8-Channel PWM or Servo FeatherWing Add-on For All Feather Boards — pinout, I²C address, specs

Pinout

54 pads, as the vendor numbers them.

#	Name	Function	Signals
1	WAKE	Header pad where the Feather's WAKE pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
2	D1	Header pad where the Feather's D1 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
3	D0	Header pad where the Feather's D0 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
4	MISO	Header pad where the Feather's MISO pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
5	MOSI	Header pad where the Feather's MOSI pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
6	SCK	Header pad where the Feather's SCK pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
7	A5	Header pad where the Feather's A5 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
8	A4	Header pad where the Feather's A4 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
9	A3	Header pad where the Feather's A3 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
10	A2	Header pad where the Feather's A2 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
11	A1	Header pad where the Feather's A1 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
12	A0	Header pad where the Feather's A0 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
13	GND	3.3 V logic ground, taken from the Feather's GND pin	ground
14	AREF	Header pad where the Feather's AREF pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
15	3V	Logic supply for the PCA9685 from the Feather's 3.3 V regulator; it also sets the I2C and PWM logic level	3.3 V supply, input
16	RST	Tied to the on-board reset button (fab file SW1) - pressing it pulls the Feather's RESET low	reset, input
17	BAT	Header pad where the Feather's BAT pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
18	EN	Header pad where the Feather's EN pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
19	USB	Header pad where the Feather's USB pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
20	D13	Header pad where the Feather's D13 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
21	D12	Header pad where the Feather's D12 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
22	D11	Header pad where the Feather's D11 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
23	D10	Header pad where the Feather's D10 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
24	D9	Header pad where the Feather's D9 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
25	D6	Header pad where the Feather's D6 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
26	D5	Header pad where the Feather's D5 pin sits; nothing on this wing connects to it, so the pad is mechanical only	Feather header pass-through, not connected on this board
27	SCL	I2C clock, 10 kOhm pull-up to 3.3 V on the board	I2C SCL, input
28	SDA	I2C data, 10 kOhm pull-up to 3.3 V on the board	I2C SDA, bidirectional
29	PWM0	Servo/PWM port 0, signal pin - fab file JP2 pad 1, one of the 3x4 0.1in headers	PWM output 0, 220 ohm series resistor on the output
30	V+ 0	Servo/PWM port 0, V+ pin - fab file JP2 pad 2, one of the 3x4 0.1in headers	servo power
31	GND 0	Servo/PWM port 0, GND pin - fab file JP2 pad 3, one of the 3x4 0.1in headers	ground
32	PWM1	Servo/PWM port 1, signal pin - fab file JP2 pad 4, one of the 3x4 0.1in headers	PWM output 1, 220 ohm series resistor on the output
33	V+ 1	Servo/PWM port 1, V+ pin - fab file JP2 pad 5, one of the 3x4 0.1in headers	servo power
34	GND 1	Servo/PWM port 1, GND pin - fab file JP2 pad 6, one of the 3x4 0.1in headers	ground
35	PWM2	Servo/PWM port 2, signal pin - fab file JP2 pad 7, one of the 3x4 0.1in headers	PWM output 2, 220 ohm series resistor on the output
36	V+ 2	Servo/PWM port 2, V+ pin - fab file JP2 pad 8, one of the 3x4 0.1in headers	servo power
37	GND 2	Servo/PWM port 2, GND pin - fab file JP2 pad 9, one of the 3x4 0.1in headers	ground
38	PWM3	Servo/PWM port 3, signal pin - fab file JP2 pad 10, one of the 3x4 0.1in headers	PWM output 3, 220 ohm series resistor on the output
39	V+ 3	Servo/PWM port 3, V+ pin - fab file JP2 pad 11, one of the 3x4 0.1in headers	servo power
40	GND 3	Servo/PWM port 3, GND pin - fab file JP2 pad 12, one of the 3x4 0.1in headers	ground
41	PWM7	Servo/PWM port 7, signal pin - fab file JP1 pad 1, one of the 3x4 0.1in headers	PWM output 7, 220 ohm series resistor on the output
42	V+ 7	Servo/PWM port 7, V+ pin - fab file JP1 pad 2, one of the 3x4 0.1in headers	servo power
43	GND 7	Servo/PWM port 7, GND pin - fab file JP1 pad 3, one of the 3x4 0.1in headers	ground
44	PWM6	Servo/PWM port 6, signal pin - fab file JP1 pad 4, one of the 3x4 0.1in headers	PWM output 6, 220 ohm series resistor on the output
45	V+ 6	Servo/PWM port 6, V+ pin - fab file JP1 pad 5, one of the 3x4 0.1in headers	servo power
46	GND 6	Servo/PWM port 6, GND pin - fab file JP1 pad 6, one of the 3x4 0.1in headers	ground
47	PWM5	Servo/PWM port 5, signal pin - fab file JP1 pad 7, one of the 3x4 0.1in headers	PWM output 5, 220 ohm series resistor on the output
48	V+ 5	Servo/PWM port 5, V+ pin - fab file JP1 pad 8, one of the 3x4 0.1in headers	servo power
49	GND 5	Servo/PWM port 5, GND pin - fab file JP1 pad 9, one of the 3x4 0.1in headers	ground
50	PWM4	Servo/PWM port 4, signal pin - fab file JP1 pad 10, one of the 3x4 0.1in headers	PWM output 4, 220 ohm series resistor on the output
51	V+ 4	Servo/PWM port 4, V+ pin - fab file JP1 pad 11, one of the 3x4 0.1in headers	servo power
52	GND 4	Servo/PWM port 4, GND pin - fab file JP1 pad 12, one of the 3x4 0.1in headers	ground
53	SERVO V+ IN	Servo power terminal (fab file J1) pad 1, through the reverse-polarity P-FET (Q1) onto the 5.0V rail; silk prints "V+" and "V+ 6V Max"	servo power input, power
54	SERVO GND	Servo power terminal pad 2, on the GND net; silk prints "GND" and a minus sign	servo power return, ground

