Hi this is one of my first sketch, it's not finished, just wanted to know if i m on the right track, and some advice on how i continue it,
It's a sketch which read the input of a serial Tablet ( like a wacom thing ), define statuts ( pen hovering, pen pressing, or no pen ) and then the coordinate, the protocol is in 5 bytes.
/* Topaz Tablet drawing app
This a program that reads the five bytes protocol from a Serial Topaz Tablet and then
converting them in three variables : Statut, x,y and draw the result if the statuts is set to "draw" and print value of the statut,x, and y.
*/
// Define constant
#define TOPAZ_PACKET 5
// Declares variables
int buffer[5];
int topaztablet = 0;
int statut = 0;
int x = 0;
int y = 0;
int packetlen = 0;
int packet = 0;
void draw(int x, int y) // prototype, not yet used in the sketch.
// Will be called when a good data packet is recognized with the statut draw and then draw.
{
// code
}
void setup() // Setup of the tablet and the arduino input
{
Serial.begin (19200);
}
void loop () // Read incoming bytes.
{
Serial.available();
packet = Serial.read();
if (packetlen > 0);
{
packetlen = 0;
}
if (packetlen < TOPAZ_PACKET);
{
packetlen++;
}
if (packetlen == TOPAZ_PACKET);
{
packetlen = buffer[5];
}
}
/* Topaz Tablet drawing app
This a program that reads the five bytes protocol from a Serial Topaz Tablet and then
converting them in three variables : Statut, x,y and draw the result if the statuts is set to "draw" and print value of the statut,x, and y.
*/
// CONSTANTS
//
#define TOPAZ_PACKET 5
// VARIABLES
//
int buffer[5];
int buflen =0; // how far is buffer filled
/////////////////////////////////////////
//
// CODE STARTS HERE
//
void setup()
{
Serial.begin (19200);
}
void loop ()
{
// COLLECT PACKET
while ( Serial.available() > 0 && buflen < TOPAZ_PACKET )
{
buffer[buflen ] = Serial.read();
buflen++;
}
// PROCESS PACKET
if ( buflen == TOPAZ_PACKET ) // do we have a full buffer?
{
// reset buflen so next packet can be collected
buflen = 0;
// parse the content of buffer and do you thing
...
}
}
Ok, i think i have reached my limits, i ll study more because, i feel stuck.
I was reading from the tablet developper reference that the draw ( first byte from the 5 bytes packet when pen is down ) expected value is "241" (240 when pen is near but not down, and 176 for no pen near at all ), but when i monitor using hyperterminal, the hex i see for draw is 87, i ve converted it to everything and nothing match the mysterious "241"...
i ve tried to continue the code, but obviously i'm doing stuff the wrong way.
any help is welcome.
Regards
/* Topaz Tablet drawing app
This a program that reads the five bytes protocol from a Serial Topaz Tablet and then
converting them in three variables : Statut, x,y and draw the result if the statuts is set to "draw" and print value of the statut,x, and y.
*/
// CONSTANTS
//
#define TOPAZ_PACKET 5
// VARIABLES
int buffer[5];
int buflen =0; // how far is buffer filled
int statuts = 0;
int subcol = 0;
int numcol = 0;
int subline = 0;
int numline = 0;
int x = 0;
int y = 0;
/////////////////////////////////////////
//
// CODE STARTS HERE
//
void setup()
{
Serial.begin (19200);
}
void loop ()
{
// COLLECT PACKET
while ( Serial.available() > 0 && buflen < TOPAZ_PACKET )
{
buffer[buflen ] = Serial.read();
buflen++;
}
// PROCESS PACKET
if ( buflen == TOPAZ_PACKET ) // do we have a full buffer?
{
// reset buflen so next packet can be collected
buflen = 0;
statuts = buffer[0];
subcol = buffer [1];
numcol = buffer [2];
subline = buffer [3];
numline = buffer [4];
}
if ( buffer[0] == 176, 240, 241 )
{
x = 0;
y = 0;
x = ((((numcol*128)+subcol)/4)-37);
}
if ( x > 128 )
{
x = 128;
}
y = ((((numline*128)+subline)/5)-10);
drawing (statuts, x, y);
}
int drawing (statuts, x, y)
{
// code about drawing
}
}
}
