This is transmit only, so it's pretty much limited to broadcasts (can't do ARP). That's good enough for e.g. sensors.
Not always. The physical layers are incredibly different, and while it is true that most 1G devices also support 10M/100M, we found the hard way that some 10G switches and NICs don't.
I’ve had 10G cards that would only negotiate down to 1G or only do 10G. But those were over Twinax. I’ve never use 10G on twisted pair.
Back in my day we were excited about 100Base-T and called it Fast Ethernet :).
Oooh! Now do 10Base2!
Is a micro-controller able to broadcast through an ethernet port something remarkable?
Obviously this upvoted enough that it's causing a buzz, but I'm not an embedded guy and don't really understand why.
Many microcontrollers, especially higher-end ones, have built-in dedicated hardware, called peripherals[1], to handle complex and/or high-speed interfaces like Ethernet.
The Pico does not have an Ethernet peripheral, so this project relies on bit-banging[2], a brute-force approach to IO. However, the Pico does have the PIO[3], which is a general-purpose IO peripheral, so it's not pure bit-banging in the traditional sense.
While it's cute, it's not super remarkable. People have done bit-banged HDMI[4] on the Pico for example. However, Ethernet access can be very useful in a Pico project.
[1]: https://electronicguidebook.com/what-are-microcontroller-per...
[2]: https://en.wikipedia.org/wiki/Bit_banging
[3]: https://hackspace.raspberrypi.com/articles/what-is-programma...