////////////////////////////////////////////////////////////////////////////
//
// KNIHOVNA PRO PRACI S TOUCH MEMORY FY DALLAS
//
////////////////////////////////////////////////////////////////////////////
//
// PEFI S.ICZ a.s. 2002, 2003
//
// Verze 1.0
// 1.1 - pridana podpora vypinani pullupu
// pres pin TOUCH_PULLUP_PIN
// 1.2 - vyrazena podpora pullupu, do obecne knihovny nepatri
// - funkce checkCRC se stala soucasti fce read_sn
// - upraveny nazvy funkci, zpetna kompatibilita neni potreba
// 1.3 - pridana samostatna funkce pro kontrolu CRC
//
///////////////////////////////////////////////////////////////////////////
//
// funkce:
// int8 TM_present()
// - vraci TRUE, pokud je TM pritomna
//
// int8 TM_read_byte()
// - precte bajt z TM
//
// int8 TM_write_byte(int8 data)
// - zapise bajt do TM a vraci TRUE, pokud se to povedlo
//
// int8 TM_read_sn(int8 *sn)
// - precte seriove cislo z TM pomoci prikazu 0x33
// - vraci TRUE, pokud je SN platne (spravne CRC)
//
// definice a prepinace
// #define TM_PIN /* pin, na kterem je touch memory pripojena */
// #bit TM_PIN_BIT /* totez, ale definovan jako bit */
//
//
// defaultni definice
#ifndef TM_PIN
#define TM_PIN PIN_B0
#bit TM_PIN_BIT = PORTB.0
#endif
/****************************************************************************************************/
// Privatni sekce, cist jen v pripade, ze neco nefunguje
/****************************************************************************************************/
// precte bajt z touch memory
//
int8 TM_read_byte() {
int8 i,data;
for(i=0;i<8;++i) {
output_low(TM_PIN);
delay_us(14);
output_float(TM_PIN);
delay_us(5);
shift_right(&data,1,input(TM_PIN));
delay_us(100);
}
return(data);
}
// zapise bajt do touch memory
//
int8 TM_write_byte(int8 data) {
int8 i;
for(i=0;i<8;++i) {
output_low(TM_PIN);
delay_us(10);
if(shift_right(&data,1,0)) {
output_float(TM_PIN);
delay_us(1); // k vuli nabehu jednicky pres pullup
if(!TM_PIN_BIT) return(0);
} else {
output_low(TM_PIN);
if(TM_PIN_BIT) return(0); // k vuli nabehu nuly
}
delay_us(50);
output_float(TM_PIN);
// delay_us(50);
}
return(TRUE);
}
// testuje pritomnost touch memory, pri pritomnosti vraci TRUE
//
int8 TM_present() {
int1 present;
output_low(TM_PIN);
delay_us(500);
output_float(TM_PIN);
if(!input(TM_PIN))
return(FALSE);
delay_us(65);
present=!input(TM_PIN);
delay_us(240);
if(present)
return(TRUE);
else
return(FALSE);
}
// zkontroluje CRC zaznamu, vraci TRUE, pokud je zanam spravny
//
int8 TM_check_CRC(unsigned int8 *sn, unsigned int8 num)
{
#ifdef CRC_TAB
// tabulka pro vypocet CRC
const int8 TouchCRC[256]= {
0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205,
17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80,
175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238,
50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53};
#else
int8 j,k,l; // promenne potrebne pro algoritmicky vypocet CRC
#endif
int8 CRC; // prubezne CRC
int8 i;
#ifdef CRC_TAB
// vypocet CRC tabulkou
CRC=0;
for(i=0;i<num;i++) CRC=TouchCRC[CRC ^ *(sn+i)];
if(CRC!=*(sn+7)) return(0);
else return(1);
#else
// vypocet CRC algoritmicky
CRC=0;
for(i=0 ;i<num;i++) {
k=*(sn+i);
#asm
movlw 8
movwf j // citac bitu
loop:
movf k,W // presun bajt do W
xorwf CRC,W // prixoruj CRC a uloz do w
movwf l
rrf l,F // naxorovany bit do CY
movf CRC,W
btfsc 3.0 // preskoc, je-li CY nulove
xorlw 0x18
movwf CRC
rrf CRC,F // rotuj CRC
rrf k // na dalsi bit
decfsz j,F
goto loop
#endasm
}
if(CRC!=0) return(0);
else return(1);
#endif
}
// precte seriove cislo z touch memory, vraci TRUE je-li platne (spravne CRC)
//
int8 TM_read_sn(unsigned int8 *sn)
{
int8 i;
// precteni SN z touch memory
TM_write_byte(0x33);
for(i=0;i<8;i++) *(SN+i)=TM_read_byte(); // precti SN do buferu
if(*sn==0) return(0); // family kod je nulovy a to je chyba, timto nahrazujeme precteni samych nul, coz ma platne CRC, ale neexistuje
return(TM_check_CRC(SN,8));
}
// End of FIle
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