51 lines
1.9 KiB
Markdown
51 lines
1.9 KiB
Markdown
# Ethy
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A project to learn how ethernet and the TCP/IP Stack works.
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## Design
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Ethy is designed to learn how ethernet and the entire OSI stack functions and
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how it can be used on low-memory devices.
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This project started in November, so the project is made in a christmassy
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theme by making an LED display driver for a christmas tree over ethernet.
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The block diagram above shows the main components of the system. First of
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all we have the Ethernet chain, which is just a RJ45 connector together with
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the magnetics and a chip to convert data from the microcontroller to the
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differential signals. Another project that attempts something similar uses
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the W5100 but is still a bit of an overkill for what I want to use. The
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less of the process the chip automates the better.
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The second chain is the USB and power. Although the main way to connect
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to the device will be via ethernet, I still wanted some other way to talk to
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it. Given that the RP2040 has an onboard USB PHY, this seemed the easiest
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way. At the same time the USB PD standard (PD 2.0 and PD 3.0 have
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a selection of easily attainable chips) allows for 100W of power.
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How much of that will or can be used is still being figured out, but it makes
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for an easy way to power multiple LEDS.
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Lastly, from the USB PD and the RP2040 together power the LED strips. The
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device should both support WS2812B and WS2815B LED strips. Since the user
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may plug in either a WS2812B or WS2815B LED strip, the voltage needed for the
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should be automatically detected. The easiest way of doing that would be to
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use a voltage divider in the same way that the base power profile of the PD
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standard uses it.
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### USB Power Delivery
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#### Possible PD chips
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- STUSB4500
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- STUSB4500L
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- Some Texas Instruments chips
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#### Possible DC/DC chips for controllers
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- TPS56320x (except it only goes to 17V)
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### Ehternet PHY
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### LED Strip
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