Wait in setup until ethernet available

esp32_ethernet.cpp

@@ -5,6 +5,8 @@ We use Ethernet, but reuse much of the networking utilities.
 
 #include "esp32_ethernet.hpp"
 
+bool eth_connected = false;
+
 
 void EthernetEvent(WiFiEvent_t event)
 {

esp32_ethernet.hpp

@@ -16,7 +16,7 @@ We use Ethernet, but reuse much of the networking utilities.
 #define ETH_TYPE        ETH_PHY_IP101
 #define ETH_CLK_MODE    ETH_CLOCK_GPIO0_IN
 
-static bool eth_connected = false;
+extern bool eth_connected;
 
 void EthernetEvent(WiFiEvent_t event);
 void connectNetwork();

icbm.ino

@@ -228,6 +228,7 @@ void onMessage(const SNMP::Message *message, const IPAddress remote, const uint1
 }
 
 unsigned long start;
+extern bool eth_connected;
 
 void setup() {
     Serial.begin(115200);
@@ -236,6 +237,11 @@ void setup() {
     snmp.begin(&udp);
     snmp.onMessage(onMessage);
     // Start
+    while (!eth_connected) {
+        Serial.print("-");
+        delay(100);
+    }
+
     start = millis();
     // MPOD
     SNMP::Message *message = mpod.setup();