Close
0%
0%

StickHub - The Space Friendly 7-Port USB 2 Hub

Shaped like a USB stick, ideal for a Raspberry Pi or Jetson. Connect up to 28 devices to a Pi.

Public Chat
Similar projects worth following
A tiny (16.5 x 40mm) USB 2.0 hub with 7 ports for connecting lots of USB devices to, for example, a Raspberry Pi or Jetson board. Each port uses a JST SH 1.0mm pitch connector, making a hub assembly far more compact and lightweight than possible with regular USB plugs.

In contrast to cheap hubs each port supports LS, FS and HS independently for optimal performance of all devices. Power is taken from the upstream port by default, but removing the fuse (or replacing it by a diode) allows using external 5V supply.

Full ESD protection: A TVS per data line, a Vin TVS, a +5V TVS, and a 2012 capacitor near each power pin/pad. Inrush current control and short circuit protection. 308uF downstream capacitance + pads for more. Individual status LEDs for the downsteam ports.

Features & Specifications

  • One upstream port (plug) communicating at HS (480Mbit/s) or FS (12Mbit/s)7 downstream ports with 'Multiple transaction translators (MTT)' for HS, FS or LS (1Mbit/s) speed per device.
  • Full ESD protection: A TVS per data line, a TVS for Vin, a TVS for +5V, and a 2012 capacitor per power line
  • Short circuit protection: The Dialog IC will prevent short circuits from doing damage, switching faster than a polyfuse.
  • Inrush management: The Dialog IC also prevents the downstream port capacitors from overloading the host when powering up the board
  • A status LED for each downstream port
  • JST SH 1.0mm connectors for the downstream ports
  • Solder pads for using an external 5V power supply
  • Solder pads to increase downstream capacitance
  • A slot and groove for retention or housings
  • 16.5mm wide, 40mm long (31mm inserted), and 6.5mm thick
  • Very low power consumption: 0.6mA suspend - 167mA with 7 HS devices
  • Open hardware: Schematics and design files included

Hub IC datasheet: https://www.maxlinear.com/ds/xr22417.pdf

Background

More and more modules used in robotics, machinery and product prototyping have native USB capabilities. Often of the USB 2.0 FS kind, as most MCUs won't need extra hardware for signalling. Your average dev board supports up to 4 USB devices, plug in some cameras and you'll have no other option than to use a hub for those Arduino, Teensy, STM32 or similar modules. Or a GPS. Or any fancy motor controllers... You get the point.

Thus came the idea to create a hub that would be a great addition to any robotics toolbox. It would need to be very small to fit drones or small service robots. ESD protection to allow some rough handling would also be great. Being a 'known quantity' / open design as final goal.

Parts used

Above parts are currently all in stock in Mouser and LCSC.

  • ... you might learn something

    rbtsco10/21/2020 at 14:07 0 comments

    A lot of small tweaks based on this Reddit PCB review request. One fairly visible tweak is to add an optional 6.3mm 'ESC style' mounted capacitor to more than double the downstream port capacitance:

    There was also a bug in the schematic where the power switch wouldn't turn on. Option 1 was to keep the power sequencing and feed the hub IC directly from the USB plug to have the 1.8V to turn on the Dialog switch, or (option 2) tie the 'ON' pin of the Dialog switch to 'Vin' and let it protect all of the device, dropping any power sequencing. Since it's a bare PCB and the solution would be simpler I went with no. 2.

  • Dialog led to Dialog

    rbtsco10/19/2020 at 14:03 0 comments

    Several people pointed out it might be wise to do a little more power management than straight-up passing the 5V downstream. In specific this dialog. Looking for a solution that wouldn't compromise the device in terms of size and costs I came across the very affordable Dialog SLG5NT1487V load switch to switch off the hub power on any short circuit and regulate the inrush current of the newly added capacitors for the downstream ports. To keep things small all downstream ports share two ceramic capacitor banks made up of 22uF caps.

    The power switch enable is tied to the hub 1.8V supply, which is the last to turn on according to the datasheet.

    The implementation of above looks like this:

View all 2 project logs

Enjoy this project?

Share

Discussions

Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates