Teensy 4.0 - Ethernet I'm guessing its not avaliable

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mhoneywill

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Hi,
Excited by the new Teensy4.0

It looks from the photo's that the chip that's used is the iMXRT1062 but on the NXP website this chip is not listed

https://www.nxp.com/products/proces...microcontrollers/i.mx-rt-series:IMX-RT-SERIES

It looks like this chip supports an Ethernet interface but looking at the pinout of the Teensy4.0 it looks like these pins are not exposed. Is this correct? I'm guessing we are unable to use this functionality of the chip which is a shame. Any thoughts anyone?

Are circuit diagrams for the Teensy 4.0 available?

Ideally we would want to have twin Ethernet ports connected to the device

Regards

Martin
 
NXP has an evaluation 1060/1062 board which includes Ethernet (RJ45). The NXP SDK has Ethernet examples based on lwIP and RTOS.

It is unlikely T4 will support Ethernet because supporting packet arrival interrupts, network buffer and timer management almost necessitates an RTOS. It seems the Teensy programming model is more tuned to having a SPI-based network coprocessor (WiFi/ESP32 or hardwired/wiznet), where the housekeeping of TCP/UDP/ICMP/IP can be handled by the coprocessor. Paul made a limited number of Ethernet breakouts for the T3.5/T3.6 evaluation. The early evaluation used lwIP with polling, see T3.6 ethernet testing, but there was no further development.
 
Is there anyone contemplating creating a breakout board with WiFi? ESP32 or their newer chip.. whatever.. I have a project that could use the FPU power of the T4 but I have to have WiFi access to it. I think I could design a board to do it (but no guarantee since its been 25 years since engineering school), but my soldering skills are sub-par that I doubt I'd succeed in actually building it considering just how small the T4 is (I was shocked when it arrived.. much more teensy than my T3.5).
 
BLE is not ideal (I need to run a webserver) and was hoping to use the ESP32/whatever to do that and then just interface to the T4 through serial, etc.
 
That's a bummer ! There are two ETH interfaces integrated and none of them are accessible ! That's silly!
And no, you don't need a RTOS to manage Ethernet.
Nobody had the idea that one Teensy could be used to process some Ethernet signals (aka EIP or else)? Because it's fast it would have been an ideal candidate.
Now you need to buy the fill Dev Kit for $100 from NXP to just have RJ45 connected to the CPU!
Smart guy ! ;-)
 
PJRC went with the smaller 1.4" Teensy size T_4.0 version to get a working board with the NXP 1062 processor.

Like the T_3.6 that bought out needed on chip pins for Ethernet - indications on this thread are that a updated larger T_4.x board will have not only the pins brought out but onboard control chip : Read this thread :: Pins-to-bring-out-on-a-hypothetical-larger-Teensy4

Indeed Paul is one smart guy - but just one guy. And this time in 2019 the IMXRT 1062 was barely publicly available with limited or no guarantee of delivery when he committed to move up from the 1052 - it went through 9 months of Beta until production shipped. Paul's noted goal somewhere was getting an Ethernet equipped version.

If you really want Ethernet - you can get it on USB Host … part of the development for T_4 … or wait until the next Teensy indicated in the above thread is released.

This post 19 October 2019 shows concept on the drawing board:: Pins-to-bring-out-on-a-hypothetical-larger-Teensy4?p=219280&viewfull=1#post219280
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That's a bummer ! There are two ETH interfaces integrated and none of them are accessible ! That's silly!
And no, you don't need a RTOS to manage Ethernet.
Nobody had the idea that one Teensy could be used to process some Ethernet signals (aka EIP or else)? Because it's fast it would have been an ideal candidate.
Now you need to buy the fill Dev Kit for $100 from NXP to just have RJ45 connected to the CPU!
Smart guy ! ;-)

As defragster noted in post #7, there might be native Ethernet with follow-on Teensy 4 (requires 12 pins from the 1062). If you compare the NXP ethernet chapters in the Teensy 3.6 and Teensy 4 reference manuals, you will see the architectures are quite similar. It is likely the lwIP lib (no RTOS) used in testing the limited-production T3.5/T3.6 Ethernet adapter will work on the native Teensy 4 Ethernet (see post # 2 above) The T3.5/T3.6 ethernet testing has some TCP and UDP performance numbers using lwIP (polling and callbacks).

FYI, here are some TCP/UDP performance numbers for a USB Ethernet dongle on T3.6 and T4. The USB ether uses the FNET TCP/IP lib with Teensy threads.

As you noted the NXP SDK supports native ethernet on the NXP 1052 and 1062 eval boards using lwIP and optionally FreeRTOS. Here are some TCP/UDP numbers for NXP eval boards, pre-Teensy4 testing.

And of course there is the widely supported SPI-based Wiznet coprocessor module (WIZ850io/W5500).
 
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Nobody had the idea that one Teensy could be used to process some Ethernet signals (aka EIP or else)?

That's absurd. Of course Ethernet was considered. Same with the 24 bit LCD interface and camera interface and SDRAM bus and the 2nd FlexSPI port, none which aren't supported by Teensy 4.0.

Conscious & well informed design trade-offs were made. Ethernet was intentionally not supported. This was not an oversight. It was an informed and carefully considered decision, to make *many* other extremely important features available on Teensy 4.0, by sacrificing Ethernet.

Because this was an informed and intentional design choice, with planning for future Teensy, the GPIO pins needed for Ethernet were kept reserved (not assigned to accessible pins on Teensy 4.0), so they would be available for an Ethernet PHY chip on future Teensy models. Indeed a future Teensy model in the Teensy 3.6 form factor will have an Ethernet PHY chip, as mentioned on that thread about future pinouts.

You might argue that PJRC should have made a larger board with Ethernet first, and then made the smaller board. But the business reality is Teensy 3.2 vastly outsells Teensy 3.5 and 3.6. So the decision to focus first on the 1.4 by 0.7 inch "28 pin" form factor, at a retail price similar to Teensy 3.2, was also a very well informed business decision based on many years of sales history.

Ethernet was indeed considered. Teensy 4's pin assignments were carefully planned to allow for Ethernet on the next Teensy. Technical trade-offs and business decisions were made based on years of experience in this market. None of this was an oversight or mistake or "Nobody had the idea". It was been carefully planned from the beginning*, with a long-term plan to make a larger Teensy model with Ethernet (and FlexSPI2, but not 24 bit LCD & CSI and SDRAM).


* - One minor exception was CAN3, which we didn't know in the very beginning before NXP made the 1062 chip, and we didn't know would be the only one to support CAN FD protocol. A minor change was made fairly late in the beta test (mid-2019) to drop the 8th serial port, to gain access the CAN FD.
 
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