Buses

Bus	Signals	Pins	Voltage	Note
I2C ×1	SDA, SCL	SDA, SCL

I²C / bus addresses

Address	Bus	Device	Note
0x40	I2C	PCA9685 16-channel 12-bit PWM driver	7-bit default with all six jumpers (SJ_A0-SJ_A5, on the bottom) open. Closed jumpers add binary weights to 0x40, so the range is 0x40-0x7F. The chip's fixed all-call address 0x70 is what A4 and A5 bridged together produce, so leave at least one of those two open unless all-call is wanted.

Power

Input	Two supplies: 3.3 V logic from the Feather through the header, and a separate 5-6 V supply for the servos on the 2-pin terminal block (fab file J1, silk "V+ 6V Max")
Input range	Servo rail 5-6 V DC per Adafruit's guide; the silkscreen caps it at 6 V

The servo rail is not derived from the Feather at all: it arrives on J1, passes a reverse-polarity P-channel MOSFET (fab file Q1, AON7401) and becomes the fab net named 5.0V, which feeds every port's V+ pin and the 5VOK LED (green, with a 470 ohm resistor). If 5VOK is dark, V+ is dead and no servo will move. Adafruit warns against powering servos from the Feather's USB pin at all because of brownouts, and sizes supplies as a 5 V 2 A brick for about 4 servos or 5 V 10 A for up to 16 - several high-torque servos pull more than 1 A each. There is a footprint for a large electrolytic on the V+ rail (fab file C2, 3.5 mm can) for exactly that reason. Adafruit publishes no current figure for the wing itself.

Notes

Pin numbers 1-28 are the fab file's own pad numbers: 1-16 = JP3 (the 1x16 header, WAKE at pad 1 through RESET at pad 16), 17-28 = JP4 (the 1x12 header, BAT at pad 1 through SDA at pad 12). As on the motor wing, only GND, 3V, RST, SCL and SDA carry a wing circuit and the rest are through-holes for the Feather's pins; they are listed because the land pattern has them. Pins 29-52 are the eight servo ports, three pins each: in the fab file port 0 sits at the highest y of the left 3x4 header and port 3 at its lowest, while the right header is the other way up - port 7 at the highest y, port 4 at the lowest. Adafruit's guide lists a port's three pins as GND, V+, Signal; the fab file's pad order inside a port is signal, V+, GND, so the net, not the pad position, is what says which pin is which. Outputs go through 220 ohm series resistors (fab file R11/R13) taken from Adafruit's own note: that both protects the pins and lets an LED be driven directly. The PCA9685's OE pin is tied to ground through a 10 kOhm resistor (fab file R7), so the outputs are always enabled - there is no external output-enable pin to gate the PWM. Silkscreen prints the PWM range as "Freq: 40-1000Hz". All eight channels are 12-bit (4096 steps); Adafruit describes the board as 8 x 12-bit PWM. Dimensions 50.8 x 22.9 x 1.6 mm, 3.9 g; the fab file's outline measures 50.80 x 22.86 mm, which agrees. Stacking needs 3x4 right-angle headers (product 816) as well as stacking headers, or the servo plugs foul the board above.

Provenance

Every figure on this page was read from the 3 sources below and last checked on Oct 19, 2026.