HDP20 pin assignment

Connect A (forward)

Taxi lights

• 3 size 16 pins, pos (4), neg (5), shld (1)

IBBS battery (shared with B connector)

• 1 size 16 pin (13A rating) - main aircraft bus (3 20AWG wires from DB15 wires condensed into 1 pin) (6)
• 1 size 16 pin (13A rating) - gnd (3 20AWG wires from DB15 wires condensed into 1 pin) (34)
• 4 size 20 pins, charge/sense, low voltage warning LED, batt info volt meter, backup power master

Tail ADS B-In

• 2 size 20 pins, serial rx, serial tx

Transponder

• 2 size 20 pins, serial rx, serial tx

Tail ADS B-in/Transponder

• 2 size 20 pins, pwr, gnd

Stick

• 5 size 20 pins, lh trim up, lh trim down, rh tirm up, rh trim down, stick gnd (omit AP disconnect)

Servos

• 2 size 20 pins, pos, neg

Magnetometer

• 3 size 20 pins, pos1, pos2, gnd, +12V auxillary maybe

Servos/Magnetometer

• 4 size 20 pins, net 1a, net 1b, net 2a, net 2b,

USB

• 3 size 20 pins, pos, neg, shld

Overhead lights

• 3 size 20 pins, white gnd, red gnd, pos

Trim

• 2 size 20 pins, red, green

Flap control

• 5 size 20 pins, pos, gnd, flap up, flap down, airspeed

ELT beacon

• 5 size 20 pins, gnd, shld, elt rx, rmt sw, ext on

A subtotal

37 size 20, 5 size 16

4 keying pins

Connect B (aft)

IBBS battery

• 1 size 16 pin (13A rating) - backup power output (4 20AWG wires from DB15 condensed into 1 pin) (34)
• on the other connector this is connected to GND so the consequence of swapping connectors will be a blown fuse on the output of the IBBS

Landing lights

• 4 size 16 pins, lh pos (4), rh pos (6), neg (5) , shld (1)

Nav/strobe lights

• 4 size 20 pins, nav pos, strb pos, neg, shld

GPS2020

• 4 size 20 pins, plus8v, gnd, serial rx, serial tx

Left wing OAT

• 3 size 20 pins, signal, pwr, gnd

Flarm fusion

• 3 size 20 pins, serial tx, pwr, gnd

COM radio

• 5 size 20 pins, gnd, pwr, enable, data rx, data tx

Magnetos

• 3 size 20 pins, left, right, common shield

Start contactor

• 1 size 20 pin

Master contactor

• 1 size 20 pin

Intercom

• 6 size 20 pins, audio left, audio right, audio gnd, dim, pwr, gnd

Wing OAT

• 2 size 20 pins

B subtotal

37 size 20, 5 size 16

4 size 20 keying pins

Idea: assign the gnd and positive wires on each connector to the same respective pins, so if I need to dispense with the keying pins at some stage I can build in a resilience to accidently swapping the connectors