Yes you are right. I meant receive buffer. When I compiled the sketch, following msg was displayed :
Sketch uses 129140 bytes (50%) of program storage space. Maximum is 253952 bytes.
Global variables use 7390 bytes (90%) of dynamic memory, leaving 802 bytes for local variables. Maximum is 8192 bytes.
Low memory available, stability problems may occur.
That means I am low on RAM
If that is the case then how can I increase RAM
Should I use another Board that has faster processor and more RAM such as RADDS?
Eventually I have a plan to use 5extruders with a mixing color.
Thanks