Thanks to everyone who helped! now it would be interesting again, if it also works with the latest SAMD and arduino ide versions...?! has somebody already tested it/ been running?

To the Sensebender Board with W5100+NRF24:

• Sensebender can be flashed via Arduino IDE: Bootloader and Sketch
• Note versions (work):
  Arduino IDE 1.6.13
  Arduino AVR 1.6.18
  Arduino SAMD 1.6.12
  MySensors SAMD 1.0.5
  MySensors Lib 2.3.1
• Installed is an Atmel "ATSAMD21J18A-AU".
• Windows 10 does not recognize the serial port after a few flashes (native USB ATSAMD21J18A-AU). Then the PC must be restarted.
• the bootloader has to be flashed via SWD interface (e.g. with Atmel JtagICE3):
  -> install Atmel Studio 7 (for JtagICE3 drivers) and erase chip
  -> Connect the pins of the JTAGICE3 to Sensebender:
  JTAGICE3: ARM SWD Pin:
  Pin 1 (TCK) SWDCLK
  Pin 2 (GND) GND
  Pin 4 (VTG) VCC
  Pin 5 (TMS) SWDIO
  Pin 6 (nSRST) nRESET
  -> bootloader about Ardunio IDE flash: Programmer "Atmel EDBG or Atmel Sam ICE"
  -> usb port should now be found automatically (windows 10 has drivers already integrated, install win7.8 driver from MySensors)
• sketch normal about arduino ide and port selection flashes

My working Sensebender W5100+NRF24 sketch:

/*
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2018 Sensnology AB
 * Full contributor list: https://github.com/mysensors/MySensors/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Henrik EKblad
 * Contribution by a-lurker and Anticimex,
 * Contribution by Norbert Truchsess <norbert.truchsess@t-online.de>
 * Contribution by Tomas Hozza <thozza@gmail.com>
 *
 *
 * DESCRIPTION
 * The EthernetGateway sends data received from sensors to the ethernet link.
 * The gateway also accepts input on ethernet interface, which is then sent out to the radio network.
 *
 * The GW code is designed for Arduino 328p / 16MHz.  ATmega168 does not have enough memory to run this program.
 *
 * LED purposes:
 * - To use the feature, uncomment MY_DEFAULT_xxx_LED_PIN in the sketch below
 * - RX (green) - blink fast on radio message received. In inclusion mode will blink fast only on presentation received
 * - TX (yellow) - blink fast on radio message transmitted. In inclusion mode will blink slowly
 * - ERR (red) - fast blink on error during transmission error or receive crc error
 *
 * See http://www.mysensors.org/build/ethernet_gateway for wiring instructions.
 *
 */

//@riss
// Define sketch version
#define SKETCH_VERSION "0.4"
//@riss

// Enable debug prints to serial monitor
#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_RF24
//#define MY_RADIO_NRF5_ESB
//#define MY_RADIO_RFM69
//#define MY_RADIO_RFM95

// Enable gateway ethernet module type
#define MY_GATEWAY_W5100
#define MY_GATEWAY_MAX_CLIENTS  3

// W5100 Ethernet module SPI enable (optional if using a shield/module that manages SPI_EN signal)
//#define MY_W5100_SPI_EN 4

// Enable Soft SPI for NRF radio (note different radio wiring is required)
// The W5100 ethernet module seems to have a hard time co-operate with
// radio on the same spi bus.
#if !defined(MY_W5100_SPI_EN) && !defined(ARDUINO_ARCH_SAMD)
#define MY_SOFTSPI
#define MY_SOFT_SPI_SCK_PIN 14
#define MY_SOFT_SPI_MISO_PIN 16
#define MY_SOFT_SPI_MOSI_PIN 15
#endif

// When W5100 is connected we have to move CE/CSN pins for NRF radio
#ifndef MY_RF24_CE_PIN
#define MY_RF24_CE_PIN 5
#endif
#ifndef MY_RF24_CS_PIN
#define MY_RF24_CS_PIN 6
#endif

// Enable UDP communication
//#define MY_USE_UDP  // If using UDP you need to set MY_CONTROLLER_IP_ADDRESS below

// Enable MY_IP_ADDRESS here if you want a static ip address (no DHCP)
#define MY_IP_ADDRESS 192,168,1,38

// If using static ip you can define Gateway and Subnet address as well
#define MY_IP_GATEWAY_ADDRESS 192,168,1,1
#define MY_IP_SUBNET_ADDRESS 255,255,255,0

