I've been looking for some time for implementation of pairing two nodes to each other to be able to send messages directly omitting controller. I've seen some other posts suggesting to add this functionality to mysensors core, and proposing base scheme of how it should look like. After some reading I realized that it is not hard to write such code by myself. So I tried my best and now I have what seems to be a working code for two test nodes and a gateway. One of the nodes is modified sketch for binary button the other one is simple one channel relay. I'm not a professional programmer, so code can be optimized more, I guess, and maybe rewritten in better manner.
It's primarily useful for direct communication between a button node (a light switch, or motion sensor) and some relay or other actuator. The key feature is the ability to avoid necessity of controller presence for some simple usage like light switching. Also it provides better reliability in case of controller failure.
Both nodes must have specific pairing button which also serves as "Clear EEPROM" button if pressed before node is powered on. So basically when pairing button is pressed node enters pairing mode for required amount of time (in my case 10 seconds) and sends special message to controller which collects its node and children id's and then waits for 10 seconds for another node to send request in which case it then sends id's vice versa. My code is written only for single button/relay nodes, but it can be made to pair specific child sensors on every node.
Let me know what do you think of it, and if it's useful to anybody.
Binary button code:
// Enable debug prints to serial monitor
#define MY_DEBUG
// Enable and select radio type attached
#define MY_RADIO_NRF24
#include <MySensors.h>
#define CHILD_ID 3
#define SET_BUTTON_PIN 5// Arduino Digital I/O pin for button/reed switch
#define BUTTON_PIN 3
MyMessage msg(CHILD_ID, V_TRIPPED);
bool firstLoop = 1;
bool pairing = 0;
int node_pair=-1;
int sensor_pair=-1;
bool paired=0;
bool lastButState=0;
unsigned long timer1 = 0;
int debounceTime = 1000;
unsigned long timer2 = 0;
int pairWaitTime = 10000;
unsigned long timer3;
int holdTime = 3000;
//Time counter function instead of delay
boolean isTime(unsigned long *timeMark, unsigned long timeInterval) {
if (millis() - *timeMark >= timeInterval) {
*timeMark = millis();
return true;
}
return false;
}
void before()
{
Serial.begin(115200);
Serial.println("Starting node...");
pinMode(SET_BUTTON_PIN, INPUT_PULLUP); //Eneble button pin for detect request for resetting node's EEPROM
bool clr = digitalRead(SET_BUTTON_PIN);
if (!clr) {
Serial.println("Clearing EEPROM");
for (int i=0; i<EEPROM_LOCAL_CONFIG_ADDRESS; i++) {
hwWriteConfig(i,0xFF);
}
//Clearing paired nodes address and paired state
for (int i=245; i<=255; i++) {
hwWriteConfig(i,0xFF);
}
Serial.println("EEPROM is clean");
}
//Reading pairing state from EEPROM and then reading paired nodes id's if paired
paired = loadState(255);
Serial.print("Paired state: ");
Serial.println(paired);
if (paired) {
node_pair = loadState(245);
sensor_pair = loadState(246);
Serial.print("Paired node: ");
Serial.print(node_pair);
Serial.print("-");
Serial.println(sensor_pair);
}
}
void setup()
{
// Setup the buttons
pinMode(BUTTON_PIN, INPUT_PULLUP);
}
void presentation()
{
// Send the sketch version information to the Controller in case node is'nt paired
if (!paired) {
sendSketchInfo("Binary paired button", "1.0");
present(CHILD_ID, S_MOTION);
}
}
// Loop will iterate on changes on the BUTTON_PINs
void loop()
{
bool butState = !digitalRead(BUTTON_PIN);
if (!paired) {
if (firstLoop) {
timer3 = millis(); //Starting delay for pairing button on first loop
}
//If pairing button hold for required amount of seconds initiate pairing process
if (!digitalRead(SET_BUTTON_PIN)) {
if(isTime(&timer3, holdTime)){
Serial.println("Pair button pressed");
pair();
if (!paired) {
Serial.println("Pairing timeout");
}
}
} else {
timer3 = millis();
}
}
//Processing main button press
if (butState != lastButState) {
if (butState) {
lastButState = butState;
if (isTime(&timer1, debounceTime)) {
Serial.println("Button pressed");
//If node is paired to other node send message directly to paired node omitting controller
if (paired) {
MyMessage msg(sensor_pair, V_TRIPPED);
msg.setDestination(node_pair);
Serial.println("Sent message to paired node");
