Good evening everyone,
I come bearing all that I am coming through in my adventures using the Uno Q.
By now, we all know that the board can’t power stuff from the USB,
so I got myself an Adafruit CH334f USB hub hoping to be able to power it via the 5V pin.
Since I only have a pendrive and microphone, I thought this was well within the board’s capabilities.
Yesterday I tried this setup: bench PSU → Uno Q Vin → Uno Q 5V → USB HUB 5V pin.
I tried with both 12V and 24V, but the HUB would not power up.
Probing the powerline between the two boards I found a voltage of around 330mV and measuring the power from the Q without load I found a staggering 4.7V.
Just moments ago I tried another setup: bench PSU → USB HUB 5v → USB C to USB C → Uno Q USB.
Now the HUB has enough power, but the Q keeps boot looping and
I can’t raise the voltage, with this setup, without smoking the HUB in the process.
Now comes my question: how am I supposed to power up my system?
I hope my board has a defected 5V module, and this is what forces me to now use a dual power supply for both the Q and the HUB.
This board was supposed to replace a PI 5 (which is too bulky and power-draining) in a robotics project of mine, but with all the additional components and limits the task is requiring it’s not even fun anymore.
Am I the one asking too much of the platform or is someone else in my same situation?
Your first setup assumes that UNO Q's 5V pin is the output from the on-board buck converter, but it's not. The 5V pin on JANALOG and JMISC are 5V_USB_VBUS, which is the 5V directly from the USB-C connector. If powering the board via VIN, with no power supply via USB-C, then the 5V pins are useless.
See the "Same power net as the USB bus" for the 5V pin in the pic below.
UNO Q can be powered from 5V through USB-C, 5V through 5V pin, or VIN Pin. the 5V USB Net and 5V from the buck are OR'd to power the board, but the 5V buck is never sent to the 5V USB net.
Your second setup is closer, but from the datasheet for the CH334, I believe only 500mA are available on the hub's outputs. This is likely not enough for the UNO Q, and it fails to boot up.
Ok, it took me more than I wanted to respond with both work and the flu returning for the third time, but here I am.
So, I managed to make it work, but not from the VIN pin.
As I remembered, the board needs at least 7 volts from VIN to power up.
I decided, instead, to backfeed 5 volts into the system via the 5V pin.
Not the more orthodox way, but it hasn’t failed me in the past.
The system works fine with this setup, but I had some enumeration problems on the hub.
To cut a long story short, Adafruit has inverted D- and D+ on their board, making everything more complicated to hand-solder, but with some jumpers, everything works fine
