I don't know what PLL is, however the data stream coming in is at 115200 bits per second, and processor expert can be set to either baud (not sure if that is the same as bps) or ticks... which I believe has something to do with the clock.
There is an option in the same dialog box (bean settings) for overclocked. I left it alone...
I've tried cross connecting, to no avail. It could easily be that I was doing something else wrong at the same time though... suppose i'll try again. 
Part of the problem is that the baud rate being set by processor expert is not close enough to the target baud rate of 115200. When you enter a baud rate PE will attempt to adjust a divisor to get the baud rate you want, the closest it can get for you is 125000 which gives an error of ~8.5% which is too high.
Franklin wrote:I don't know what PLL is, however the data stream coming in is at 115200 bits per second, and processor expert can be set to either baud (not sure if that is the same as bps) or ticks... which I believe has something to do with the clock.There is an option in the same dialog box (bean settings) for overclocked. I left it alone...I've tried cross connecting, to no avail. It could easily be that I was doing something else wrong at the same time though... suppose i'll try again.
Jim mentioned the PLL(Phase Locked Loop), it gives you the ability to change the bus clock speed. The bus clock is used to generate the timing for your serial port, if you can change the bus clock to an appropriate value you should be able to get this error lower. I would suggest trying to get it to within +/-3%.
Under the CPU bean you have to Enable the PLL clock which will let you change the Internal bus clock. A reasonable bus clock speed that I would try first is 14.74MHz, it will set it to the closest possible bus clock speed.
I set it to 24 MHz, 0.16% error, but still no luck.
When I run the program, some other unused variables are randomly changing, but the one I am trying to use to hold the received characters does not change. Here is my code...
AS1_Enable();
for(;
{
{
r = AS1_GetCharsInRxBuf();
if(r>0)
{
AS1_OnRxCharExt(temp);
if(r>0)
{
AS1_OnRxCharExt(temp);
//AS1_RecvBlock(&temp, r, &reall);
AS1_RecvChar(&temp2);
//AS1_SendChar(temp);
}
AS1_RecvChar(&temp2);
//AS1_SendChar(temp);
}
}
Does the code inside the the if statement ever run? The call to AS1_OnRxCharExt won't do anything, unless you put some code in that function. That function is called in the ISR when a character is received and is empty until you change it, so temp would not be changing. temp2 should be changing, where have you declared these variables and how have you seen that they are not changing?
Franklin wrote:I set it to 24 MHz, 0.16% error, but still no luck.When I run the program, some other unused variables are randomly changing, but the one I am trying to use to hold the received characters does not change. Here is my code...AS1_Enable();for(;
{r = AS1_GetCharsInRxBuf();
if(r>0)
{
AS1_OnRxCharExt(temp);//AS1_RecvBlock(&temp, r, &reall);
AS1_RecvChar(&temp2);
//AS1_SendChar(temp);
}}
the stuff inside the if statement never ran. I checked using the debugger to step through.
However, since then i've switched prototyping boards, and now the "temp2" variable changes. However, I believe it's not properly interpretting the data coming in.
The input data (i believe) is in the form of a character stream. I can read it on hyper terminal, and the output is stuff like ' DB = 442, Beacon ID: 12341234'
Now, the variable temp does not change as rapidly as it should be (I think). I have the debugger sampling as fast as it will go... and temp only changes to a new value every second or so.
Also of interest -- I have tried sending characters out through the serial port to the pc, to hyperterminal. I'm sure the baud rates are matched but only junk is coming out. Stuff like, "xxxxxxxxxxxx" or some funky epsilon. So, my theory is that the values the "temp2" variable is holding, is similarly being misinterpreted. (temp will vary, for example, as follows: 2, 3, 6, 214, 240, 6)
I think my problem now, has something to do with having the microcontroller interpretting the data properly-- and putting it in the proper form if sending.
Also, something I don't understand-- if I used the function AS1_RecvBlock(TComData *block, word size, word *num) How can it store a whole block of data in what is essentially a character variable? (TComData is of type byte, i think? which is of type unsigned char? ) I am confused Any help greatly appreciated!
Any help greatly appreciated!
Franklin wrote:Also, something I don't understand-- if I used the function AS1_RecvBlock(TComData *block, word size, word *num) How can it store a whole block of data in what is essentially a character variable? (TComData is of type byte, i think? which is of type unsigned char? ) I am confused
It a unsigned character that you must pass, you pass a pointer to an unsigned character. In this case you would want to pass an array of unsigned characters that is large enough to hold the amount of data you are attempting to extract from the receive buffer. Like:
Code:
word RxBytes; // Number of bytes actually loaded into RxDatabyte RxData[10]; // Array to hold extracted databyte Status; // Store any errors returned ...Status = AS1_RecvBlock(RxData,10,&RxBytes); // Attempt to get 10 bytes from AS1
Thank you Brett, I am glad to hear that it IS sending in ASCII and there is no strange sub-protocol or anything causing my problem.
I tried setting the Oscillator frequency [MHz] to 4.0, but I am still not getting any coherent data. The Internal bus clock is set to 24.0 mHz... I am not sure what all of these settings do. It is likely something very simple, that I have just overlooked because I am so inexperienced. Your help is very appreciated! 
