RPi4 question/info

I have looked online for some information on how to get the GPIO to Ignition but I’m a bit lost. I have done programming (C#, C++, Java and Python) so I have I have to write code the shouldn’t be too much of an issue. However, I’m trying to find any current way to get the information on a Raspberry Pi 4 to Ignition. I will let you know that I am new to Ignition itself and this is more as a home learning project.

Thank you for any answers!

Try Node Red. Can control the GPIO pins and can be configured as an OPC UA server that you can configure in the gateway under OPC connections. Or you can do modbus tcp in node red on the pi. Easier to set up if you’re unfamiliar with OPC UA.

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It’d be great if someone versed in Java could write a module to talk directly to the pins :slightly_smiling_face: :slightly_smiling_face:

If pi4j 2.0 ever sees a release me or somebody else around here probably will.


I did some looking into Node Red and other ways of creating an OPC UA server but everything I have found has old out of date commands. However, I found this site on github (https://github.com/OPCFoundation) and would like feedback as this type of programming is new for me. I’m use to Discord bots, basic chat applications that people want to use on a single network to name the more involved programs i have made. Lesser programs is custom made budget tracking. i know a bit low level programming for a lot of you.

download and install OPENPLC from https://www.openplcproject.com/runtime/raspberry-pi/ on to the raspberry pi.

right now I have multiple pi zeros running with it installed. simple program running that just has holding registers mapped to outputs. I also have DS18b20 temp sensors installed and mapped to holding registers. so for about $25 total you get a rasp pi that has 10 input 10 output and temp input that talks ModbusTCP. they are also working on Eth/IP for it.

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You can also run Codesys on the raspberry pi to get access to GPIO (I think). Expensive, but might be worth a shot.

If no one gets to it first, I’ll eventually do a driver based on pigpio, as I noted over in this other thread:

Its worth noting that the driver could be on any gateway that has network access to the RPi, not necessarily on-board. A single gateway could have multiple driver instances pointing into a cloud of RPi’s as if they were “Remote I/O”.


That sounds interesting!
I’m planning on building a weather station with interior temp/humidity monitoring.
The base will be an RPi 4 with the remote sensors using RPi 0s.
All will be connected to a wireless network.
Having the base simply pull the sensor data from the 0s would make things simple!
I hope you get some time to create this driver. :slight_smile: