PJRC Ethernet Library + wiz850io

[dimitre]

Hello, I'm working on a project and everything is running smoothly.
I've made an array of EthernetUDP and noticed the project always freeze when a certain number of EthernetUDP objects are created.

I'm using Teensy 3.2 and wiz850io, but I feel it can be reproduced in other systems.

here is the minimal code to reproduce. in my setup if you use up to 4 objects the sistem runs, if you use 5 it freeze

#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>

#define NUMBEROFPACKETS 5

byte mac[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x00 };
IPAddress ip(192, 168, 1, 201);
EthernetUDP Udps[NUMBEROFPACKETS];

void setup() {
  Ethernet.begin(mac, ip);
  Serial.begin(9600);
  for (int a = 0; a < NUMBEROFPACKETS; a++) {
    Udps[a].begin(4001 + a);
  }
}

void loop() {
  delay(500);
  Serial.println("alive");
  for (int a = 0; a < NUMBEROFPACKETS; a++) {
    if (Udps[a].parsePacket()) { //int n =
      byte packetBuffer[100]; //buffer to hold incoming & outgoing packets
      Udps[a].read(packetBuffer, 100);
    }
  }
}

 

[manitou]

Ethernet.h in the Ethernet lib is configured for a max of 4 sockets. With some work, you can change that to 8, though it affects buffer sizes on the wiznet chip. I think 8 may be the max as defined by the wiznet API.

Here is repository with a modified Ethernet lib (to use just 1 socket)
https://github.com/alex-Arc/Ethernet/tree/1-socket
discussed at https://forum.pjrc.com/threads/28975-wiz820io-max-speed?p=109591&viewfull=1#post109591

 

[dimitre]

Thanks for the prompt answer @manitou. I'll definetly take a look in this option.

 

[PaulStoffregen]

Yup, only 4 sockets are supported.

Improving the ability to more easily configure 8 sockets, or fewer than 4 with larger buffers, is on my (very long) todo list.

Long-term, the default is probably going to remain 4 sockets with 4k buffers. Larger buffers help when you have network latency.

The hardware limit is 8 sockets.

 

[dimitre]

Thanks! in fact in my application I dont' mind losing packets, I'll use a tiny TTL setting because I'm pushing pixels to LEDs.
I'll soon try this version of Ethernet library just to see if it works for my application.
https://github.com/sstaub/Ethernet3

Nice thing is actually I'm reading the Udp buffer directly inside the FastLED LEDS buffer, so I'm not even using memcpy anymore.
Each UDP port writes to a specific part of the buffer (one port for each 1464 bytes, or 488 leds) so this is why I'm looking for more ports.
I can loop through all UDP ports before updating leds.

This way I can handle 3904 pixels at a time.
My actual tests are running very fast, handling great 180 fps using 3 UDP ports.

If it doesn't work I'll try to use the first byte as a packet index, making teensy knowing in which position of the LED buffer it should write the UDP packet.

Ideas are welcome. Videos soon.