// Renewal period if using DHCP
//#define MY_IP_RENEWAL_INTERVAL 60000

// The port to keep open on node server mode / or port to contact in client mode
#define MY_PORT 5003

// Controller ip address. Enables client mode (default is "server" mode).
// Also enable this if MY_USE_UDP is used and you want sensor data sent somewhere.
//#define MY_CONTROLLER_IP_ADDRESS 192, 168, 178, 254

// The MAC address can be anything you want but should be unique on your network.
// Newer boards have a MAC address printed on the underside of the PCB, which you can (optionally) use.
// Note that most of the Arduino examples use  "DEAD BEEF FEED" for the MAC address.
#define MY_MAC_ADDRESS 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED

// Enable inclusion mode
#define MY_INCLUSION_MODE_FEATURE
// Enable Inclusion mode button on gateway
//#define MY_INCLUSION_BUTTON_FEATURE
// Set inclusion mode duration (in seconds)
#define MY_INCLUSION_MODE_DURATION 60
// Digital pin used for inclusion mode button
//#define MY_INCLUSION_MODE_BUTTON_PIN  3

// Set blinking period
#define MY_DEFAULT_LED_BLINK_PERIOD 300

// Flash leds on rx/tx/err
// Uncomment to override default HW configurations
//#define MY_DEFAULT_ERR_LED_PIN 7  // Error led pin
//#define MY_DEFAULT_RX_LED_PIN  8  // Receive led pin
//#define MY_DEFAULT_TX_LED_PIN  9  // Transmit led pin

#if defined(MY_USE_UDP)
#include <EthernetUdp.h>
#endif
#include <Ethernet.h>
#include <MySensors.h>

//@riss
#include <SD.h>
#include <drivers/ATSHA204/ATSHA204.cpp>

Sd2Card card;

#define EEPROM_VERIFICATION_ADDRESS 0x01

static uint8_t num_of_leds = 5;
static uint8_t leds[] = {LED_BLUE, LED_RED, LED_GREEN, LED_YELLOW, LED_ORANGE};
//@riss

void setup()
{
	// Setup locally attached sensors
 sleep(250);      // wait for the W5100
}

void presentation()
{
	// Present locally attached sensors here
}

void loop()
{
	// Send locally attached sensors data here
}




//@riss
void preHwInit()
{

  pinMode(MY_SWC1, INPUT_PULLUP);
  pinMode(MY_SWC2, INPUT_PULLUP);
  if (digitalRead(MY_SWC1) && digitalRead(MY_SWC2)) {
    return;
  }

  uint8_t tests = 0;

  for (int i=0; i< num_of_leds; i++) {
    pinMode(leds[i], OUTPUT);
  }
  if (digitalRead(MY_SWC1)) {
    uint8_t led_state = 0;
    while (!Serial) {
      digitalWrite(LED_BLUE, led_state);
      led_state ^= 0x01;
      delay(500);
    } // Wait for USB to be connected, before spewing out data.
  }
  digitalWrite(LED_BLUE, LOW);
  if (Serial) {
    Serial.println("Sensebender GateWay test routine");
    Serial.print("MySensors core version : ");
    Serial.println(MYSENSORS_LIBRARY_VERSION);
    Serial.print("GateWay sketch version : ");
    Serial.println(SKETCH_VERSION);
    Serial.println("----------------------------------");
    Serial.println();
  }
  if (testSha204()) {
    digitalWrite(LED_GREEN, HIGH);
    tests++;
  }
  if (testSDCard()) {
    digitalWrite(LED_YELLOW, HIGH);
    tests++;
  }

  if (testEEProm()) {
    digitalWrite(LED_ORANGE, HIGH);
    tests++;
  }
  if (testAnalog()) {
    digitalWrite(LED_BLUE, HIGH);
    tests++;
  }
  if (tests == 4) {
    while(1) {
      for (int i=0; i<num_of_leds; i++) {
        digitalWrite(leds[i], HIGH);
        delay(200);
        digitalWrite(leds[i], LOW);
      }
    }
  } else {
    while (1) {
      digitalWrite(LED_RED, HIGH);
      delay(200);
      digitalWrite(LED_RED, LOW);
      delay(200);
    }
  }

