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Initialize relays at RasPi startup

 

Hello.? My goal is to initialize relays at the startup of the RasPi.? Automatically,, when RasPi starts up would be great.? But I can work with a solution which would be a dashboard button, called for example "initialize relays".? The flow would inject true or false uniquely for each relay.? I have began with Alan's 8 relay flow.? And have a dashboard to uniquely control each relay.?

On the surface I think this would be quite simple to do.? I have done it on Node-Red using inject nodes.? One to inject "false" into all the relays which should be false at start up and another inject node to set "true" for the other relays. I inject the true anf false into the 'rpi - gpio out' nodes.? I just can't get my brain around converting this to a dashboard button that will initialize all the relays with one button push on the dashboard.? Any suggestions on the node(s) I should look at to create this?
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Domenick - WA2GOT? ? 73s
 

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For automatic just use an object node to send Boolean false. Connect it to all the Pi relay GPIO outs. Set the inject to send once after 5 second then interval to never. When you start the Node Red server it will initialize the relays after 5 seconds.?

Dave wo2x

Sent from my waxed string and tin cans.?

On Aug 6, 2021, at 3:23 PM, Domenick Fusca <domenickfusca@...> wrote:

?Hello.? My goal is to initialize relays at the startup of the RasPi.? Automatically,, when RasPi starts up would be great.? But I can work with a solution which would be a dashboard button, called for example "initialize relays".? The flow would inject true or false uniquely for each relay.? I have began with Alan's 8 relay flow.? And have a dashboard to uniquely control each relay.?

On the surface I think this would be quite simple to do.? I have done it on Node-Red using inject nodes.? One to inject "false" into all the relays which should be false at start up and another inject node to set "true" for the other relays. I inject the true anf false into the 'rpi - gpio out' nodes.? I just can't get my brain around converting this to a dashboard button that will initialize all the relays with one button push on the dashboard.? Any suggestions on the node(s) I should look at to create this?
--
Domenick - WA2GOT? ? 73s

 

Domenick

For my GPIO based relay flow, to "initialize" a relay on Node-Red restart, just change one of the "Test" inject nodes to inject one second after start. ?This will position the relay and store he result in context memory. ?I show below an example of using the "false" or open the relay, as an example.

Of note, one of the issues with Raspberry Pi GPIO pins, is the first initial "state" on boot up is undetermined, that is the purpose of waiting one second to initialize the relay. ?Keep in mind, as a result, the relay position could be anything for the first second before the "initialize" inject node fires off.

Alan. WA9WUD
 

Thank You.? That did what I needed, Alan.? And having the screen image was very helpful.? Perhaps you were describing the same thing Dave.? I didn't understand what was meant by an object node.
 

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If you set initialize pin state under gpio it will have the correct state on node red startup regardless of flow.?

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Tormod Brunsby

9. aug. 2021 kl.?21:36 skrev Domenick Fusca <domenickfusca@...>:

?Thank You.? That did what I needed, Alan.? And having the screen image was very helpful.? Perhaps you were describing the same thing Dave.? I didn't understand what was meant by an object node.

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