From 37636fa6cd867b1384204ad9c35b7630b2428c26 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?King=20K=C3=A9vin?= Date: Thu, 16 Jun 2022 17:51:05 +0200 Subject: [PATCH] doc: document usage --- README.md | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/README.md b/README.md index 9450845..c5e46bb 100644 --- a/README.md +++ b/README.md @@ -49,7 +49,7 @@ the board uses proper impedance and differential signal routing to provide clean design choice ============= -USB 3.0 +USB 2.0 ------- this hub is only for USB 2.0 devices. @@ -99,3 +99,29 @@ instead the following color scheme is used: usage ===== +it mainly works like a regular USB hub, at least when it comes to the data transfer. +just plug the device in a port. + +power on the Downstream Facing Ports (DFPs) is only available when the Upstream Facing Port (UFP) is connected. + +the hub can operate as bus powered (power coming from the UFP), but it would not be able to provide more than 500 mA across all DFPs. +it is preferable to connect an external 5V power supply to be able to provide 500 mA on all DFPs. +this will also turn the hub into self powered, not using any power from the UFP. +alternatively, you can connect a 6 to 40V power supply on the other power input. +the power for the hub and the 5V for the DFP will be derivate from this higher voltage supply. +the same higher voltage will be available on the power output next to the individual DFPs. + +a switch next to each DFP allows to turn off the power output on the USB and power ports. +the green LED is on when power output is available. + +the power output on the USB and power ports can also be turned on/off remotely using standard USB commands. +this power output control is implemented in [uhubctl](https://github.com/mvp/uhubctl): + +~~~ +# list controllable USB hub ports +sudo uhubctl +# switch of port +uhubctl --action off --location 1-1.4 --ports 5 +~~~ + +when too much current is drawn on the USB port, the error is reported to the host and the power output is automatically disabled.