Partlist

partlist.txt

C2		100nF (on bottom!)
IC1		4066N (on bottom!)
C1		470uF
R1		1k
D1 		1N4004
R2,R3,R4	100R
ZENER		5.1V
R6		6k8
R5		3k3
HU		2x5 header
12V		1x2 header
NANO		Arduino Nano (USB port to the PCB edge)
BT		Bluetooth Module CSR8645 with 12V regulator (regulator "on top")

Careful with the 12V header, space is a bit tight to the HU header.

Pin Out HU Header
Numbering is non-default (sorry):
      ___
[1] 2 =3= 4  5
 6  7  8  9 10

PCB		MELBUS
 1 Gnd		Shield
 2 Audio Gnd	2
 3 Busy		5
 4 Audio Left	6
 5 NC		-
 6 NC		-
 7 V_Run (12V)	3 (optional)
 8 Clock	1
 9 Data		4
10 Audio Right	7

The 12V pin header:
The marked pin (outer pin) is connected to the Arduino Nano and the bluetooth module.
The unmarked inner pin is connected to V_Run.

Either connect the outer pin to an external 12V source (e.g. cigarette ligher), or connect the inner to the outer pin.