}

bool testSha204()
{
  uint8_t rx_buffer[SHA204_RSP_SIZE_MAX];
  uint8_t ret_code;
  if (Serial) {
    Serial.print("- > SHA204 ");
  }
  atsha204_init(MY_SIGNING_ATSHA204_PIN);
  ret_code = atsha204_wakeup(rx_buffer);

  if (ret_code == SHA204_SUCCESS) {
    ret_code = atsha204_getSerialNumber(rx_buffer);
    if (ret_code != SHA204_SUCCESS) {
      if (Serial) {
        Serial.println(F("Failed to obtain device serial number. Response: "));
      }
      Serial.println(ret_code, HEX);
    } else {
      if (Serial) {
        Serial.print(F("Ok (serial : "));
        for (int i=0; i<9; i++) {
          if (rx_buffer[i] < 0x10) {
            Serial.print('0'); // Because Serial.print does not 0-pad HEX
          }
          Serial.print(rx_buffer[i], HEX);
        }
        Serial.println(")");
      }
      return true;
    }
  } else {
    if (Serial) {
      Serial.println(F("Failed to wakeup SHA204"));
    }
  }
  return false;
}

bool testSDCard()
{
  if (Serial) {
    Serial.print("- > SD CARD ");
  }
  if (!card.init(SPI_HALF_SPEED, MY_SDCARD_CS)) {
    if (Serial) {
      Serial.println("SD CARD did not initialize!");
    }
  } else {
    if (Serial) {
      Serial.print("SD Card initialized correct! - ");
      Serial.print("type detected : ");
      switch(card.type()) {
      case SD_CARD_TYPE_SD1:
        Serial.println("SD1");
        break;
      case SD_CARD_TYPE_SD2:
        Serial.println("SD2");
        break;
      case SD_CARD_TYPE_SDHC:
        Serial.println("SDHC");
        break;
      default:
        Serial.println("Unknown");
      }
    }
    return true;
  }
  return false;
}

bool testEEProm()
{
  uint8_t eeprom_d1, eeprom_d2;
  SerialUSB.print(" -> EEPROM ");
  eeprom_d1 = hwReadConfig(EEPROM_VERIFICATION_ADDRESS);
  delay(500);
  eeprom_d1 = ~eeprom_d1; // invert the bits
  hwWriteConfig(EEPROM_VERIFICATION_ADDRESS, eeprom_d1);
  delay(500);
  eeprom_d2 = hwReadConfig(EEPROM_VERIFICATION_ADDRESS);
  if (eeprom_d1 == eeprom_d2) {
    SerialUSB.println("PASSED");
    hwWriteConfig(EEPROM_VERIFICATION_ADDRESS, ~eeprom_d1);
    return true;
  }
  SerialUSB.println("FAILED!");
  return false;
}

bool testAnalog()
{
  int bat_detect = analogRead(MY_BAT_DETECT);
  Serial.print("-> analog : ");
  Serial.print(bat_detect);
  if (bat_detect < 400 || bat_detect > 650) {
    Serial.println(" Failed");
    return false;
  }
  Serial.println(" Passed");
  return true;
}
//@riss

ok, the weekend has brought a lot of information... both problems have been solved:
To the Arduino Nano+W5100+NRF24:

• Note versions:
  Clean Install (delete Dirs: ".../Documents/Arduino", "AppData", "Arduino IDE") before compiling:
  Arduino IDE 1.6.13
  Arduino AVR 1.6.18
  Arduino SAMD 1.6.12
  MySensors SAMD 1.0.5
  MySensors Lib 2.3.1

• if no W5100 is attached, then 0.0.0.0 comes in the log

• Both GNDs of the W5100 must be connected!

• Voltage with +5V, if voltage transformer present

• optional: fix bug of W5100: https://arduinodiy.wordpress.com/2017/04/12/the-w5100-bug/

• successful log Nano_5V_16Mhz+W5100+NRF24:
  0 MCO:BGN:INIT GW,CP=RNNGA---,REL=255,VER=2.3.1
  4 TSM:INIT
  5 TSF:WUR:MS=5000
  11 TSM:INIT:TSP OK
  13 TSM:INIT:GW MODE
  15 TSM:READY:ID=0,PAR=0,DIS=0
  17 MCO:REG:NOT NEEDED
  320 GWT:TIN:IP=128.168.1.38
  1323 MCO:BGN:STP
  1325 MCO:SLP:MS=250,SMS=0,I1=255,M1=255,I2=255,M2=255,M2=255
  1330 !MCO:SLP:REP
  1332 TSM:READY:NWD REQ
  1369 TSF:MSG:SEND,0-0-255-255,s=255,c=3,t=20,pt=0,l=0,sg=0,ft=0,st=OK:
  1581 MCO:BGN:INIT OK,TSP=1

• power consumption Nano_5V_16Mhz+W5100+NRF24: 250mA

• operate the W5100 with its own +5V power supply!

