LCD displays wrong temperature

Question

Hi I have a program that does not work right as I aspect:

v = tempC;
h = tempC * 10;
h = h % 10;
memset(stempCA, 0, sizeof(stempCA));
sprintf(stempCA, "%+.2d.%d", v, h);

it works fine on positive temperature "+11.22" but not for negative values : "-02.-1"

where is my mistake? thanx

> where is my mistake? test the temperature first to see if it is negative or positive. your code works for positive temperatures only. — dannyf, Commented Jan 22, 2017 at 16:23

gilhad · Accepted Answer · 2017-01-22 15:54:38Z

1

I think, that -1%10=-1, not 9 as you would like. I use

if (tempC<0) {print'-';tempC=-tempC;};
print tempC as usual for positive numbers

answered Jan 22, 2017 at 15:54

gilhad

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no , I put it in a Buffer for LCD display, I don't use print : sprintf(Buffer2, "U:%s A:%s", stempCU, stempCA);
– Jens-Uwe Klehm
Commented Jan 22, 2017 at 16:16
Got i myself: sprintf(stempCA, "%+.2d.%d", v, abs(h));
– Jens-Uwe Klehm
Commented Jan 22, 2017 at 16:49

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