I'm trying to graph some data that's gathered from an Arduino board,
but I keep having trouble with screen flicker while graphing. This only seems to happen when I'm trying to draw other shapes or text to the canvas while graphing. I have tried drawing the data to a Pgraphics object and then displaying the Pgraphic object on the canvas, but I'm not sure I'm doing these things in the correct order.

The pseudocode for my first try was:

void setup()
{
do typical setup stuff and make a Pgraphics object
}

void draw()
{
Draw static shapes and text
}

void serialEvent(Serial ComPort)
{
-read serial data from arduino
-add data to an array
-graph array data on Pgraphics object
-display Pgraphics object in specific place on canvas
}


This made the graph flicker, but the static objects did not flicker.
The next try made the whole canvas flicker like mad:

void setup()
{
do typical setup stuff and make a Pgraphics object
}

void draw()
{
-set background color
}

void serialEvent(Serial ComPort)
{
-read serial data from arduino
-add data to an array
-graph array data on Pgraphics object
-draw static graphics and text (not in Pgraphics object)
-display Pgraphics object in specific place on canvas
}


I'm about to try a few more combinations of canvas drawing and Pgraphics drawing, but I'm hoping someone can shed some light on the root cause of the flickering overall.
Some specific questions I have are:
- Should I be using serialEvent(Serial ComPort) to handle the
data capture, or is there a better way?
- When using a PGraphics object, does using P2D vs. P3D make a difference?
- Note, I have tried writing -all- the graphics to a PGraphics object, but it seems impossible to write text to a PGraphics object - I have tried everything I can think of to write text to a PGrpahic, but I get error after error. Anyone else out there have any experience trying to do this?
- Also note, the PGraphics object that I'm writing to and displaying is much smaller than the main canvas, so I don't think the flicker is caused by overlapping of the static graphics and the graph.

Thanks Cedric, problem solved! <facepalm>...seems so obvious now...