First, let's clarify what "sending a message" means. It can be
- a property setting on the device
- load a file on the device
- call a device service
- remote desktop session
All of the mentioned cases are covered well by examples of the C SDK. If you could tell how you connect your device (EMS? REST? SDK?) and what you want to achieve it will be easier to show you how to do this.
I apologize for not being explicit. Here's the complete scenario:
We have a thing (raspberry pi) which is connected to the ThingWorx platform and is running one of the nodejs thing-agent files. It was very easy for me to get data. (in fact, it was already in the default nodejs file)
Now, I want to do something of this sort. In my mashup I want to have a button. 1.) Upon clicking, the button should ask the device to send it the required values ( which the raspberry gets from sensors and other devices connected to it) 2.) It should, upon clicking some other specific button, it performs another action which I will define in the nodejs script running on the device.