sprintf and number percision question?

[Trampas Stern]

Hi,

I was wondering how to do the following, or if their is a better way?

char conversion[15];
char data[15];
float num;

num=12.34;
sprintf(conversion,"\%\%5.2f");
sprintf(data,conversion,num); //data gets "12.34"?

I could not get the above code to work. Basically I trying to display a number with a user selectable percision. That is the user could say I want 2 decimal places or 3. I thought the above code would be a good way to do this. Does someone have a better soultion?

Thanks
Trampas
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This message was ported from CCS's old forum
Original Post ID: 11297

[Sherpa Doug]

:=Hi,
:=
:=I was wondering how to do the following, or if their is a better way?
:=
:=char conversion[15];
:=char data[15];
:=float num;
:=
:=num=12.34;
:=sprintf(conversion,"\%\%5.2f");
:=sprintf(data,conversion,num); //data gets "12.34"?
:=
:=I could not get the above code to work. Basically I trying to display a number with a user selectable percision. That is the user could say I want 2 decimal places or 3. I thought the above code would be a good way to do this. Does someone have a better soultion?
:=
:=Thanks
:=Trampas

I think the sprintf format is set at compile time. Either print a big format to a string and trim it from there, or select from multiple sprintf statements.

Its only an itty bitty PIC, you are asking a lot of it!

___________________________
This message was ported from CCS's old forum
Original Post ID: 11304

[Trampas Stern]

Why are people always saying the PIC is small? I am using a 18F8720 which has 10MIPS and tons of code space.

I guess I will implement a switch/case statement which would take more code space and execution cycles than the sprintf, good thing the pic is not small...

Trampas

:=:=Hi,
:=:=
:=:=I was wondering how to do the following, or if their is a better way?
:=:=
:=:=char conversion[15];
:=:=char data[15];
:=:=float num;
:=:=
:=:=num=12.34;
:=:=sprintf(conversion,"\%\%5.2f");
:=:=sprintf(data,conversion,num); //data gets "12.34"?
:=:=
:=:=I could not get the above code to work. Basically I trying to display a number with a user selectable percision. That is the user could say I want 2 decimal places or 3. I thought the above code would be a good way to do this. Does someone have a better soultion?
:=:=
:=:=Thanks
:=:=Trampas
:=
:=I think the sprintf format is set at compile time. Either print a big format to a string and trim it from there, or select from multiple sprintf statements.
:=
:=Its only an itty bitty PIC, you are asking a lot of it!
:=
___________________________
This message was ported from CCS's old forum
Original Post ID: 11329

[Sherpa Doug]

:=Why are people always saying the PIC is small? I am using a 18F8720 which has 10MIPS and tons of code space.
:=

I guess it is the way I use PICs. I still use the 16C5X series of chips. Most of my C code fits in 512 bytes. My tiny programs are easy to debug. Only when I have to do a lot of human interaction do I need the bigger 2K chips. If I have logical operations that take more code I usually use multiple PICs.

My first paying PIC job was for a project I inherited when the lead engineer was fired. He was trying to use a 386 at 120MHz to do eight range calculations in assembly in real time, and failing. I put a 16C54 at 20MHz on each range with one 16C58 to collect the results from the 16C54s and packetize it for export to a PC. I am now doing ten ranges fine. The bottleneck is the RS232 port to the PC, but the next generation will use Ethernet instead.

Moral of the story: A pack of itty bitty PICs can sometimes out do a mighty X86.

___________________________
This message was ported from CCS's old forum
Original Post ID: 11353

[Trampas Stern]

My personal love the fact the PICs have everything, memory, flash, IOs, ADC all on the chip. I also have 4 PICs on my current design some small ones as Analog to Digital and then the 18F8720 to collect and provide user interfacing.

Thus their is a PIC soultion for every problem....

Trampas
___________________________
This message was ported from CCS's old forum
Original Post ID: 11361