It's worth your while to buy another domain. You could keep the .tk running.<p>Some sites shadowban .tk, Reddit probably still does. Search engines probably downrank it. That's because it's free and has been used for a lot of spammy stuff.<p>This makes it harder for people to share and harder for people to find. That might just put a damper on your hobby, but it might also mean you won't get random emails about jobs you might want. (If you're interested in that.)<p>I only mention it because I learned that the hard way many years ago.
This is a wonderful project! I'm old enough to remember the days when Ethernet adapters for commercial computers were made of individual logic gates. The Ethernet adapter in the VAX 11/750 I used in the early 80's was two large Unibus boards full of TTL logic: <a href="http://gunkies.org/wiki/Digital_Ethernet_UNIBUS_Network_Adapter" rel="nofollow">http://gunkies.org/wiki/Digital_Ethernet_UNIBUS_Network_Adap...</a>
What a mervell of retro-computing. I think the author should definitely contact Ben Eater, as this is an excellent material for the next video.<p>Aside from this, Arduino shields for Ethernet are available for quite some time, but they often contain the more advanced chip than the atmega328p itself. Here OTOH the author builds from the ground up. Simply amazing!<p>That being said, I think most of the ppl that are serious about their arduino networking will use CAN as their network of choice (<a href="https://en.wikipedia.org/wiki/CAN_bus" rel="nofollow">https://en.wikipedia.org/wiki/CAN_bus</a>).
Oh wow.<p>I had thought this was, "I simulated it in a high level HDL and synthesized it to gates".<p>No, this is... I built it with physical chips. Brilliant build and write-up!<p>Edit: This is beautiful for a second reason... The lack of regard for doing things "correctly". The ugly clock circuit is horrifically unreliable... But just reliable enough for it to still work.<p>It reminds me of Muntzing.<p><a href="https://en.wikipedia.org/wiki/Muntzing" rel="nofollow">https://en.wikipedia.org/wiki/Muntzing</a>
So all I need are link pulses to fake the other end of an Ethernet connection to keep it alive?<p>This makes building a data diode much simpler than I thought it needed to be. Thanks!
Wow, this is fantastic! I had a couple of questions. The author states:<p>>"According to the 10BASE-T spec, each frame starts with a fixed synchronization sequence of 64 bits, first 62 of which are alternating ones and zeroes and the last two are ones."<p>I believe the intention of the "preamble" is to provide clocking and synchronization for the circuit so that it knows where to find the start frame delimiter and subsequent fields. Is that correct?<p>My other question is at what point does the circuit drop frames that are not intended for it? Does that happen in layer 1 or layer 2? I realize this happens less in modern switched Ethernet networks but it is still possible for a host to get an Ethernet frame for where the destination MAC address does not match any of those burned-in addresses on the Ethernet adapter. Does the transceiver always read the entire Ethernet frame even when the destination MAC address field it reads is incorrect? The maximum Ethernet frame size is 1518 bytes which seems like a lot of data read if the MAC address is not valid for the host.
<i>However, some hardware I have sometimes produced longer preambles</i><p>How long were they, and did they happen to coincide with short frames? It's been a <i>long</i> time since I've worked with 10M Ethernet PHY but I vaguely remember some non-standard implementations would lengthen the preamble instead of padding the "tail" of the frame.
Its been way too long since I touched a breadboard, but what software was the post using to simulate this? I would expect that the requirement for ~ns precision (microwave frequencies) would involve a lot more tedious calculations for designing the circuit.
Look on Hackaday for "Why do you need to use decoupling caps". I am not seeing any talk of decoupling caps in any of this persons writeups. Maybe they are there and I am just not seeing them. It used to be when designing with LS ttl you needed one per chip to make sure switching noise did not get onto your power supply rails.
Otherwise, a great project for learning.
This is sick. I also read their post about the making a discrete computer and didn’t expect them to be also writing a compiler from scratch. Something I’ve only been dreaming about.