gort arduino firmata relay on by default

[Andida Syahendar]

After I uploaded the firmata firmware to my UNO, everytime I power it up, the normally opened relay always got turned on immidiately.

How can I make it so it won't turned on immidiately (off by default)? Should I make custom firmata firmware? If so, how do I do that?

Thanks.

[Ron Evans]

Hi @JesusIslam

When the Arduino is first booting up before the firmware loads, you cannot count on the pins being in a consistent state. Normally the circuit you would wire up would accommodate this. For example:

From this useful post:

http://www.electroschematics.com/8975/arduino-control-relay/

Hope that helps!

[Ron Evans]

Hi, @JesusIslam did you get your problem resolved? If you still need further assistance, please reopen this issue. Thanks!