4-Port USB Hub for Raspberry Pi Zero Manual Datasheet by Adafruit Industries LLC
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Copyright © 2017 UUGear s.r.o.   All rights reserved. 
Zero4U 
4-Port USB Hub for Raspberry Pi Zero 
User Manual (revision 1.20) 
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Copyright © 2017 UUGear s.r.o.   All rights reserved. 
Table of Content 
Product Overview ................................................................................................. 1!
Package Content .................................................................................................. 3!
Specifications ....................................................................................................... 4!
About Powering Mode .......................................................................................... 5!
Self-Power Mode .......................................................................................... 5!
Bus-Power Mode .......................................................................................... 5!
Usage Guide ........................................................................................................ 6!
Troubleshooting: USB Hub Not Recognized ........................................................ 9!
Revision History ................................................................................................. 11!
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1 
Product Overview 
Zero4U is a 4-Port USB hub designed for Raspberry Pi Zero. It extends the only data 
micro USB  port on Raspberry Pi  Zero and gives you 4  standard USB ports, which 
allows you to connect more USB devices to your Raspberry Pi Zero. 
The board size of this USB hub is exactly the same with Raspberry Pi Zero, and can 
be firmly attached under Raspberry Pi Zero back-to-back. There are 4 pogo pins on 
the USB hub board and they will attach the +5V, GND, USB D+ and USB D- testing 
pad at the back of Raspberry Pi Zero, so you don’t either need soldering wires, or the 
USB-OTG cable and USB – mini USB cable to connect the USB hub and Raspberry 
Pi Zero. 
Although it is designed for Raspberry Pi Zero, you can still use it as a normal USB hub 
for other models of Raspberry Pi, or any computer that has USB port. 
There are two versions of Zero4U, one is for Raspberry Pi Zero V1.2 (without camera 
connector) and the other is for Raspberry Pi Zero V1.3 (with camera connector). They 
have the same functionality but the location of pogo pins are slightly different. 
Also  there  are  two  revisions  for  V1.3.  The  second  revision  uses  more  surface 
mounted components (the crystal and the XH2.54 connector). 
The figures below show how they look like: 
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Reversion 1 (for V1.2 and V1.3) 
Reversion 2 (for V1.3 only) 
1~4) Downstream USB ports 
5~8) White LEDs as activity indicators 
9) Two pogo pins at back for data connection 
10) Alternative DC 5V power in 
11) Two pogo pins at back for power connection 
12) Blue LED as power indicator 
13) Upstream mini USB port 
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Package Content 
Each package of this USB hub contains: 
l  4-port USB hub board x 1 
l Plastic spacer x 4 
l M2.5 x 10mm screws x 4 
l M2.5 nuts x 4 
l Ferrite Ring x 1 (for V1.3 only) 
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Specifications 
Dimension:   
65mm x 30mm x 9mm 
Weight 
14g (net weight without any accessory) 
Standards 
USB Specification Revision 2.0 and 1.1 compatibility 
Single Transaction Translator (STT) 
Data Speed 
USB v1.1: 12 Mbps 
USB v2.0: 480 Mbps 
USB Ports 
Upstream: 1 (mini-USB or via pogo pins) 
Downstream: 4 
LED Indicators 
Power: 1 (blue) 
Port Activity: 4 (white) 
Power Mode 
On Raspberry Pi Zero: Self-Power 
On Other Models: Bus-Power or Self-Power 
Output Voltage 
DC 5V 
Output Current 
Bus-Power: maximum 500mA for all ports 
Self-Power: maximum 2A for all ports 
Static Current 
~1mA 
Operating Temperature 
0℃~70℃ 
Storage Temperature 
-20℃~80℃ 
Humidity 
0~80%RH, no condensing 
Remarks: when using Zero4U with Raspberry Pi Zero, Ethernet gadget should 
be disabled, or the USB hub could not be recognized.   
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5 
About Powering Mode 
A USB hub  could be powered by the USB  bus (bus-power mode), or be powered by 
the power supply (self-power mode). Bus-power mode is simpler as it does not need 
to have external power supply, but it has quite limited ability to power the devices on 
the  USB  hub.  When  you  are  trying to power more devices with higher current, it is 
recommended to use the self-power mode. 
This USB hub supports both bus-power mode and self-power mode. 
Self-Power Mode 
This USB hub in self-power mode can output up to 2,000mA current for all USB ports. 
When you attach this USB hub to Raspberry Pi Zero, it will take power from the Zero 
and work in self-power mode. 
If  you  use  a  USB  -  mini USB  cable  to  connect  this  USB  hub  to  other  models  of 
Raspberry  Pi,  and  you  connect  power  supply  to  the  USB  hub (via  the  white  JST 
XH2.54  2-pin  connector  on  board),  then  it  is  still  working  in  self-power  mode.  For 
Raspberry Pi A, B or A+, it will also back-power the Raspberry Pi, unless you remove 
the resistor R8 on board. 
Bus-Power Mode 
This USB hub in bus-power mode can output up to 500mA current for all USB ports. If 
you are using the first revision of Raspberry Pi A/B, the maximum output current for all 
USB ports is only about 100mA, because the USB port on Raspberry Pi (first revision) 
has a 140mA polyfuse. 
If  you  use  a  USB  -  mini USB  cable  to  connect  this  USB  hub  to  other  models  of 
Raspberry Pi, and you don’t connect power supply to the USB hub, then it is will work 
in bus-power mode, and it will draw power from the USB bus. 
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Usage Guide 
To  at t a ch   this  U S B   hub  t o   R as p b erry  Pi  Z e r o ,  si m ply   put  t h e m   back-to-back together 
and place the plastic standoff between them, then use the plastic screws and nuts to 
firmly fix the 4 corners. 
Please make sure to attach in the correct direction, so the 4 pogo pins on the USB 
hub can accurately contact to the PP1, PP6, PP22 and PP23 testing pads on the back 
of Raspberry Pi Zero. 
Now you can connect power supply to Raspberry Pi Zero, either micro USB port will 
do, then you will see both Raspberry Pi Zero and the USB hub are powered. If you 
plug a USB device into any of the 4 USB ports, the port activity LED (white) will light 
up. 
If you want to use Zero4U on Raspberry Pi Zero W, only the Zero4U for V1.3 has the 
possibility, as the positions for PP1, PP6, PP22 and PP23 testing pads are the same 
for Raspberry Pi Zero V1.3 and Raspberry Pi W. You will also need to use the ferrite 
ring (included in the package) to protect the pogo pins from WiFi interference. More 
details about the interference from on-board antenna could be found here.   
 
