A way to remove lookup tables and calculate those values?

[aratti]

Since it is not clear to me what you want to acheive, I will attach a simple program in VB6 from which you can see how to use maths for drawing as many points you want on any given circle. All the maths are inside command1_click and should be not too difficult for you to translate the VB code into PBP code.

Cheers

Al.

[sccoupe]

I tried using sin/cos calculations and it resulted in the same speed or maybe slightly slower. I am only using 9600 baud out. This may be where im hanging up. I didnt figure that it would be the bottleneck in the operation. The next test will be to bump up the baud rate and see what happens.

EDIT: I changed over to the USART and set it up at 19200 and sure enough its displaying the gauge points twice as fast. Now, I have to tie the 2 USART transmit pins together because I have to initiate communication with the GPU at 9600 baud and then change the baud rate. I need to change the baud rate for one USART on the fly and re-DEFINE-ing the baud rate doesnt seem to work.

[cncmachineguy]

I think you will have to address the baud rate reg directly if you want to change on the fly. As near as I can tell, DEFINE will only work once in the program. Someone correct me if I am wrong

[Charles Linquis]

You can change the baud rate "on the fly". I generally try to find a combination of BRGH and BRG16 that will give me both of the baud rates that I want with writing only to SPBRG.

I normally run at 40Mhz, so with the following in the header

DEFINE HSER_RCSTA 90H
DEFINE HSER_TXSTA 24H
DEFINE HSER_CLROERR 1

Then, in the main program...


You can run at 9600 baud with the statement:

SPBRG = 255


Or at 57600 baud with the statement:

SPBRG = 42