int retry = 0;
while(!send(msg.set(1)) || retry == 10) {
wait(100);
send(msg.set(1));
retry++;
}
} else {
//If not, send message to controller
send(msg.set(1));
Serial.println("Sent message to controller");
}
}
} else {
if (!paired) {
send(msg.set(0));
}
lastButState = butState;
}
}
firstLoop = 0; //Counter for first loop just to know from where to start timer for pairing button hold
}
//Pairing function
void pair()
{
Serial.println("Entering pairing mode");
pairing = 1;
MyMessage pairMsg(244, V_VAR1); //I'm using specific CHILD_ID to be able to filter out pairing requests
send(pairMsg.set("Pair me."), true); //Send any message to gateway
Serial.println("Pair request sent");
//Then we wait some time to recieve paired node id (in my case 10 seconds)
timer2 = millis();
while (!isTime(&timer2, pairWaitTime)) {
wait(1);
if (paired) {
Serial.println("Successfully paired");
break;
}
}
pairing = 0;
}
void receive(const MyMessage &message)
{
//While in pairing mode we'll only process pairing messages
if (pairing) {
if (!message.sender) {
if (message.type == V_VAR2) {
node_pair = atoi(strtok(message.getString(), ";")); //Deconstructing string from gateway, wich must contain id of paired node
Serial.println(node_pair);
sensor_pair = atoi(strtok(NULL, ";")); //...and id of specific sensor on that node, in case there are more than one
Serial.print("Paired with: ");
Serial.println(node_pair);
Serial.println(sensor_pair);
paired=1;
saveState(255, 1);
}
}
}
}
Relay actuator code:
// Enable debug prints to serial monitor
#define MY_DEBUG
// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69
// Enable repeater functionality for this node
//#define MY_REPEATER_FEATURE
#include <MySensors.h>
#define CHILD_ID 1
#define RELAY_PIN 5 // Arduino Digital I/O pin number for relay
#define RELAY_ON 1 // GPIO value to write to turn on attached relay
#define RELAY_OFF 0 // GPIO value to write to turn off attached relay
#define SET_BUTTON_PIN 3
bool relayState;
bool firstLoop = 1;
bool pairing = 0;
int node_pair=-1;
int sensor_pair=-1;
bool paired=0;
bool lastButState=0;
unsigned long timer1 = 0;
int debounceTime = 100;
unsigned long timer2 = 0;
int pairWaitTime = 10000;
unsigned long timer3;
int holdTime = 3000;
unsigned long timer4;
int resendTime = 1500;
MyMessage msg(CHILD_ID,V_LIGHT);
//Time counter function instead delay
boolean isTime(unsigned long *timeMark, unsigned long timeInterval) {
if (millis() - *timeMark >= timeInterval) {
*timeMark = millis();
return true;
}
return false;
}
void before ()
{
Serial.begin(115200);
Serial.println("Starting...");
pinMode(SET_BUTTON_PIN, INPUT_PULLUP);
bool clr = digitalRead(SET_BUTTON_PIN);
if (!clr) {
Serial.println("Clearing EEPROM");
for (int i=0; i<EEPROM_LOCAL_CONFIG_ADDRESS; i++) {
hwWriteConfig(i,0xFF);
}
//Clearing paired nodes address and paired state
for (int i=245; i<=255; i++) {
hwWriteConfig(i,0xFF);
}
Serial.println("EEPROM is clean");
}
//Reading pairing state from EEPROM and then reading paired nodes id's if paired
paired = loadState(255);
Serial.print("Paired state: ");
Serial.println(paired);
if (paired) {
node_pair = loadState(245);
sensor_pair = loadState(246);
Serial.print("Paired node: ");
Serial.print(node_pair);
Serial.print("-");
Serial.println(sensor_pair);
}
pinMode(RELAY_PIN, OUTPUT);
digitalWrite(RELAY_PIN, 1);
delay(1000);
digitalWrite(RELAY_PIN, 0);
// Set relay to last known state (using eeprom storage)
relayState = loadState(CHILD_ID);
digitalWrite(RELAY_PIN, relayState ? RELAY_ON : RELAY_OFF);
}
void setup()
{
}
void presentation()
{
// Send the sketch version information to the gateway and Controller
sendSketchInfo("Relay", "1.0");
present(CHILD_ID, S_LIGHT, "Test light", true);
// Send saved state to gateway (using eeprom storage)
send(msg.set(relayState),true);
}
void loop()
{
if (!paired) {
if (firstLoop) {
timer3 = millis(); //Starting delay for pairing button on first loop
}
//If pairing button hold for required amount of seconds initiate pairing process
if (!digitalRead(SET_BUTTON_PIN)) {
if(isTime(&timer3, holdTime)){
Serial.println("Pair button pressed");
pair();
}
} else {
timer3 = millis();
}
}
firstLoop = 0; //Counter for first loop just to know from where to start timer for pairing button hold
}
void pair()
{
Serial.println("Entering pairing mode");
pairing = 1;
MyMessage pairMsg(244, V_VAR1); //I'm using specific CHILD_ID to be able to filter out pairing requests
