HazardsMind:
LOT of unneeded parentheses throughout your code. Things getting type casted from float to int only to end back in a float variable.
Yes, I'm feeling my way with this stuff, and the () are essentially a precautionary measure. I reposted the code with a swag of them removed, although the sensor reading stuff has been there for a couple of years. One thing I have learned from this is that I thought I was using the Hacktronics DS18B20 stuff essentially verbatim all along. Not true. I now believe it got bent after discussion with Stanley Seow in KL.
What I want is to convert the float to a pixel count - one pixel = 0.1 degrees for the graph 120 pixels high. I realise things are probably scruffy there but it works and is not the real problem
Your function "readArray()" has Serial.println(rises*); in it, so what does it output? Do you ever see them display in the serial monitor?*
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Yes, as I said in OP, the subroutine regurgitates to monitor OK, I just can't draw the lines. I don't need the array on screen, but I see what I expect to see - 19 floats.
> What does kWs output? Do you see any kind of line at all?[/quote]
> No. As I said in the OP, the array is OK but I cannot draw the lines. What I did not properly explain is that I have three, actually four types of graph displayed sequentially.
> 1. the first 6 minutes at 1pxl/second.
> 2. the same 6 minutes derived from the array, displayed at 1pxl/5 seconds, followed by
> 3. the next 24 minutes at 1pxl/5 seconds to give a total of 360pxl = 30 minutes.
> 4. all subsequent graphs 30 minutes at 1pxl/5 seconds
> The only problem is that I can't draw the lines in case 2.
> I'm sure you understand the intent - the main action is at the start of the event and merits the expanded scale, while the combined graph of thirty minutes gives the overall picture. The subsequent displays are largely ceremonial and probably better handled by Android anyway.
> Note that I have only recently got this 400x240 TFT to work OK. It IS OK but I am obliged to use a code for a 480x320, which means that all this is just the sort of thing that can go wrong. It might also explain why some of the code might not look like one would expect.