I am using a control unit that consists of an arduino, Ethernet shield, Xbee shield and Xbee, and I am trying to control a led as a dimmer using an android.
I used the MIT App Inventor to implement the app using a slider. The problem that I can't find the block to be inserted to be able to send the (thumb position) of the slider to the control unit.
I tried to use the (PostText) block but it didn't work. I keep receiving (-1) value each time I try to serial read the output, which I guess means that the output is empty.