send(pairMsg.set("Pair me."), true); //Send any message to gateway
Serial.println("Pair request sent");
//Then we wait some time to recieve paired node id (in my case 10 seconds)
timer2 = millis();
while (!isTime(&timer2, pairWaitTime)) {
wait(1);
if (paired) {
Serial.println("Successfully paired");
break;
}
}
pairing = 0;
Serial.println("Pairing timeout");
}
void receive(const MyMessage &message) {
//While in pairing mode we'll only process pairing messages
if (pairing) {
if (!message.sender) {
if (message.type == V_VAR2) {
node_pair = atoi(strtok(message.getString(), ";")); //Deconstructing string from gateway, wich must contain id of paired node
Serial.println(node_pair);
sensor_pair = atoi(strtok(NULL, ";")); //...and id of specific sensor on that node, in case there are more than one
Serial.print("Paired with: ");
Serial.println(node_pair);
Serial.println(sensor_pair);
paired=1;
saveState(255, 1);
}
}
} else { //Process mesage from gateway
if (message.type == V_LIGHT && !message.sender) {
// Change relay state
relayState = message.getBool();
digitalWrite(RELAY_PIN, relayState ? RELAY_ON : RELAY_OFF);
// Store state in eeprom
saveState(CHILD_ID, relayState);
// Write some debug info
Serial.print("Incoming change. New status:");
Serial.println(relayState);
} else if (message.type == V_TRIPPED && message.sender == node_pair) { //Process message sent directly from paired node
if(isTime(&timer4, resendTime)) {
digitalWrite(RELAY_PIN, relayState ? RELAY_OFF : RELAY_ON);
relayState = relayState ? 0 : 1;
saveState(CHILD_ID, relayState);
send(msg.set(relayState)); //Send changed state to controller, because paired button won't do it
}
}
}
}
Gateway code:
// Enable debug prints to serial monitor
#define MY_DEBUG
// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69
// Set LOW transmit power level as default, if you have an amplified NRF-module and
// power your radio separately with a good regulator you can turn up PA level.
#define MY_RF24_PA_LEVEL RF24_PA_MAX
// Enable serial gateway
#define MY_GATEWAY_SERIAL
// Define a lower baud rate for Arduino's running on 8 MHz (Arduino Pro Mini 3.3V & SenseBender)
#if F_CPU == 8000000L
#define MY_BAUD_RATE 38400
#endif
// Set blinking period
#define MY_DEFAULT_LED_BLINK_PERIOD 300
#include <MySensors.h>
unsigned long currentTime = 0;
int waitTime = 10000;
int node1_addr = 0;
bool node1_addr_present = 0;
int sensor1_addr = 0;
char str1[8];
char str2[8];
bool pairing = 0;
//Messages for answering pairing requests
MyMessage msg(254,V_VAR2);
MyMessage msg2(254,V_VAR2);
//Time counter function instead delay
boolean isTime(unsigned long *timeMark, unsigned long timeInterval) {
if (millis() - *timeMark >= timeInterval) {
*timeMark = millis();
return true;
}
return false;
}
void setup()
{
// Setup locally attached sensors
}
void loop()
{
//We are keeping ids of pairing nodes only for 10 seconds while pairing
if(isTime(¤tTime, waitTime)) {
node1_addr = 0;
node1_addr_present = 0;
}
}
void receive(const MyMessage &message) {
//I used specific message type for filtering out pairing request
if (message.type == V_VAR1) {
Serial.print("Incoming message. Node - ");
Serial.print(message.sender);
Serial.print(message.sensor);
Serial.println(message.getString());
//Check if there was any pairing requests for last 10 seconds, if no begin pairing process
if (!node1_addr_present) {
currentTime = millis();
node1_addr = message.sender;
sensor1_addr = message.sensor;
node1_addr_present = 1;
}
//If there is request from another node send back pairing node ids to each other
else if (message.sender != node1_addr && message.sensor != sensor1_addr) {
snprintf(str2, 7, "%d;%d", message.sender, message.sensor); //Construct message string with node and sensor ids of second node
snprintf(str1, 7, "%d;%d", node1_addr, sensor1_addr); //...and the first one
//print some debug info
Serial.print("First address: ");
Serial.print(str1);
Serial.print("Second address: ");
Serial.print(str2);
//Send answer to nodes
msg.setDestination(message.sender);
send(msg.set(str1), true);
wait(500);
Serial.println("Sent message to second address");
msg2.setDestination(node1_addr);
send(msg2.set(str2), true);
wait(500);
Serial.println("Sent message to first address");
node1_addr = 0;
sensor1_addr = 0;
node1_addr_present = 0;
Serial.println("Pairing finished");
}
}
}
