Thanks for taking time!
Ok, in short : I got a microcontroller (so I can expect strange stuff with
ram, minimal functions etc.) attached with RS232 to HyperTerminal. In It's
EEPROM all kind of stuff is stored. With several commands in HP I can read
or write. That part works
for now but one function for the adressing not. Of course, before start
reading anything I'll have to give a start position.
The function I showed in the previous post is for calculating the start
position for Port data. With port I mean some in- outputs that are attached
to the microcontroller. With one command I can call all the data of such a
port. A port has more than 1 properties (ala object orientated programming)
so the end result has to be a long string with all the data like this
<name>|<ID>|<unit>|<enabled>|<and so on
You can forget about that part, the error lies in the "Port_getPortNum"
function which returns the index of the asked port object. That has to be a
number from 1..14. By looking at the given name it can be calculated.
Everything works... But, only when that fprintf is included. If I remove it
for some reason it won't work. Here's some code. I didn't have the time to
setup a
working program but this might clear up the situation.
const unsigned long PORT_OFFSET = 1024*8;// EEPROM offset
const unsigned long PORT_TYPE_SIZE = 338; // Size of 1 port 'object'
char gv_SR[15]; // Serial command buffer
// This should return the port number, port is given as a string,
// @AI<number> for analog input 1..6
// @DI<number> for analog input 1..4
// @AO<number> for analog output 1..2
// @DO<number> for analog output 1..2
// In total we got 14 ports, numbered 1..14
// If I remove the first fprintf the whole IF stuff get's skipped, meaning
no
// A or D was detected on port[1].
unsigned int8 Port_getPortNum( char *port )
{
fprintf(DB9, "port = %s\r\n", port ); // MAGICAL PRINTF
if ( port[1] == 'A' )
{
if ( port[2] == 'I' ) return port[3]-48; else
if ( port[2] == 'O' ) return port[3]-38;
}else
if ( port[1] == 'D' )
{
if ( port[2] == 'I' ) return port[3]-42; else
if ( port[2] == 'O' ) return port[3]-36;
}
fprintf(DB9, "ERROR [3] = %c\r\n", port[3] );
return 0; // If it reaches this point something is wrong
} // Port_getPortName
// Read data out of EEPROM and put it into one large string.
// But before we're going to read I need to know where to start
// reading. And that's we're the error occurs
// The port parameter is the port name, result is an output buffer
void PORT_EXPORT( char port[5], char *result )
{
unsigned long pos;
unsigned int8 x; // For testing
x = Port_getPortNum(port);
fprintf( DB9, "PORTID = %U\r\n",x ); // print to RS232 stream
pos = PORT_OFFSET + ( (x-1) * PORT_TYPE_SIZE );
< the export functions, read stuff at 'pos'
we just calculated >
}
void someTestFunction()
{
// GV_SR is used to store a serial command, types in
// by hyperterminal. When I hit enter this void gets
// started. Maybe... the port parameter in PORT_EXPORT is a 5
// long string, GV_SR is 15 long. If I type '@AI1' (+ an enter) it will
// take 5. Maybe I'll have to size the parameter up to 15 as well?
char result[200] = "";
PORT_EXPORT( GV_SR, result );
< clear GV_SR for next command >
< print the result >
}
Greetings,
Rick
