Build a Zynthian

1 How to build a Zynthian (Prototype-3)

Manual is currently in development! (20150406)

1.1 Disclaimer

No guarantee for nothing. You do everything on your own risk!

1.2 Prerequisites

Want to join the Zynthian community? No problem! Building your own Zynthian is not very difficult. If you get trouble you can contact us at support@zynthian.org or via the blog http://blog.zynthian.org.

1.2.1 Required competences

For building the hardware you should have the following competences:

• Soldering
• Basic understanding of reading electronic circuit diagrams
• Enjoyment of work with electronic hardware and parts

1.2.2 Tools

• Screw drivers
• Soldering iron
• Tin-solder
• Side cutter
• Magnifiying glass

1.3 Hardware

1.3.1 Bill of Material

Here is a list of the hardware components you will need to build the Zynthian device. I also provided links to my suppliers and the prices I paid for the components in February 2016. I bought everything from Germany, so all descriptions are in German and prices are in EUR. If you live in another country maybe you'll get things even cheaper.

No	Shipper	Order no.	Description	Pieces	Price per piece [€]
1	http://www.reichelt.de	1N 4148	Planar Epitaxial Schaltdiode, DO35, 100V, 0,15A	1	0,04
2	http://www.reichelt.de	6N 138	OPTOKOPPLER	1	0,58
3	http://www.reichelt.de	RASPBERRY PI 2	Raspberry Pi 2, 4x 900 MHz, 1 GB RAM	1	37,50
4	http://www.reichelt.de	RPI HB DAC+ RCA	HiFiBerry DAC+ RCA, Raspberry Pi Shield	1	35,90
5	http://www.reichelt.de	1/4W 220	Kohleschichtwiderstand 1/4W, 5%, 220 Ohm	1	0,10
6	http://www.reichelt.de	1/4W 1,0K	Kohleschichtwiderstand 1/4W, 5%, 1,0 K-Ohm	1	0,10
7	http://www.reichelt.de	1/4W 10K	Kohleschichtwiderstand 1/4W, 5%, 10 K-Ohm	1	0,10
8	http://www.reichelt.de	MKS-02 100N	WIMA Folienkondensator, Rm 2,5mm 100nF	4	0,15
9	http://www.reichelt.de	GS 18P	IC-Sockel, 18-polig, superflach, gedreht, vergold.	1	0,32
10	http://www.reichelt.de	GS 8P	IC-Sockel, 8-polig, superflach, gedreht, vergold.	1	0,19
11	http://www.reichelt.de	SL 2X25G 2,54	2x25pol.-Stiftleiste, gerade, RM 2,54	1	0,24
12	http://www.reichelt.de	MAB 5S	DIN-Buchse, 5-polig	1	0,24
13 (OPTIONAL)	http://www.reichelt.de	NTA 176	6,3 Mono-Klinken-Bu. auf Cinch-St.	2	0,35
14	http://www.reichelt.de	NT MUSB 2 SW	Micro-USB Steckernetzteil, schwarz, 5 V, 2 A	1	8,40
15	http://www.segor.de	MCP23008-E/P	MCP23008 8 port I2C-GPIO extender	1	2,10
16	http://www.amazon.de	Adafruit PiTFT 2.8"	Adafruit PiTFT Touchscreen Display, 2,8 Zoll, für Raspberry Pi Computer	1	32,00
17	http://www.ebay.de	12mm Rotary Encoder Switch	Rotary Encoder with switch, 20 steps	4	0,60
18	http://www.ebay.de	Poti knob	Poti knob for Rotary encoder (Pos. 17)	4	1,50
19	http://blog.zynthian.org	Encoder PCB	PCB for encoders	2	10,00
20	http://blog.zynthian.org	2in1 PCB	PCB for MIDI and GPIO extension	1	10,00
21	http://blog.zynthian.org	Main Bus Ribbon Cable	Raspberry Main Bus Ribbon Cable	1	20,00
22	http://blog.zynthian.org	Mini-ribbon cable	Mini-ribbon cable (6 pin female connector to 6 female jumper connectors	3	3,00
23	http://www.saturn.de	SD card	Samsung 32GB SD card	1	14,00
24	-	Short connector cables	Connector cables pin-female/pin-female for MIDI and external GPIO connector from 2in1 board	4	??,??
25	-	Multi-pin connector	1x40pol.-Stiftleiste, gerade, RM 2,54	1	??,??

