Version 1.1 of the Isolated USB Hub PCB arrived this morning from Iteadstudio and the first thing I noticed was the silkscreen looks to be aligned correctly! It would be nice if they all came correctly aligned but for the price I shouldn’t complain too much ;-).
Most of the parts was salvaged from the old v1.0 PCB with help from the S-998P, excluding the LEDs which I swapped out for some of the red 1206 LEDs which arrived a few days ago (I find them a little easier on the eyes vs white/blue LEDs). The speed selection (FS/LS) can now be set by the solder jumpers on the bottom of the board which makes more sense than using jumpers when it’s permanently connected to the hub.
After the board was populated all seemed OK on testing. In the picture the hub is set to self powered (set via the solder jumper) but is actually being bus powered (with the mouse, 2 keyboards and USB memory stick it used less than 300mA).
Isolated USB Hub v1.1 project files (Eagle):
- If the hub is bus powered bridge the right side to the middle of solder jumper SJ3 (or to select self powered bridge the left hand to the middle).
- The USB speed must be set to the same speed (FS=Full Speed or LS=Low Speed) on both sides of the isolator using either the solder jumpers (SJ1/SJ2) or the pin header jumpers (JP3/JP6) if populated.
- If you wish to use the isolation provided by a wall wart or other power supply the two sets of 0.1″ holes “under” the isolated DC-DC converter can be linked (when doing this do not fit JP1).
- For a case I have used the dangerous prototypes Sick of Beige DP10080 with 18mm standoffs to allow for the height of the dual USB sockets.
- X1 (Vertical USB connector) should not be fitted when using the USB hub.
- Power for the Isolated USB Hub can be via supplied via 4.5-9 volts on USB1 (micro USB) / J1 (5.5mm OD/2.1mm positive tip barrel connector) / J2 (5mm pitch screw terminals) / JP1 (pin header – top row) / spade screw terminals. Alternatively it can be bus powered (5 volts only) via the upstream/data micro USB connector (USB2) by joining the top two G pins and top two V pins on JP1 with 0.1″ jumpers. Do NOT try to use multiple methods of power and ensure if power is not provided by the data USB (USB2) the jumpers on JP1 are in the lower (storage) position.
- Upstream/data USB is connected via USB2 to the computer.
Safety Warning The isolated USB hub was designed for low voltage isolation (ground loops, etc.) – use with high voltages is not advised, tested or safe.