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doc: minor, fix README

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King Kévin 2022-12-21 02:12:57 +01:00
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README.md
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@ -7,7 +7,7 @@ most USB hubs are super cheap and crappy, leading to poor connection and data tr
there are industrial USB hubs, but they are bulky and very expensive.
to solve this issue I decided to design my own USB hub, tailored to my needs.
when developing and testing hardware, you often end with a lot of USB devices connected.
when developing and testing hardware, you often end with a lot of USB devices connected (serial debugger, programmer, logic analyzer, ...).
USB allows to have up to 128 devices, but only with a maximum depth of 7.
thus you are only allowed to have a maximum of 5 USB hubs between computer and devices, and I often have to plan my setup to not reach this limit.
most 7-port USB hubs use two 4-port USB hub, the seconds being connected to the first.
@ -15,7 +15,7 @@ there are some exceptions to that, but they are rare, old, and often not adverti
this heavily limits the actual number of end devices.
the CuVoodoo USB hub is a 7-port flat USB hub, preventing reaching this limit too fast.
the incoming and outgoing USB ports are individually ESD protected.
the upstream and downstream USB ports are individually ESD protected.
this safety becomes important when developing, testing, and handling bare electronic devices.
this also comes in handy when connecting circuit with different ground potentials.
ESD protections already saved my day twice this way.
@ -27,7 +27,7 @@ it if does, there is very probably an issue with the device.
this protection allows to isolate the faulty device and not have it affect all other connected devices, or the hub itself.
see `current limitation` below for more details.
each output port is power controlled.
each downstream port is power controlled.
this allows to remotely switch on and off individual devices.
this is an important requirement when developing and testing devices, which require a power cycle.
additionally, a switch next to the USB port can force the power off state.
@ -37,7 +37,7 @@ this allows to use higher voltage power supplies to provide enough current to al
the 5V are not feed back to the host.
each USB port comes with a high voltage output power port, connected to the high voltage input port.
this allows to power devices which require more than 5V (e.g. 12V externally powered devices).
this allows to power devices which require more than 5V, with a maximum or 5A, such as 12V externally powered devices.
these power outputs are controllable along the USB port.
as with the 5V USB power output, this allows to remotely switch on an off individual devices.