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printing large numbers to LCD screen 
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Joined: Sun Jul 10, 2011 3:34 pm
Posts: 30
Post printing large numbers to LCD screen
Hello,
I am having a hard time printing large numbers to the VEX LCD screen with Cortex. I can only get 5 digit numbers to print. If I print a six digit number, the last number is cut off, or I get a value of 32767. I have used int, long, and float data types. I also tired to use double, but Robotc automatically converts it to a float. I cannot get it to print. Any help would be great. I placed the code below. Some of the variables come from earlier in the program. I am expecting t to be a 6 digit number.

float q = ((((nMotorEncoder[rightMotor]) + (abs(nMotorEncoder[leftMotor])))/2.0) + 250.0);
float adj = (q * 0.545666667);
long a = ((41.91*x)/177.0);
long theta = (sinDegrees(a)/cosDegrees(a));
long h = (adj*theta);

long tr = 0.5*h*adj;
long t = tr;

clearLCDLine(0);
clearLCDLine(1);
displayLCDPos(1,0);
displayNextLCDString("(mm^2)");
displayLCDPos(0,0);
displayNextLCDNumber(t,1);
wait1Msec(1000);


Fri Mar 08, 2013 2:38 pm
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Joined: Thu May 24, 2012 12:15 pm
Posts: 556
Post Re: printing large numbers to LCD screen
There are a couple of issues with this particular piece of code. The Long data type can only store whole integer numbers; if you attempt to store a decimal number in one, it will drop the decimal values and only store the integer value. This may result in either inaccurate or zero'd values. Another issue is that the 'displayNextLCDNumber' command can only display integer numbers, as per ROBOTC's intrinsic values:

Code:
intrinsic void displayNextLCDNumber(const int nValue, const int nPrecision = 0x40)


This is why you will see the overflow value (32767) of a integer, because you have essentially filled the memory space allocated to that variable.

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Mon Mar 11, 2013 5:43 pm
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