Signed to unsigned conversion

[Poul_Thomsen]

Hi,

I am receiving a 16 bit unsigned value for I2C bus.
As the dispaly treats this as a signed value, I have written this conversion code to be able to display the value on the screen.

But is there a smarter (faster) solution?


// Convert channel 0 to unsigned and print
// ADC_0 is a 2 byte unsigned value from I2C Bus.

var TestNegativeSign:=0b1000000000000000;

var Tmp; // temporary signed 16 bit var

var DTmp[2]; // temporary Float var

var FADC_0[2]; // Resulting Float var


1 if (ADC_0&TestNegativeSign) // Test if MSB(7) is set, which will result in an unwanted negative number

2 Tmp:=ADC_0&0b0111111111111111; // Change MSB(7) to 0

3 flt_ITOF(DTmp,Tmp); // Load the Tmp value into DTmp Float var

4 flt_VAL(FADC_0,"32768"); // Load Result with the MSB(7) that was removed in line 1

5 flt_ADD(FADC_0,FADC_0,DTmp); // Add the remaining bits

6 else // MSB(7) was not set

7 flt_ITOF(FADC_0,ADC_0); // Use the original value.

8 endif

9 flt_PRINT(FADC_0,"%.0f");


Thanks in advance

Poul

[ivan_4d]

Hi Poul,

You can try this code below to display a 16-bit unsigned value.

var value := 0xFFFF; // this the value from I2C, let's try it with 65535
var ptr; //declare pointer to the value
ptr := str_Ptr(&value); // let's create a pointer for printing the unsigned long value
str_Printf(&ptr, "%u"); // print the value as unsigned int

I hope this helps.

If you have other inquiries, feel free to open a ticket here 4D Systems helpdesk or a new forum post.

Best regards

[Poul_Thomsen]

Hi ivan_4d

Thanks, exactly want I wanted!

regards Poul

[ivan_4d]

Hi Poul,

We're happy to help.

If you have other inquiries, feel free to open a ticket here 4D Systems helpdesk or a new forum post.

Have a great day!

Best regards