ESP32 Forum

Workings of existing T1 PHYs are POOORLY documented, but since a lot of automotive vendors have to submit to Linux upstream whether they want it or not, there is plenty of code for reverse engineering. For example I found a quite good register description of tja1101 in a linux patch here https://patchwork.ozlabs.org/patch/926660/

And as for T1S samples, you are basically stuck if you are not an IEEE 802.3 member, and you have to rely on docs passed around on USB sticks

I think the number 1 problem with all those busses is that that you are almost always have to reinvent the bicycle whenever you just want a few MCUs to communicate with each other as no existing solution the most typical use cases.

• i2c multimaster hacks - well, they are hacks, and you are bound by i2c's low speed.
• rs485 based buses - no hardware MAC or packet processing, you have to do everything in software and this limits your speed.
• CAN - has the holy grail of features, but speed is a limiting factor, complex bus failure modes hamper field extendibility.
• Regular or daisy chain ethernet - need hub chips, wiring, crystals needed, STP nightmare in case of daisy chaining.
• External AMBA - near no adoption.
• i3c - range, poor adoption, multimaster is nice, but requires all master nodes to be programmed for it.

You are almost always have to hack an existing solution, or build your own serial protocol with MAC and packet handling on discreet logic or FPGAs. This is why 10base-t1s is so important.

just a small addition:
Realtek is also busy working on xBASE-T1 chips like the RTL8201G-VB ; see
https://blog.csdn.net/xch520xx/article/details/88385070
https://dutch.alibaba.com/product-detai ... 96170.html

I expect a better price from them...

indeed 10BASE-T1S seems to be the next-generation industrial bus that we need!

For those that want to add an 10BASE-T1S to their design, there seems to be a new chip VS731 chip:
10BASE-T1S Ethernet and CAN-FD Transceiver with a 20MHz SPI Interface in a QFP48 package.

For product brief, see http://www.vsitech.co.kr/tech/tech1