HazardsMind:
Have you though about your SRAM? 72*72 = 5184, now you made them ints, so now thats 10368 of the 2K on an UNO or 4K on a Mega.
No, I haven't, and there isn't a problem. I would have thought any problem in this arena would have been immediately apparent when compiling, since I imagine the space would be demanded on declaration of the array. The array is 72x2, I can see the full 6 minute's worth read back to the monitor, and it works just fine. My only problem is drawing the graph using the numbers derived therefrom.
Why do you need to record everything?
I don't. Arduino could run for hours but it only loops once per second for the first six minutes and in that time the recording is only every fifth loop and only two numbers - hence 144.
Why not just draw the points as the data comes in? Of course you need two sets of coordinates, so that's where you have n_X/Ypoint(new) and o_X/Ypoint(old)
That is exactly what I do for the rest of it. The first graph is updated every second, The second graph is updated every five seconds after the first 6 mins (should be) redrawn from the array on the 5 second/pxl scale.. As it happens, the whole circus is continuously recorded on SD every ten seconds, and there is no problem with that either. Indeed, if the array did not work, one rather desperate option was to double the x increment and simply lift the values off the SD. I imagine it would be a lot slower, and it doesn't solve the problem anyway.
I'm sure you can work out the rest from there
Not really.............
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