Currently there are no plans to update the tunnel to work with EV3 (as I am working on the EV3 firmware). Monobrick communication library already has support for Wifi/Network without the tunnel.
Doing a PID over a WiFi connection or Bluetooth connection is not a good idea. A PID needs to real time. Use the MonoBrick firmware instead and execute the programs directly on the brick. The firmware has support for setting both the speed and power directly. It even has its own PID implementation. Have a look here.
I don’t think that you have a proper connection to the brick. You are using a network connection – you write that it happens sometimes – but is there some kind of a pattern?
Don’t you want to upload the file instead of downloading it? Anyway make sure the file that you want to copy/send/upload to the brick is place in the same folder as the program that is executing.
You are mixing code from the communication library and the Monobrick firmware… please create a simple console application – if in fact you are trying to use the firmware.
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