diff --git a/README.md b/README.md index cb006c7..d7c79ed 100644 --- a/README.md +++ b/README.md @@ -1,8 +1,50 @@ # Ethy A project to learn how ethernet and the TCP/IP Stack works. -## Components (Possible) +## Design -- RP2040 -- ENC424J600 -- Lots of WS28?? LEDS +Ethy is designed to learn how ethernet and the entire OSI stack functions and +how it can be used on low-memory devices. + +This project started in November, so the project is made in a christmassy +theme by making an LED display driver for a christmas tree over ethernet. + +![block diagram of Ethy](../docs/main_block_diagram.svg "Main Block Diagram") + +The block diagram above shows the main components of the system. First of +all we have the Ethernet chain, which is just a RJ45 connector together with +the magnetics and a chip to convert data from the microcontroller to the +differential signals. Another project that attempts something similar uses +the W5100 but is still a bit of an overkill for what I want to use. The +less of the process the chip automates the better. + +The second chain is the USB and power. Although the main way to connect +to the device will be via ethernet, I still wanted some other way to talk to +it. Given that the RP2040 has an onboard USB PHY, this seemed the easiest +way. At the same time the USB PD standard (PD 2.0 and PD 3.0 have +a selection of easily attainable chips) allows for 100W of power. +How much of that will or can be used is still being figured out, but it makes +for an easy way to power multiple LEDS. + +Lastly, from the USB PD and the RP2040 together power the LED strips. The +device should both support WS2812B and WS2815B LED strips. Since the user +may plug in either a WS2812B or WS2815B LED strip, the voltage needed for the +should be automatically detected. The easiest way of doing that would be to +use a voltage divider in the same way that the base power profile of the PD +standard uses it. + +### USB Power Delivery + +#### Possible PD chips + + - STUSB4500 + - STUSB4500L + - Some Texas Instruments chips + +#### Possible DC/DC chips for controllers + + - TPS56320x (except it only goes to 17V) + +### Ehternet PHY + +### LED Strip diff --git a/docs/main_block_diagram.svg b/docs/main_block_diagram.svg new file mode 100644 index 0000000..b06f3e4 --- /dev/null +++ b/docs/main_block_diagram.svg @@ -0,0 +1,357 @@ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + RJ45 + + Magnetics + + PHY + + RP2040 + + USB + + USB PD + + 3V3 + + WS2812 + WS2815 + + + + + + + + + + +