š¬ What's all the fuss about?
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Hello! Forgive me if I bother you, or if I ask some stupidity ... but I wanted to ask you something I can not find anywhere.
I already have a Relay node and a Sensor Node with a gateway running. I am using MYSController. Everything works OK.
I have concerns about some code syntax.
I can not finish understanding regarding the reading or writing of states in a binary device the syntax:state? RELAY_ON: RELAY_OFF
or
state? "true": "false"What does the "?" Mean. How should I understand that line? Because there are times when it appears inverted:
state? RELAY_OFF: RELAY_ON
or
state? "false": "true"Thank you!
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@matias_sams said in š¬ What's all the fuss about?:
state? "true": "false"
It's known in C language as conditional operator
https://en.wikipedia.org/wiki/%3F:#C -
To add to the previous answer, in the relay example sketch, ? is used to handle that some relays are active low, some are active high.
From the sketch:
#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 -
!!!
Thank you very much community, you are great! -
Hi, I'm working on project of mobile app to measure the CO2, LPG gas , Smog through MQ135 and MQ7 sensors. Kindly help me what should I do??
Give me suggestions....Thank you -
Hi, I'm working on project of mobile app to measure the CO2, LPG gas , Smog through MQ135 and MQ7 sensors. Kindly help me what should I do??
Give me suggestions....Thank youWelcome to the MySensors forum @talhayounis
Th best way to get started with MySensors is to first read the getting started guide. Then you can move on to https://www.mysensors.org/build/gas which has an example sketch to use with MQ135 and MQ7.
The best way is usually to get a gateway and a simple node running, and then expand from that.
