shawn
Senior Member

Hmm. The code looks fine. Either the DHCP server is slow to respond or the network has high packet loss or something.

Are you saying it took a few minutes to get an IP address from DHCP? If so, would you mind pasting a small example that demonstrates what you’re doing? DHCP doesn’t normally take that long. (Slow DHCP server, maybe?)

On the Teensy, millis() calls are pretty cheap because they just read a 32-bit variable that’s updated by the “systick” interrupt. That subsystem is running all the time anyway.

Note: AsyncWebServer runs cooperatively and has similar behaviour and performance as polling/single-threading. Deeper: it runs whenever QNEthernet’s `Ethernet.loop()` is run, and that happens internally in a few...

I also just added a way to disable and exclude TCP, DHCP, DNS, and UDP. That's in addition to mDNS and IGMP. Each should just be a simple one-line change to _lwipopts.h_.

Thanks for pointing that out (removing IGMP causes build errors). I've fixed this and it will be available the next time I push. Now you should just be able to set `LWIP_IGMP` to `0` in _lwipopts.h_ and not have to...

Setting those defines inside your project source code won’t work. You either need to set those for the whole build or change them inside lwipopts.h (inside the library). The first approach is harder to do via the...

If over half the payload is QNEthernet, have you explored reducing the feature set included with the underlying lwIP stack? For example, removing TCP or reducing the number of possible sockets (all protocols), or even...

`EthernetFrame` is for raw Ethernet frames (probably not what you want here), `EthernetUDP` is for IP-based UDP, and `EthernetClient` is for IP-based TCP.

Did the “operator bool()” vs. “connected()” explanation help?

Neat! Thanks for explaining.

I'm curious, why are you using `new` to create `EthernetClient`s instead of, say, having a list of them already created? For example: std::array<EthernetClient, EthernetClient::maxSockets()> connList; // Or...

The behaviour of those functions is documented here: https://www.arduino.cc/reference/en/libraries/ethernet/ This disambiguation might also help (QNEthernet README):...

I went ahead and filed the issue: https://github.com/ssilverman/QNEthernet/issues/40 I also fixed the problem. Thanks for reporting it. (For future reporters: Please file an issue in the repo; I may or may not see...

Would you mind filing an issue at https://github.com/ssilverman/QNEthernet? Just cut & paste the text if you like. I like to track these things there.

I'm still here :) Here... I'll join now...

@defragster I have some time this afternoon to show you that starting point if you're around.

Are these libraries ones that can be found publicly, or something custom where you might need a rewrite if you can't find the originals?

Are you able to link to the code? Perhaps someone here could help find what’s causing the compile to fail.

QNEthernet is explicitly not designed for asynchronous use. See here: https://github.com/ssilverman/QNEthernet/issues/39#issuecomment-1550481187 And here:...

It uses the initialization.

Note that AsyncWebServer (and its AsyncTCP dependency) doesn’t really use QNEthernet; it uses the library’s included lwIP stack (it’s what QNEthernet uses under the covers). My opinion is that those “Async” libraries...

In theory, QNEthernet can run from a single thread, but it's not designed for being used from multiple threads or contexts (one example is some access from an ISR and some from somewhere else). I also find that...

Pro tip: when pasting code, use the "" tags (or the "#" button), and that will keep the spacing and formatting. It's hard to follow when all the leading spacing is missing. (Yes, cut and paste into an IDE that reformats...

Which Ethernet library are you using? Are you able to post your whole program? What error message are you seeing? Is that “no data available” message being printed on the Teensy side or on your PC? I suspect that...

Here's my general project structure: 1. Main loop() loops through a list of mini "programs" that execute their own loop(). I don't use threading because it can kill performance. For example, I have an LED refresh...

Are you looking to write one yourself or find an already-made one? If the second, contact me privately; I've made several that are used in commercial projects. If the first, can you describe the difficulties you're...

Is there any interest if I did another one of these today? (I’m in Pacific Time.)