Notes:

• Pos. 19-22 were ordered directly from Zynthian.
• There is no case in this BoM - You have to build your own.
• Total price was 200,27 € (plus shipping).

1.4 Assembly and Soldering of the PCBs

1.4.1 Step 1: 2in1 board

1.4.1.1 You need:

• 1 * 2in1 PCB (Pos. 20)
• 2 * 100nF capacitor (Pos. 8)
• 1 * multi-pin 2 pins wide (part of pos. 24)
• 1 * multi-pin 6 pins wide (part of pos. 24)
• 1 * multi-pin 8 pins wide (part of pos. 24)
• 1 * resistor 10 kOhm (brown-black-orange-gold, pos. 7)
• 1 * resistor 1 kOhm (brown-black-red-gold, pos. 6)
• 1 * resistor 220 Ohm (red-red-black-gold, pos. 5)
• 1 * diode 1N4148 (pos. 1)
• 1 * IC socket 8 pins (pos. 10)
• 1 * IC socket 18 pins (pos. 9)
• 1 * IC 6N138 (pos. 2)
• 1 * IC MCP23008 (pos. 15)
• 2 * Connector cable pin-female/pin-female
• 1 * MIDI socket (DIN socket 5 pins)
• 1 * 2in1 PCB (pos. 20)

1.4.1.2 HowTo:

1. Start with assembling the diode onto the PCB. Be careful to do this the right way - the small black (or white) stripe on one side of the diode must fit the same side of the white stripe on the PCB!
2. After that solder the resistors.
3. Then assemble the IC sockets, but do not fit the ICs yet. We will do this at the end of this task.
4. After that, solder the capacitors and the multi-pin-rows.
5. Now insert the ICs into the socket. Be careful to put them with the notch on the IC towards the hole of the white rectangle showing on the PCB!

For the MIDI socket you have to cut off one side of the female/female cable and solder this side to the DIN-socket. Connect the cables to pin 5 (2nd from left) and pin 4 (2nd from right).

1.4.2 Step 2: Encoder boards

1.4.2.1 You need (for one Encoder PCB):

• 2 * rotary encoder with pushbutton (Pos. 17)
• 2 * 100nF capacitor (Pos. 8)
• 1 * multi-pin 6 pins wide (part of Pos. 24)
• 1 * multi-pin 2 pins wide (part of Pos. 24)
• 1 * encoder PCB (Pos. 19)

1.4.2.2 HowTo:

1. Notice! Due to the mounting of the encoders on a front panel, the 6-pin-row must be soldered from the bottom of the PCB (pin numbering will be 1..6 from the lower side of the PCB!). The picture below shows the WRONG component side! (newer images will follow)
2. The order of the following steps is not important: Solder the capacitors, the 2-pin-rows and the Encoders on the board (on the upper side) - that's it.
3. You have to do this twice - you need two encoder boards.

Alternative: Mount the pin row at the bottom of the PCB:

1.4.3 Step 3: Pin row on the Hifiberry

1.4.3.1 You need:

• 1 * HiFiBerry DAC+ RCA, Raspberry Pi Shield (Pos. 4)
• 1 * 2x25pol.-Stiftleiste, gerade, RM 2,54 (Pos. 11)

1.4.3.2 HowTo:

1. For this part you should take some time. Damaging the Hifiberry because you are in a hurry won't make your day!
2. First of all: cut the 2*25 pin-row to 2*20 pin (perhaps with a cutter).
3. Place the pin row on the Hifiberry and start soldering on the back of the Hifiberry. I always solder pins which are not close together to avoid hot spots. You take a few pauses in between to have the PCB cool down. Never let the PCB get too hot, because otherwise solder on the components' side may melt and components may fall off or become shorted.

1.4.4 Checking everything

Congratulations - you're halfway through!

Now you should double-check everything you soldered:

• Were the components soldered in their correct orientation (e.g. polarity, pin layout)?
• Are there any solder bridges between pins? Remove them!
• Is the diode on the 2in1-PCB correctly oriented?
• Are the ICs pointing in the right direction?
• Are all pins of the ICs in their sockets?

Hint:

• Use a magnifying glass and bright light to check.

