Ground

I2C lines are pulled up with 1kΩ in Skynode. External pull up resistors shall not be added.

The highlighted pin 6 was added in rev 6 of the Pixhawk Adapter Board, to ensure compatibility with the PX4 F9P GPS module. For backwards compatibility with the Freefly RTK GPS module, a custom cable needs to be made.

CAN 1 (J14)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_CAN1_GPS1		5V	5V supply for primary GPS and CAN interface
2	CAN1_P	I/O	5V	FMU CAN 1
3	CAN1_N	I/O	5V	FMU CAN 1
6	GND			Ground

CAN bus termination on Skynode changed in RC11. Prior to rev 11, Skynode has a 120Ω bus termination resistor inside, with no CAN termination on the Pixhawk Adapter Boards (until rev 5 included). This configuration assumed that Skynode was at the end of the bus. Rev 11 and onwards has the 120Ω bus termination resistor on the Pixhawk Adapter Boards (from rev 6 included), without built-in termination inside of Skynode. When designing a wire harness instead of using the Pixhawk Adapter Boards, usage of 120Ω termination resistors at both ends of the bus is mandatory, following ISO 11898..

FMU - ESC and Servo (J15)

Pin	Name	Dir	Lvl	PWM/ OneShot	DShot	Shared with PPB
1	FMU_CH1	I/O	3.3V	Yes	Yes
2	FMU_CH2	I/O	3.3V	Yes	Yes
3	FMU_CH3	I/O	3.3V	Yes	Yes
4	FMU_CH4	I/O	3.3V	Yes	Yes
5	FMU_CH5	I/O	3.3V	Yes	Yes
6	FMU_CH6	I/O	3.3V	Yes	Yes
7	FMU_CH7	I/O	3.3V	Yes		Yes
8	FMU_CH8	I/O	3.3V	Yes		Yes

SBUS RC (J16)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_SBUS_RC		5V	5V supply for RC receiver, max 250mA
2	IO_SBUS_INPUT	IN	3.3V	SBUS protocol RC input
3	GND			Ground

I2C 1 (J18)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_CAN1_GPS1		5V	5V supply for primary GPS and CAN interface
2	I2C1_SCL	I/O	3.3V	I2C SCL for external peripherals
3	I2C1_SDA	I/O	3.3V	I2C SDA for external peripherals
6	GND			Ground

I2C lines are pulled up with 1kΩ in Skynode. External pull up resistors shall not be added.

SBUS OUT (J22)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_SBUS_RC			Not connected
2	IO_SBUS_OUTPUT	OUT	3.3V	SBUS protocol output
3	GND			Ground

GPS 2 (J23)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_PERIPH		5V	5V supply for peripherals
2	USART8_TX	OUT	3.3V	GPS 2 TX
3	USART8_RX	IN	3.3V	GPS 2 RX
4	I2C2_SCL	I/O	3.3V	I2C SCL for external magnetometer
5	I2C2_SDA	I/O	3.3V	I2C SDA for external magnetometer
6	GND			Ground

I2C lines are pulled up with 1kΩ in Skynode. External pull up resistors shall not be added.

SPI (J24)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_PERIPH
2	SPI6_SCK	OUT	3.3V	SPI Clock
3	SPI6_MISO	IN	3.3V	SPI MISO
4	SPI6_MOSI	OUT	3.3V	SPI MOSI
5	SPI6_nCS1	OUT	3.3V	Chip select 1
6	NC
7	SPI6_nSYNC	OUT	3.3V	Sync signal
8	SPI6_DRDY1	IN	3.3V	Data ready 1
9	NC
10	SPI6_nRESET	OUT	3.3V	Reset
11	GND

IO - ESC and Servo (J25)

Pin	Name	Dir	Lvl	PWM/ OneShot	DShot	Shared with PPB
1	IO_CH1	OUT	3.3V	Yes
2	IO_CH2	OUT	3.3V	Yes
3	IO_CH3	OUT	3.3V	Yes
4	IO_CH4	OUT	3.3V	Yes
5	IO_CH5	OUT	3.3V	Yes
6	IO_CH6	OUT	3.3V	Yes
7	IO_CH7	OUT	3.3V	Yes
8	IO_CH8	OUT	3.3V	Yes

Telem 3 (J26)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_PERIPH		5V	5V supply for peripherals
2	USART2_TX	OUT	3.3V	Telem 3 TX
3	USART2_RX	IN	3.3V	Telem 3 RX
4	NC
5	NC
6	GND			Ground

CAN 2 (J27)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_PERIPH		5V	5V supply for peripherals
2	CAN2_P	I/O	5V	FMU CAN 2
3	CAN2_N	I/O	5V	FMU CAN 2
6	GND			Ground

CAN bus termination on Skynode changed in RC11. Prior to rev 11, Skynode has a 120Ω bus termination resistor inside, with no CAN termination on the Pixhawk Adapter Boards (until rev 5 included). This configuration assumed that Skynode was at the end of the bus. Rev 11 and onwards has the 120Ω bus termination resistor on the Pixhawk Adapter Boards (from rev 6 included), without built-in termination inside of Skynode. When designing a wire harness instead of using the Pixhawk Adapter Boards, usage of 120Ω termination resistors at both ends of the bus is mandatory, following ISO 11898.

I2C 2 (J28)

Pin	Name	Dir	Lvl	Function
1	VDD_5V_PERIPH		5V	5V supply for peripherals
2	I2C2_SCL	I/O	3.3V	I2C SCL for external peripherals
3	I2C2_SDA	I/O	3.3V	I2C SDA for external peripherals
6	GND			Ground

I2C lines are pulled up with 1kΩ in Skynode. External pull up resistors shall not be added.