18B20 temperature measurement C51 source program

#include # include #define BUSY1 (DQ1 == 0) sbit DQ1 = P0 ^ 4; unsigned char idata TMP; unsigned char idata TMP_d; unsigned char f; void wr_ds18_1 (char dat); unsigned char rd_ds18_1 (); / *************** delay procedure, US units, greater than 10us ************* / void TIme_delay (unsigned char TIme) {TIme = TIme -10; time = time / 6; while (time = 0!) time--;} / ************************************************* **** // * reset ds18b20 * // ************************************** *************** / void ds_reset_1 (void) {unsigned char idata count = 0; DQ1 = 0; time_delay (240); time_delay (240); DQ1 = 1; return;} void check_pre_1 (void) {while (DQ1); while (~ DQ1); time_delay (30);} void read_ROM (void) {int n; ds_reset_1 (); check_pre_1 (); wr_ds18_1 (0x33); for (n = 0; n<8; n ++) {ROM [n] = rd_ds18_1 ();}} / ************************************************* **** // * read a bit from 1820 bit read * // ******************************** ********************* / bit tmrbit_1 (void) {idata char i = 0; bit dat; DQ1 = 0; _nop_(); DQ1 = 1; _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_(); _nop_() ; _nop_(); dat = DQ1; time_delay (50); return dat;} / ************************************************* **** // * read a bety from ds18b20 * // byte read ******************************* ********************** / unsigned char rd_ds18_1 () {unsigned char idata i, j, dat = 0; for (i = 1; i< = 8; i ++) {j = tmrbit_1 (); dat = (j<.1881 (i-1.)) | dat;} return dat;} / ************************************************* **** // * write a bety from ds18b20 write byte * // ******************************** ******************** / void wr_ds18_1 (char dat) {signed char idata i = 0; unsigned char idata j; bit testb; for (j = 1;. j.1881 = 8; j ++) {testb = dat & 0x01; dat = dat>>1; if (testb) {DQ1 = 0; _nop_(); _nop_(); DQ1 = 1; time_delay (60);} else {DQ1 = 0; time_delay (50); DQ1 = 1; _nop_(); _nop_();}}} int get_temp_1 (void) {unsigned char idata a = 0, b = 0; unsigned char idata i; EA = 0; ds_reset_1 (); check_pre_1 (); wr_ds18_1 (0xcc); wr_ds18_1 (0x44); while (BUSY1); ds_reset_1 (); check_pre_1 (); wr_ds18_1 (0xcc); wr_ds18_1 (0xbe); a = rd_ds18_1 (); b = rd_ds18_1 (); i = b; / * If the temperature is negative and b is 1 * / i = (i. 1882.>4); if (i == 0) {f = 0; TMP = ((a>>4) | (b<<4)); a = (a & 0x0f); if (a. 1882.8) {TMP = (TMP + 1);}} else {f = 1; a = a>>4; b = b<<4; TMP = (a | b); TMP = ~ TMP; TMP = (TMP + 1);} EA = 1; return (TMP);} int get_temp_d (void) {unsigned char idata a = 0, b = 0; unsigned char idata i, m; EA = 0; ds_reset_1 (); // reset check_pre_1 (); wr_ds18_1 (0xcc); wr_ds18_1 (0x44); while (BUSY1); ds_reset_1 (); check_pre_1 (); wr_ds18_1 (0xcc); wr_ds18_1 (0xbe); a = rd_ds18_1 (); b = rd_ds18_1 (); i = b; / * If the temperature is negative and b is 1 * / i = (i>>4); if (i == 0) {f = 0; TMP = ((a>>4) | (b<<4)); a = (a & 0x0f) ; TMP_d = a;} else {f = 1; a = ~ a; a = (a + 1); b = ~ b; b = (b + 1); m = a; a = a>>4 ; b = b<<4; TMP = (a | b); m = (m & 0x0f); TMP_d = m;} EA = 1; return (TMP);}, read, technology zone About μClinux transplantation on ARM7 S3C4510B Multi-looped into charge and discharge controller design Interrupt service routines for ARM embedded systems LED dimming engine design based on 8-bit MCU How to display Chinese characters, ASCII characters and color graphics on the LCD monitor