When you need to control relays , usually you use a raspberryPi. Mostly the pi works great, however, when you need an all-in-one tool to control realys communicate with 485 sensors read data from zigbee sensors
What you really need is a mighty netGate PN6400
And the Node-red node is simple to use as pictured below.
We have done plenty of work around running Node-RED on ubuntu device aka our netGate.
Our aim is to introduce the PN6400 series products to users, just like ESP has done.
At this time, we are looking for professional users to test our products and feedback their experience to us in order to continue improving the product series.
In my experience, ubuntu 16.04LTS may widely work in embedded system applications.
Which is actually a problem and will restrict sales into many organisations. For example, in the UK, many organisations require that software and firmware on devices must remain current for the life of the product. That means that it must be possible to update it for the expected usage life, keeping all software at currently supported versions.
This is an area of growing awareness as more and more organisations end up with targeted malware that enters via poorly maintained IoT devices.
What kind of testing are you looking for? In the past I've worked testing industrial hardware for "optical automation and modbus" that ran a version of the Android Open Source Project. I looked over the site a bit with a google translate, but couldn't find many details about it.