Real time moving chart on TFT displays

[timtianyang]

Hi,

I want to plot a real time chart on a TFT in my embedded project. When there is more data coming in, the chart will shift to the left accordingly. I am not sure what the chart is called, maybe real time dynamic shifting chart? I searched it online but all I have is libraries already made for PC platforms. What I want is some low level implementation since it's on an embedded device.

I am programming using a standard ANSI C complier (mikroC), so all C syntax apply. However I can only use low level functions only. Function I have now:

void setColor(int color)//sets color for the plot. It can be used to erase plotted graph if the color is set to background color.
void Dot(int x,int y)//plots a dot on the TFT at (x,y), x and y is actual pixel on the screen.
void Line(int x1,int y1,int x2,int y2)//connects (x1,y1) with (x2,y2)

What I have in mind now is to store all x and y values to arrays and erase the whole chart when a new point is coming. After adding a new point to arrays, I will replot the chart with new arrays. However I can only make arrays with fixed length.

After some trials I abandoned shifting graphs. What I have now is that it will plot the whole screen, and erase it and then plot again starting from far left. It doesn't look as nice but it works. I am still very curious about how to shift graphs using those three functions.

Thanks in advance.
Tim

 

[timtianyang]

anyone? Really need some advice on that.