- Tue Sep 01, 2020 6:36 am
#88631
And some USB leads have a high resistance leading to excessive voltage drop.
- Wed Sep 02, 2020 1:02 pm
#88648
A normal USB hub may output down to 4.2 V, that may be too low for your voltage regulator. Also without any handshaking, a device may only draw 50 mA from an USB port, that's definitely too low to get an ESP8266 running.
So: 1) use an USB hub that is self powered (has it's own power module). And 2) use a USB device (like cp1202 etc.) that can negociate the full 500 mA from the HUB.
At this very moment I have an ESP2866 in front of me running off an USB port, so yes, it can be done
. What may make the difference is that I added an external voltage regulator (5V -> 3.3V) instead of using the one in the FT232 (in this case), which might a bit too small for this purpose.
So: 1) use an USB hub that is self powered (has it's own power module). And 2) use a USB device (like cp1202 etc.) that can negociate the full 500 mA from the HUB.
At this very moment I have an ESP2866 in front of me running off an USB port, so yes, it can be done
. What may make the difference is that I added an external voltage regulator (5V -> 3.3V) instead of using the one in the FT232 (in this case), which might a bit too small for this purpose.