 
7 
The picture below shows how to mount Zero4U on Raspberry Pi Zero W, with the 
ferrite ring between them. 
Remarks: this USB hub has only one transaction translator (TT) for all downstream 
USB ports. Please try not to connect any USB 1.1 device to the USB hub; otherwise 
all devices on the hub will be slowed down to the USB 1.1 speed (12 Mbps). If you 
only connect USB 2.0 devices to this USB hub, all of devices on the hub can work with 
USB 2.0 high speed (480 Mbps), if they support USB 2.0 standard. 
If you want to connect this USB hub to other Raspberry Pi models, you will need a 
USB - mini USB cable (not included in the package). 
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In the  picture,  the  power  supply is  connected to Raspberry  Pi, and  the USB hub  is 
powered by the USB bus. This will limit the output current to 500mA for all USB ports 
on the hub. 
If  you  also  connect  an  alternative  power  supply  to  the  USB  hub  (via  the  white 
connector on board), the USB hub will work in self-power mode and it can output up to 
2A current for USB ports. 
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. lsusb
Bus 881 Device 882: ID la48:8181 Terminus Technology Inc. AePort HUB
 
Bus 661 Device 661: ID ldbb:0002 Linux Foundation 2.9 root nub
tutoflalis here
 
9 
Troubleshooting: USB Hub Not Recognized 
After you connect Zero4U to Raspberry Pi Zero, the blue LED should light up when 
you power  your  Raspberry  Pi  Zero.  If  you  connect USB  device to  the  USB port on 
Zero4U, the white LED should light up accordingly. If you type “lsusb” command in the 
console, you should see the 4-port USB hub get listed: 
What to do if your Zero4U (USB hub) is not recognized? 
If you are mounting Zero4U on Raspberry Pi Zero, please make sure the 4 pogo pins 
are all well contacted to testing pads on the Raspberry Pi Zero. Use tweezers to 
gently adjust the pogo pins if necessary. 
Have  you  ever  enabled  the  “Ethernet  Gadget”  on  your  Raspberry  Pi  Zero? 
(tutorial  is  here)  The  USB  port on  Raspberry  Pi  could  work  in  either  host  mode  or 
slave mode. By default, the USB port is in host mode, which allows you to connect 
Zero4U (a USB hub) to it; If you enable the Ethernet Gadget, the USB port is in slave 
mode, and the connected Zero4U will not be recognized. 
If it is the case, there are two solutions: 
1. Disable Ethernet Gadget via Software 
You can disable Ethernet Gadget by commenting out the “dtoverlay=dwc2” 
in the /boot/config.txt file, and then reboot. As for the cmdline.txt file, you can 
keep it as it is. 
2. Disable Ethernet Gadget via Hardware 
You can also disable Ethernet Gadget  by connecting an OTG adapter to the 
“USB”  micro USB  port on Raspberry  Pi  Zero (not  the  power  port).  An  OTG 
adapter is something like this: 
 OR   
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Pin Signal
1 Z 3 4 5
2 o.
. 0
Micro USB 3 u;
Female Port 4
5 GND
 
 
 
 
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Why connecting OTG adapter will help? It is because the  OTG  adapter has 
the  “ID”  signal  pin  connected  to  the  GND  pin  internally,  which  explicitly 
disables the Ethernet Gadget and lets the USB port on Raspberry Pi Zero to 
stay in host mode, that way Zero4U could be recognized successfully. 
Please  notice  that,  shorting  ID  pin  to  ground  can  override  the  software 
configuration. Even if you keep the “dtoverlay=dwc2” in the /boot/config.txt file, 
you can still disable the Ethernet Gadget by plugging an OTG adapter to the 
“USB”  port  on  Raspberry  Pi  Zero. This  is  convenience  if  you  just  want  to 
disable the Ethernet Gadget temporarily.   
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Revision History 
Revision 
Date 
Description 
1.00 
2016.04.04 
Initial revision 
1.10 
2017.01.23 
Update pictures for second revision of Zero4U v1.3 
Add troubleshooting of “hub not recognized” issue. 
1.20 
2017.03.21 
Add description for the newly added ferrite ring.