Arduino Driver Latency Setting

Official Hardware Mega Due
1

Hi,

I am using an Arduino Due and communicate with it to an PC running Windows.
I have found that there is a minimum latency of about 4 ms between sending an Question (one Byte) from PC to the Arduino and receiving an answer (1 Byte).
After some research I found that for using the FTDI driver there is a setting for the minimum latency (minimum 1 ms (due to usb latency)) UNO serial latency - Uno Punto Zero - Arduino Forum. But Arduino Due uses an own driver for communication (on both ports) which doesn't have this possibility (or i didn't found it).
My Questions are:

  • Is there a possibility to set it (which I haven't found)
    • If not:
      • Is there a possibility to implement/modify the driver or use another compatible driver for it which supports this setting?
        Thanks.

Greetings
Stefan

Sources:

http://forum.arduino.cc/index.php?topic=96.0

http://www.chipkin.com/reducing-latency-on-com-ports/

2

Which of the ports on the Due are you using? The programming port is completely worthless in my opinion. It's slow and redundant. I've never had a problem just using the native port for everything. Sure, sometimes you mess up a sketch so bad it locks up and you have to push the erase button. Big deal, there is an erase button right there for a reason. So, use the native port.

I believe you can tweak the comm parameters for the native port from within the CDC.cpp file that is found (in linux) at

.arduino15/packages/arduino/hardware/sam/1.6.4/cores/arduino/USB

That's relative to your user directory. In windows I believe that directory structure is somewhere around c:\users<yourusername>\Documents\Arduino15 or something like that. I forget exactly. But, the file is CDC.cpp

3

Hi

Thanks.
I forgot to mention that these measurements have been made using the programming port.
My workaround already was using the native port where the latencies are way smaller (minimum 1 ms).
I was just questioning myself if there is also a solution for this port (for example if your board doesn't have this possibility (like the Arduino Mega) and uses the all in one driver).

Just for your information in windows it is:
"Arduino\hardware\arduino\sam\cores\arduino\USB"
Inside the program folder

What do you mean by tweaking the comm parameters with the CDC.cpp?
As far as I have understood the 1ms latency I can measure is the USB Latency itself and so nothing I can change.

Greetings
Stefan