Sorry, I meant in QNEthernet. I don’t see how that would increase complexity, unless you’re using the randomly-generated local port as some sort of ID or something? (Or something else I’m not thinking of.) I was...

You might be able to get away with a single UDP socket instead of two. You can use a single UDP socket for listening on one specific port, and that same socket for sending to arbitrary locations.

I know it's last minute, but I'm hosting one again now. We'll be talking "better Ethernet throughput," per a request. Update: I had to step away for a little bit; I'm back now.

@beermat - Thank you for the question. I'll begin by summarizing my mental model of the library: 1. It's an Arduino API-style layer on top of lwIP, with the assumption that all network functions are performed from the...

I just added a way, in QNEthernet v0.21.0, to check for the presence of a crossover connection.

I just released v0.21.0. The changes: ### Added * Added `EthernetClass::linkIsCrossover()` for checking if a crossover cable is detected. * Added entropy-based random number functions, `entropy_random()` and ...

Can you be more specific? I don't understand the question. Do you mean just how you enable VLAN things in general? Update: Did you mean "setting up VLAN"?

The function signature of `LWIP_HOOK_VLAN_SET` can be found here: https://github.com/ssilverman/QNEthernet/blob/24c1177975b0ce27604d5b5f209366f17247c8ac/src/lwip/opt.h#L3024 See also `LWIP_HOOK_VLAN_SET`...

So far, there’s been no rhyme or reason to it. Curious, what times are typically best for you?

I like this from an artistic point of view and would love to recreate it.

Making a structure’s or class’s members volatile disables the ability to use the members as non-volatile; this is not desired. The correct approach is to add volatile-labelled functions, which tells the compiler to...

I don’t agree that elapsedMillis is volatile-safe unless its internal `unsigned long ms` variable is also volatile. It’s true that `millis()` is volatile-safe, but elapsedMillis is not. Both its assignment operators...

True, but elapsedMillis’s `unsigned long ms` isn’t volatile.

I'm not seeing `volatile` in teensy4/elapsedMillis.h (or in teensy3's version). Am I missing something? I was going to suggest these other alternatives: 1. C++'s const_cast<>() can remove volatility, but knowing...

Agreed that a heads-up is better, but sometimes I don’t know I have time until I do. :) This is all ad hoc to me for now.

I'm hosting another one if anyone would like to join. I'll be on for about an hour or two.

Anyone interested if I did this again?

Those two Ethernet libraries you mention don’t work with the W5500 hardware. They work with the built-in PHY and the Ethernet Kit. Having said that, maybe you were planning on using the Ethernet Kit? I can tell you...

You can also see the failure sometimes in the unit tests. Sometimes one of the tests fails to acquire a DHCP address and sometimes the UDP test fails because it doesn't receive an SNTP response within 20 seconds. To run...

Have you considered using the Ethernet Kit to use Teensy 4.1’s built-in Ethernet PHY? The QNEthernet library, for example, lets you change a number of settings and sizes. I’ve personally successfully used dozens of...

I understand. In any case, I wrote a write-up of how to do this if anyone needs: https://github.com/ssilverman/QNEthernet/blob/d46986e6fef40e9be2e88db56d50239bb0d1b80c/README.md#configuring-macros-using-the-arduino-ide...

This thread may help: https://forum.pjrc.com/threads/66201-Teensy-4-1-How-to-start-using-FlexIO

Yeah, I decided to do two things: rely on the now-supported printf, and split stdPrint into stdoutPrint and stderrPrint, along with a new QNETHERNET_ENABLE_CUSTOM_WRITE macro.

@bicycleguy Does quitting and restarting the IDE achieve clearing the cache for you? I'm curious.

In PlatformIO, in order to get `IntervalTimer` to compile, this might be needed in your platformio.ini file: build_unflags = -std=gnu++14 PlatformIO's platform/teensy/builder/frameworks/arduino.py file sets...

I just released 0.20.0. The changes: ### Added * Added `EthernetFrameClass::size()`, for parity with `EthernetUDP`. * Added internal entropy functions to remove the _Entropy_ library dependency. * New...