1.5 Connecting the cables

1.5.1 You need:

• 1 * Raspberry Pi 2 (Pos. 3)
• 1 * HiFiBerry DAC+ RCA (Pos. 4)
• 1 * Adafruit PiTFT Touchscreen Display, 2,8 Zoll (Pos. 16)
• 1 * Raspberry Main Bus Ribbon Cable (Pos. 21)
• 3 * Mini-ribbon cable (6 pin female connector to 6 female jumper connectors(Pos. 22)
• 2 * Connector cables pin-female/pin-female (Pos. 24)

1.5.2 Raspberry Pi and Hifiberry DAC+

Put the Hifiberry DAC+ onto the Raspberry Pi. With the Hifiberry there come 4 distance pieces and 4 screws (all plastic). Put them together as shown in the following picture.

1.5.3 TFT

Time for connecting the main ribbon-cable using the (female) 40-pin-connector to the Hifiberry. At the other end of the cable there is a (female) 26-pin-connector. This one must be connected to the PiTFT. If you have a clone PiTFT which has no suitable port you have to solder one in or use a gender changer. The original PiTFT has both male and female connectors.

1.5.4 2in1

The 2in1-PCB must be connected using one of the mini ribbon cables. The 6-pin connector must be located towards the PCB. Pin 1 is on the bottom left (component side up). On the other end of the cable there are 1-pin female connectors. They must be connected to the following pins on the (male) 40-pin-conenctor in the middle of the main ribbon cable.

Wire no.	Function	GPIO no.	Pin on Raspi no.
1	Vdc 3.3V	3.3V	1
2	RxD	RxD	10
3	I2C SDA1	08	3
4	I2C SCL1	09	5
5	Vdc 5V	5V	2/4
6	GND	GND	6/9

Next connect the DIN socket (MIDI) to the 2in1-PCB. The connector on the PCB is the 2-pin one located in the upper right corner of the PCB.

Wire no.	Function	MIDI-IN pin no.
1	MIDI-IN-5	5 (MIDI connector: 2nd from left)
2	RxD	4 (MIDI connector: 2nd from right)

1.5.5 Controller

This step is a bit tricky. Depending on your setup it may be useful to solder the 6-pin header row to the back of the PCB, so you can front mount the encoders. In my setup, I bent the 6-pin-row by 90 degrees. The original Zynthian doesn't have this modification, so the pin numbering in the pictures is different!

Looking on the top of the PCB with the 6-pin-row down:

• Mounting the 6-pin-row on top of the PCB: Pin numbering starts on the left of the row!
• Mounting the 6-pin-row on the back of the PCB: Pin numbering starts on the right of the row!

Some encoders have reversed pin ordering, so you have to change A and B pins.

1.5.5.1 Controller 1

Wire no.	Function	GPIO no.	Pin on Raspi no.
1	Enc1-B	25	37
2	Enc1-A	27	36
3	Enc1-SW	23	33
4	Enc2-B	26	32
5	Enc2-A	21	29
6	GND	GND	30

Wire no.	Function	Pin on 2in1
1	GND	-
2	Enc2-SW	X07

1.5.5.2 Controller 2

Wire no.	Function	GPIO no.	Pin on Raspi no.
1	Enc1-B	04	16
2	Enc1-A	03	15
3	Enc1-SW	02	13
4	Enc2-B	00	11
5	Enc2-A	07	07
6	GND	GND	14

Wire no.	Function	Pin on 2in1
1	GND	-
2	Enc2-SW	X08

1.5.6 Alternative cabling

An alternative cabling can be done with an old floppy ribbon cable. You won't need the 3 minni-ribbon-connectors (6-pin) but have to solder 6-pin connectors on the floppy cable (40-pin-ribbon). The cabling plan is the same as above.

Solder a 6-pin connector

6-pin connector for the 2IN1 is ready

The complete cable ready for installation

Cable installed

1.6 Creating the SD

1.6.1 Getting the Image

Currently the image is only available via torrent:

Download torrent link (sha1sum: 0067db634260e45f50467c1f90c322187a182872)

1.6.2 Writing the image to the SD card

If you got the whole image you can write it to an SD-card. Depending on your OS you have to choose how to create the SD-card. You need a minimum size of 16GB, better 32GB for more sample-sets in future. There is a really good manual for this at | https://www.raspberrypi.org/documentation/installation/installing-images/.