ESP32-POE2 No link when POE is used

[POEt_2038]

Hello,
 
I am using an ESP32-POE2 (Rev.B) board that uses ethernet with POE. When trying to get the link, it seems that when the board has been off for a long time (5/10 seconds), it cannot get the link. When I press the reset button, the board gets the link.

Trying to debug the board with the POE connected, I shorted the transistor that selects between 5V POE and 5V USB, as without it the USB to UART transceiver does not turn on.The strange thing is, after doing this, the POE link problem seems to be solved.

With all this information, is it possible that the ESP_32 is set to BOOT because this transceiver is not turned on? And that is why I don't get link on the ethernet?

[LubOlimex]

> When trying to get the link, it seems that when the board has been off for a long time (5/10 seconds)

I can't understand this part. You probably use this board in a way we've never used it here. What does this mean? How the board "has been off for a long time"? Why is it off? How did you turn it off?

[POEt_2038]

Is off becouse I did not connect the power supply, not becouse any problem. Long time means that I tried to discharge the capacitors, i dont know if this could help to reset it.

I am using a board without any modification, I just upload an example code that works in all the boards that I tried (OLIMEX POE-ISO. OLIMEX POE, my own boards that uses ESP32 chips )the code just use ethernet to test it.

The USB to UART transceiver uses the ESP_EN and GPIO_0 pins, so if the transceiver is not power on, maybe this could cause some problems initializing the micro?

[LubOlimex]

"Is off becouse I did not connect the power supply"

I have to understand the hardware setup so I can test it here myself. Without details it is impossible to see if it is a design problem or something else.

So there is nothing connected to the board and then you attach the Ethernet cable to the board with PoE enabled and it doesn't work until you press the preset button? Is this how it is or?

If you remove the Ethernet cable and then attach it to the board and the Ethernet doesn't start then the issue is within the network equipment or the cable.

I have a feeling you are resetting just the ESP32 module and this causes the LAN chip hang, because there is no clock, as written on page 34 of the document for LAN8710:

"A Hardware reset is asserted by driving the nRST input pin low. When driven, nRST should be held low for the minimum time detailed in Section 5.5.3, "Power-On nRST & Configuration Strap Timing," on page 59 to ensure a proper transceiver reset. During a Hardware reset, an external clock must be supplied to the XTAL1/CLKIN signal.
Note: A hardware reset (nRST assertion) is required following power-up..."

[A2B]

Hello, let's try to forget the previous messages and start from zero, because we are not understanding each other. The situation is as follows:
1- I take a ESP32-POE2 new from the box
2- I turn it on only with USB Cable
3- Progam it with example code LAN8720-POE2 and follow the instructions from your web
4- Disconnect the USB Cable
5- I power the board with PoE injector
6- I don't have a link to my computer
7- Reset the board with reset button and now I have a link with my computer

That is the situation, no other external connections on the board

[LubOlimex]

Hello,

I tested the same steps today with ESP32-POE2 and it doesn't behave like that here. As soon as I attach the Ethernet cable with the PoE, the network code starts working. My test can be seen in this video:

https://www.youtube.com/watch?v=_EJkPO4IA94

I have downloaded Ethernet code via the USB and checked the IP address from the serial console, then started a ping -t on the that port. Then disconnected the USB cable and instead of of regular Ethernet cable, connected PoE Ethernet cable to the board. The board came back online. I unplugged and plugged a few times to ensure it always comes online.

The code I used is this exactly:

Code Select Expand

/*

This sketch shows the Ethernet event usage with ESP32-POE2. Compile and download the code and open serial monitor to check if the boards connects to google.com.

Remember to select proper board in the board selector.
ESP32-POE2 has WROVER module with PSRAM. You should have PSRAM enabled! From Tools -> PSRAM -> Enabled.
Make sure proper COM port is selected.

*/

// Important to be defined BEFORE including ETH.h for
// ETH.begin() to work.
// Example RMII LAN8720 (Olimex, etc.)
#ifndef ETH_PHY_TYPE
#define ETH_PHY_TYPE  ETH_PHY_LAN8720
#define ETH_PHY_ADDR  0
#define ETH_PHY_MDC  23
#define ETH_PHY_MDIO  18
#define ETH_PHY_POWER 12
#define ETH_CLK_MODE  ETH_CLOCK_GPIO0_OUT
#endif

#include <ETH.h>

static bool eth_connected = false;

// WARNING: onEvent is called from a separate FreeRTOS task (thread)!
void onEvent(arduino_event_id_t event) {
  switch (event) {
    case ARDUINO_EVENT_ETH_START:
      Serial.println("ETH Started");
      // The hostname must be set after the interface is started, but needs
      // to be set before DHCP, so set it from the event handler thread.
      ETH.setHostname("esp32-ethernet");
      break;
    case ARDUINO_EVENT_ETH_CONNECTED: Serial.println("ETH Connected"); break;
    case ARDUINO_EVENT_ETH_GOT_IP:
      Serial.println("ETH Got IP");
      Serial.println(ETH);
      eth_connected = true;
      break;
    case ARDUINO_EVENT_ETH_LOST_IP:
      Serial.println("ETH Lost IP");
      eth_connected = false;
      break;
    case ARDUINO_EVENT_ETH_DISCONNECTED:
      Serial.println("ETH Disconnected");
      eth_connected = false;
      break;
    case ARDUINO_EVENT_ETH_STOP:
      Serial.println("ETH Stopped");
      eth_connected = false;
      break;
    default: break;
  }
}

void testClient(const char *host, uint16_t port) {
  Serial.print("\nconnecting to ");
  Serial.println(host);

  NetworkClient client;
  if (!client.connect(host, port)) {
    Serial.println("connection failed");
    return;
  }
  client.printf("GET / HTTP/1.1\r\nHost: %s\r\n\r\n", host);
  while (client.connected() && !client.available());
  while (client.available()) {
    Serial.write(client.read());
  }

  Serial.println("closing connection\n");
  client.stop();
}

void setup() {
  Serial.begin(115200);
  Network.onEvent(onEvent);
  ETH.begin();
}

void loop() {
  if (eth_connected) {
    testClient("www.google.com", 80);
  }
  delay(1000);
}

If you try the same code and procedure to test as me and if it works the same - then the issue was in the software that you previously used. If you get different results, then most likely the issue is the network equipment. When testing be careful not to connect USB and PoE power at the same time.

Best regards,
Lub/OLIMEX

[A2B]

Hello Lub,

Mea culpa, you right, the problem was we were using old Arduino version to compile the code. When we compiled the code is the new version, there was no problem.

Thanks for your help.

Regards