# Set and Get Variables & Time from Arduino Projects to Node-Red
**URL:** https://discourse.nodered.org/t/set-and-get-variables-time-from-arduino-projects-to-node-red/94083
**Category:** Share Your Projects
**Tags:** function-node, mqtt
**Created:** [21 December 2024 14:46 UTC](https://discourse.nodered.org/t/set-and-get-variables-time-from-arduino-projects-to-node-red/94083 "2024-12-21T14:46:10Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@ajaybnl](https://discourse.nodered.org/u/ajaybnl)
#### Post date: [21 December 2024 14:46 UTC](https://discourse.nodered.org/t/set-and-get-variables-time-from-arduino-projects-to-node-red/94083/1 "2024-12-21T14:46:10Z")
You can save variables in Node-red Flow/Storage Data using Arduino based boards like ESP8266 , ESP32, and so on.
**Concept:**
Send message to node/variable to store
publish to TOPIC + /$get to get stored data
**Example:**
To Set data, send mqtt messages like : Topic: "_home/sensor1/variable1_" -\> Payload: "_1_"
To Get data, subscribe to "_home/sensor1/variable1_"
and publish message "_home/sensor1/variable1/$get_" -\> Payload : " **ANY**"
The data will come in subscribed topic.
You can also get TIMESTAMP using same function just replace "variable1" with "time" using same method written above.
add a mqtt in (with your sensor root topic like "home/sensor1/#") and mqtt out (without topic) to output
**Note:**
The Time is in IST. To convert to Your Host Time Remove This Part : " _+ IST\_offset;_"
**The Function Node Code :**
```auto
var topic = msg.topic;
var payload = msg.payload;
var isget = false;
//IS GET REQUEST
if (topic.endsWith("/$get")) {
topic = topic.replace("/$get", "");
isget = true;
}
//Extract sensor_var
var topicParts = topic.split('/');
var nodename = topicParts[1];
var command = topicParts[topicParts.length - 1];
var variablename = nodename + "_" + command;
//GET REQUEST
if (isget) {
if (topic.endsWith("/time")) {
var date = new Date();
var IST_offset = 5.5 * 60 * 60 * 1000;
var IST_timestamp_ms = date.getTime() + IST_offset;
var IST_timestamp_sec = Math.floor(IST_timestamp_ms / 1000); // Convert to seconds (32-bit Unix timestamp)
msg.topic = topic;
msg.payload = IST_timestamp_sec;
return msg;
} else if (topic.endsWith("status") || topic.startsWith("reboot")) {
//STATUS OR REBOOT
//IGNORE
} else {
//TIME
// ALL TOPICS
let da = flow.get(variablename);
if (da == undefined) da = 0;
msg.topic = topic;
msg.payload = da;
return msg;
}
} else {
//SAVE
if (topic.endsWith("status") || topic.endsWith("/time") || topic.startsWith("reboot")) {
//STATUS TIME OR REBOOT
//IGNORE
} else {
//ALL OTHER
flow.set(variablename, payload);
}
}
```
---
### Author:  [@marcus-j-davies](https://discourse.nodered.org/u/marcus-j-davies)
#### Post date: [21 December 2024 14:52 UTC](https://discourse.nodered.org/t/set-and-get-variables-time-from-arduino-projects-to-node-red/94083/2 "2024-12-21T14:52:39Z")
@ajaybnl
Please don't use tags, that are not associated to your content.
`node-red-dashboard` removed
Thank you
---
### Author:  [@jbudd](https://discourse.nodered.org/u/jbudd)
#### Post date: [21 December 2024 16:11 UTC](https://discourse.nodered.org/t/set-and-get-variables-time-from-arduino-projects-to-node-red/94083/3 "2024-12-21T16:11:13Z")
Thanks for sharing that @ajaybnl
I am confused which end of the Arduino - Node-red link is sending which message and when.
Can you share a screen capture which includes your mqtt-in and mqtt-out nodes to make it clearer?
---
### Author:  [@ajaybnl](https://discourse.nodered.org/u/ajaybnl)
#### Post date: [23 December 2024 04:38 UTC](https://discourse.nodered.org/t/set-and-get-variables-time-from-arduino-projects-to-node-red/94083/4 "2024-12-23T04:38:43Z")
**From Node-red**
**From ESP8266 Arduino**
Using Library EspMqttClient
**Publish Get Variable from Node-Red**
_Timer for incremental responsemode after 2 seconds (to get a window for receiving a mqtt message)_
```auto
if ((((millis() - timer3))) >= 2000)
{
timer3 = millis();
if (client.isConnected())
{
if (responsemode == 0)
{
// Get variable1 from Node-Red
client.publish("home/sensor/variable1/$get", "0");
//to increment the queue
responsemode++;
}
else if (responsemode == 1)
{
// Get Time from Node-Red
client.publish("home/sensor/time/$get", "0");
responsemode++;
}
}
}
```
**Subscribing Mqtt code**
```auto
client.subscribe("home/sensor/variable1", [](const String &payload){
if (payload.length() > 0) {
int val = payload.toInt();
//Global variable
variable1 = val;
} });
//----------
// Time
client.subscribe("home/sensor/time", [](const String &payload){
if (payload.length() > 0) {
unsigned long timestamp = payload.toInt();
//TimeLib (Set Timestamp)
setTime(timestamp);
} });
}
```