With 2kB SRAM, the Arduino Nano meets the minimum requirements for an ETHERNET(!) gateway (serial gateway is no problem). It can happen from time to time that the W5100 is not responsive for a short time because the nano does not follow. It is best to deactivate MY_DEBUG or use a mega with 8kB memory.

My working Nano+W5100+NRF24 Sketch:

/*
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2018 Sensnology AB
 * Full contributor list: https://github.com/mysensors/MySensors/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Henrik EKblad
 * Contribution by a-lurker and Anticimex,
 * Contribution by Norbert Truchsess <norbert.truchsess@t-online.de>
 * Contribution by Tomas Hozza <thozza@gmail.com>
 *
 *
 * DESCRIPTION
 * The EthernetGateway sends data received from sensors to the ethernet link.
 * The gateway also accepts input on ethernet interface, which is then sent out to the radio network.
 *
 * The GW code is designed for Arduino 328p / 16MHz.  ATmega168 does not have enough memory to run this program.
 *
 * LED purposes:
 * - To use the feature, uncomment MY_DEFAULT_xxx_LED_PIN in the sketch below
 * - RX (green) - blink fast on radio message received. In inclusion mode will blink fast only on presentation received
 * - TX (yellow) - blink fast on radio message transmitted. In inclusion mode will blink slowly
 * - ERR (red) - fast blink on error during transmission error or receive crc error
 *
 * See http://www.mysensors.org/build/ethernet_gateway for wiring instructions.
 *
 */

// Enable debug prints to serial monitor
//#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_RF24
//#define MY_RADIO_NRF5_ESB
//#define MY_RADIO_RFM69
//#define MY_RADIO_RFM95

// Enable gateway ethernet module type
#define MY_GATEWAY_W5100
#define MY_GATEWAY_MAX_CLIENTS  3

// W5100 Ethernet module SPI enable (optional if using a shield/module that manages SPI_EN signal)
//#define MY_W5100_SPI_EN 4

// Enable Soft SPI for NRF radio (note different radio wiring is required)
// The W5100 ethernet module seems to have a hard time co-operate with
// radio on the same spi bus.
#if !defined(MY_W5100_SPI_EN) && !defined(ARDUINO_ARCH_SAMD)
#define MY_SOFTSPI
#define MY_SOFT_SPI_SCK_PIN 14
#define MY_SOFT_SPI_MISO_PIN 16
#define MY_SOFT_SPI_MOSI_PIN 15
#endif

// When W5100 is connected we have to move CE/CSN pins for NRF radio
#ifndef MY_RF24_CE_PIN
#define MY_RF24_CE_PIN 5
#endif
#ifndef MY_RF24_CS_PIN
#define MY_RF24_CS_PIN 6
#endif

// Enable UDP communication
//#define MY_USE_UDP  // If using UDP you need to set MY_CONTROLLER_IP_ADDRESS below

// Enable MY_IP_ADDRESS here if you want a static ip address (no DHCP)
#define MY_IP_ADDRESS 192,168,1,38

// If using static ip you can define Gateway and Subnet address as well
#define MY_IP_GATEWAY_ADDRESS 192,168,1,1
#define MY_IP_SUBNET_ADDRESS 255,255,255,0

// Renewal period if using DHCP
//#define MY_IP_RENEWAL_INTERVAL 60000

// The port to keep open on node server mode / or port to contact in client mode
#define MY_PORT 5003

// Controller ip address. Enables client mode (default is "server" mode).
// Also enable this if MY_USE_UDP is used and you want sensor data sent somewhere.
//#define MY_CONTROLLER_IP_ADDRESS 192, 168, 178, 254

// The MAC address can be anything you want but should be unique on your network.
// Newer boards have a MAC address printed on the underside of the PCB, which you can (optionally) use.
// Note that most of the Arduino examples use  "DEAD BEEF FEED" for the MAC address.
#define MY_MAC_ADDRESS 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED

// Enable inclusion mode
#define MY_INCLUSION_MODE_FEATURE
// Enable Inclusion mode button on gateway
//#define MY_INCLUSION_BUTTON_FEATURE
// Set inclusion mode duration (in seconds)
#define MY_INCLUSION_MODE_DURATION 60
// Digital pin used for inclusion mode button
//#define MY_INCLUSION_MODE_BUTTON_PIN  3

