node-red-contrib-sm-16inpind

[Josov]

I would like to use the Sequent Pi hat for digital input with Node-RED. My question is the following: does the change of an input result in a new message from the node? Or, should I poll the digital input board?

[alexburcea2877]

Hi,
You should poll the board by sending a message to the node.
My advice is to read all inputs with one node (select zero for the channel number) and check for the changing inputs on a function node.

[Josov]

Thank you very much for your honest answer Alexandru. In my project I need to connect buttons to these inputs and for this reason I’d prefer a node generating a message on each new event. Kind regards, Met vriendelijke groeten, Jos Oude Vrielink Borggravevijversstraat 40 3500 Hasselt, België Mobiel: +32 499 71.79.91 Van: Alexandru Burcea ***@***.***> Verzonden: dinsdag 23 mei 2023 11:35 Aan: SequentMicrosystems/16inpind-rpi ***@***.***> CC: Josov ***@***.***>; Author ***@***.***> Onderwerp: Re: [SequentMicrosystems/16inpind-rpi] node-red-contrib-sm-16inpind (Issue #2) Hi, You should poll the board by sending a message to the node. My advice is to read all inputs with one node (select zero for the channel number) and check for the changing inputs on a function node. — Reply to this email directly, view it on GitHub <#2 (comment)> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/AJ733TX6FUQNGTAKEF4IPETXHSACTANCNFSM6AAAAAAYLQODZ4> . You are receiving this because you authored the thread. <https://github.com/notifications/beacon/AJ733TTTXDAWLB34M6T7RJ3XHSACTA5CNFSM6AAAAAAYLQODZ6WGG33NNVSW45C7OR4XAZNMJFZXG5LFINXW23LFNZ2KUY3PNVWWK3TUL5UWJTS45MKNW.gif> Message ID: ***@***.*** ***@***.***> >

[alexburcea2877]

The node can be modified to accommodate this; however, given our busy schedule, I cannot make any promises.
We will consider your suggestion in the future.

Best regards,
Alex.

[Josov]

Dear Alexandru, I need to react promptly on limit switches and user buttons. Polling could cause trouble if I miss an event. It would make my system unreliable. Would it be so much work to adapt the Node and make it event driven? I volunteer for testing documenting etc. Kind regards, Met vriendelijke groeten, Jos Oude Vrielink Independent IT Consultant Borggravevijversstraat 40 3500 Hasselt, België Mobiel: +32 499 717991 Van: Alexandru Burcea ***@***.***> Verzonden: dinsdag 23 mei 2023 12:09 Aan: SequentMicrosystems/16inpind-rpi ***@***.***> CC: Josov ***@***.***>; Author ***@***.***> Onderwerp: Re: [SequentMicrosystems/16inpind-rpi] node-red-contrib-sm-16inpind (Issue #2) The node can be modified to accommodate this; however, given our busy schedule, I cannot make any promises. We will consider your suggestion in the future. Best regards, Alex. — Reply to this email directly, view it on GitHub <#2 (comment)> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/AJ733TUX6GCONCDQPEFKDODXHSECLANCNFSM6AAAAAAYLQODZ4> . You are receiving this because you authored the thread. <https://github.com/notifications/beacon/AJ733TTZVXC6RZNORTZFJOTXHSECLA5CNFSM6AAAAAAYLQODZ6WGG33NNVSW45C7OR4XAZNMJFZXG5LFINXW23LFNZ2KUY3PNVWWK3TUL5UWJTS45QA5A.gif> Message ID: ***@***.*** ***@***.***> >

[alexburcea2877]

Hi,

You can do your own interrupt driven implementation. The card uses Raspberry GPIO26 to signaling the on-change interrupt. So you can use the gpio node to catch the interrupt and the output of this node will feed the input of the 16relind node which reads the state of the inputs. The same as we intend to do inside the node.

Alex.

[Josov]

Dear Alexandru, Thank you very much, I believe this is a good solution, no need to adapt the node. I consider to use 3 or 4 boards each with 4 HV inputs and 4 relays. Will the same principle work using 4 boards as well? Of course, upon interrupt I will nee to read the inputs from all connected boards. Regarding GPIO26 I read from the documentation this pin is used for signalling shut-down (for the HV 4-relay input output board). I do not read about using this pin as interrupt on input change. This will be the configuration, pls let me know if you think I should do different: Kind regards, Met vriendelijke groeten, Jos Oude Vrielink Borggravevijversstraat 40 3500 Hasselt, België Mobiel: +32 499 71.79.91 Van: Alexandru Burcea ***@***.***> Verzonden: dinsdag 23 mei 2023 18:02 Aan: SequentMicrosystems/16inpind-rpi ***@***.***> CC: Josov ***@***.***>; Author ***@***.***> Onderwerp: Re: [SequentMicrosystems/16inpind-rpi] node-red-contrib-sm-16inpind (Issue #2) Hi, You can do your own interrupt driven implementation. The card uses Raspberry GPIO26 to signaling the on-change interrupt. So you can use the gpio node to catch the interrupt and the output of this node will feed the input of the 16relind node which reads the state of the inputs. The same as we intend to do inside the node. Alex. — Reply to this email directly, <#2 (comment)> view it on GitHub, or <https://github.com/notifications/unsubscribe-auth/AJ733TVRIE36CPD4NTDW6E3XHTNP5ANCNFSM6AAAAAAYLQODZ4> unsubscribe. You are receiving this because you authored the thread. <https://github.com/notifications/beacon/AJ733TQRRNCZ2EWGLEMEKULXHTNP5A5CNFSM6AAAAAAYLQODZ6WGG33NNVSW45C7OR4XAZNMJFZXG5LFINXW23LFNZ2KUY3PNVWWK3TUL5UWJTS466V3A.gif> Message ID: < ***@***.***> ***@***.***>

[alexburcea2877]

Hi,

Unfortunately the same principle will not work well with the 4-relays cards. There is a firmware bug on that cards so they will signaling the GPIO26 on the falling edge of the input, this means that you can use it in reverse logic manner. The card will signaling when one input is deenergized so if you need to catch the "logical 1", you can not. On the other hand the 4-relays card has a lot more features, you can count the transitions and measure the frequency of an input signal.
I guess 16-inputs is more suitable for your application because you have to do a single read operation when the interrupt is raised. I must tell you that all our cards with interrupt use the same GPIO26 for the interrupt generation so you have to ask all the cards in the system to see which one generates the interrupt.

Alex.