RF24Ethernet - TCP/IP over RF24Network v1.6.15
TMRh20 - Pushing the practical limits of RF24 modules
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This example demonstrates how to use an Arduino as a gateway to a SLIP enabled device.

* RF24Ethernet Serial Gateway Example using SLIP *
* This example will allow RF24Ethernet to be used with any device capable of utilizing the SLIP protocol
* When using SLIP, there are 3 main differences:
* 1. The RF24Mesh layer must be used to provide MAC/IP translation
* 2. For child nodes (NOT this master/gateway node) The specified RF24Mesh nodeID must be the same as the last octet of the IP
* ie: IP: NodeId must be 2
* 3. The RF24Ethernet library must be configured for TUN
* a: Open the uip_conf.h file, set the #define UIP_CONF_LLH_LEN 0
* The following commands must be run on the Linux device to enable slip
* 1. On RPi, cd /dev
* 2. Type 'ls' , note the ttyUSB<X> devices
* 3. Connect your Arduino
* 4. Type 'ls' and look for a new device ttyUSB<X> where <X> is a number
* 5. Run sudo modprobe slip
* 6. Run sudo slattach -L -s 115200 -p slip /dev/ttyUSB<X> &
* 7. Note the & at the end of the previous command. Without it, slattach will appear to hang and CTRL+C will exit.
* 7. Run ifconfig , note the sl<X> device
* 8. Run sudo ifconfig sl<X>
* 9. Run sudo route add -net gw
* 10. The gateway is now up and running. Active RF24Ethernet nodes should be pingable.
Note: If using an ip of for the gateway, the commands are very similar:
ie: sudo route add -net gw
* RF24Ethernet uses the uIP stack by Adam Dunkels <adam@sics.se>
* This example demonstrates how to configure a sensor node to act as a webserver and
* allows a user to control a connected LED by clicking links on the webpage
* The requested URL is used as input, to determine whether to turn the LED off or on
#include <SPI.h>
#include <RF24.h>
#include <RF24Network.h>
#include <RF24Mesh.h>
RF24 radio(7, 8);
RF24Network network(radio);
RF24Mesh mesh(radio, network);
#define LED_TXRX // Flash LED on SLIP device TX or RX
#define SLIP_DEBUG // Will delay and flash LEDs if unable to find a node by IP address ( node needs to reconnect via RF24Mesh )
// Define the LED pin for the above two options
#define DEBUG_LED_PIN A3
// NOTE: IMPORTANT this should be set to the same value as the UIP_BUFSIZE and
// the MAX_PAYLOAD_SIZE in RF24Network. The default is 120 bytes
uint8_t slip_buf[UIP_BUFFER_SIZE]; // MSS + TCP Header Length
//Function to send incoming network data to the SLIP interface
void networkToSLIP();
void setup() {
// Set this to the master node (nodeID 0)
// Use the serial port as the SLIP device
// LED stuff
#if defined(SLIP_DEBUG)
digitalWrite(DEBUG_LED_PIN, HIGH);
digitalWrite(DEBUG_LED_PIN, LOW);
uint32_t active_timer = 0;
void loop() {
// Provide RF24Network addresses to connecting & reconnecting nodes
if (millis() > 10000) {
//Ensure any incoming user payloads are read from the buffer
while (network.available()) {
RF24NetworkHeader header;
network.read(header, 0, 0);
// Handle external (TCP) data
// Note: If not utilizing RF24Network payloads directly, users can edit the RF24Network_config.h file
// and uncomment #define DISABLE_USER_PAYLOADS. This can save a few hundred bytes of RAM.
if (mesh.update() == EXTERNAL_DATA_TYPE) {
// Poll the SLIP device for incoming data
//uint16_t len = slipdev_poll();
uint16_t len;
if ((len = slipdev_poll()) > 0) {
if (len > MAX_PAYLOAD_SIZE) {
RF24NetworkHeader header(01, EXTERNAL_DATA_TYPE);
uint8_t meshAddr;
// Get the last octet of the destination IP address
uint8_t lastOctet = slip_buf[19];
//Convert the IP into an RF24Network Mac address
if ((meshAddr = mesh.getAddress(lastOctet)) > 0) {
// Set the RF24Network address in the header
header.to_node = meshAddr;
#if defined(LED_TXRX)
digitalWrite(DEBUG_LED_PIN, HIGH);
network.write(header, &slip_buf, len);
#if defined(LED_TXRX)
digitalWrite(DEBUG_LED_PIN, LOW);
} else {
// If nodeID/IP not found in address list, the node would need to renew its address
// Flash the LED 3 times slowly
void networkToSLIP() {
RF24NetworkFrame* frame = network.frag_ptr;
size_t size = frame->message_size;
uint8_t* pointer = frame->message_buffer;
slipdev_send(pointer, size);
//digitalWrite(DEBUG_LED_PIN, !digitalRead(DEBUG_LED_PIN));
void flashLED() {
#if defined(SLIP_DEBUG)
digitalWrite(DEBUG_LED_PIN, HIGH);
digitalWrite(DEBUG_LED_PIN, LOW);
digitalWrite(DEBUG_LED_PIN, HIGH);
digitalWrite(DEBUG_LED_PIN, LOW);
digitalWrite(DEBUG_LED_PIN, HIGH);
digitalWrite(DEBUG_LED_PIN, LOW);