// Set blinking period
#define MY_DEFAULT_LED_BLINK_PERIOD 300

// Flash leds on rx/tx/err
// Uncomment to override default HW configurations
//#define MY_DEFAULT_ERR_LED_PIN 7  // Error led pin
//#define MY_DEFAULT_RX_LED_PIN  8  // Receive led pin
//#define MY_DEFAULT_TX_LED_PIN  9  // Transmit led pin

#if defined(MY_USE_UDP)
#include <EthernetUdp.h>
#endif
#include <Ethernet.h>
#include <MySensors.h>

void setup()
{
	// Setup locally attached sensors
 sleep(250);    // Optional, if W5100 is rebooting
}

void presentation()
{
	// Present locally attached sensors here
}

void loop()
{
	// Send locally attached sensors data here
}

@tbowmo yes, it is the standard "SensebenderGatewaySerial" sketch.
i try to reinstall the arduino ide completely on the weekend and use older versions. it is worth a try...

Okay, thanks for the clarification.
i changed the processor because the USB interface was not recognized under windows and i couldn't program the board anymore. leds were lit but, so i thought that the samd must be broken.
the new one shows the same behavior after flashing with mysensors 2.3.1 ... so it must be somewhere due to the software.

can you please initiate the change to the "platform.txt" (see https://forum.mysensors.org/post/96909)?

has anyone managed to get an arduino nano running with NRF and W5100 as ethernet gateway? mine won't even accept the IP address (should be 192.168.1.110) after a successful sketch:

 MCO:BGN:INIT GW,CP=RNNGA---,REL=255,VER=2.3.1<\n>
4 TSM:INIT<\n>
5 TSF:WUR:MS=0<\n>
11 TSM:INIT:TSP OK<\n>
13 TSM:INIT:GW MODE<\n>
15 TSM:READY:ID=0,PAR=0,DIS=0<\n>
17 MCO:REG:NOT NEEDED<\n>
580 GWT:TIN:IP=0.0.0.0<\n>
1582 MCO:BGN:STP<\n>
1584 MCO:BGN:INIT OK,TSP=1<\n>
1586 TSM:READY:NWD REQ<\n>
1624 TSF:MSG:SEND,0-0-255-255,s=255,c=3,t=20,pt=0,l=0,sg=0,ft=0,st=OK:<\n>

i just found out that the platform.txt is not correct/outdated. The file "...\Arduino15\packages\MySensors\hardware\samd\1.0.5\platform.txt"
Line 148 should be changed from

openocd-0.9.0-arduino5-static.path 

to

openocd-0.9.0-arduino6-static.path

can one of the mysensors samd board 1.0.5 please change that?

ok, I flashed the bootloader and now LED5 (D5) is lit permanently. A new USB port is also not recognized.
the fuse settings were probably not set either. do I still have to set them or don't I need them at sensebender gw?
but i need the USB port, otherwise i can't transfer sketches.
if I transfer sketches via SWD nothing happens after the upload.

can anyone tell me how to flash the sensebender board (Atmel ATSAMD21J18A) with openocd and an Atmel JtagIce3 running on windows? i have a batch file, but it returns an error.

Batch file:

openocd\bin\openocd --debug 4 --log_output log.txt -d0 -s openocd/share/openocd/scripts/ -f arduino_zero.cfg -c "telnet_port disabled; init; halt; at91samd bootloader 0; program {{%1}} verify reset;shutdown"

log_file:

Debug: 17 12 command.c:145 script_debug(): command - ocd_command ocd_command type ocd_debug_level 0
Debug: 18 12 command.c:145 script_debug(): command - debug_level ocd_debug_level 0
debug_level: 0
adapter speed: 500 kHz
adapter_nsrst_delay: 100
cortex_m reset_config sysresetreq
target state: halted
target halted due to debug-request, current mode: Thread 
xPSR: 0x81000000 pc: 0x00005460 msp: 0x20007fb8
target state: halted
target halted due to debug-request, current mode: Thread 
xPSR: 0x81000000 pc: 0x000005e8 msp: 0x20007ffc
** Programming Started **
auto erase enabled
Runtime Error: embedded:startup.tcl:454: ** Programming Failed **
in procedure 'program' 
in procedure 'program_error' called at file "embedded:startup.tcl", line 510
at file "embedded:startup.tcl", line 454

Yes, on every radio.
tomorrow I'll try different tests and then report back