frederic blanc
onewire 1-wire ds18x20 ds2450 multi-channel
Diff: onewire.cpp
- Revision:
- 0:8c4e1841eb30
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/onewire.cpp Fri Mar 02 08:29:49 2012 +0000
@@ -0,0 +1,549 @@
+/**
+* @file onewire.c
+* @brief library 1-Wire(www.maxim-ic.com)
+* @author Maciej Rajtar (Published 10 May 2010 www.mbed.org)
+* @author Frederic BLANC (Published 01/03/2012 www.mbed.org)
+*/
+
+#include "mbed.h"
+#include "onewire.h"
+
+DigitalInOut ow_pin(p21);
+DigitalInOut ow_0(p21);
+DigitalInOut ow_1(p22);
+DigitalInOut ow_2(p23);
+DigitalInOut ow_3(p24);
+DigitalInOut* t_ow[4]={&ow_0,&ow_1,&ow_2,&ow_3};
+//**********************************************************************************************************
+//* show_id
+//**********************************************************************************************************
+
+
+/**
+* @brief show_id
+* @param [in] id[] = rom_code
+* @return [out] text id
+* @date 20/06/2011
+*/
+string ow_show_id( uint8_t id[]) {
+
+ char hex[4];
+ string text ("");
+ sprintf(hex,"%2.2X",id[0]);
+ text+=hex;
+ for (int i = OW_ROMCODE_SIZE-2; i >=1 ; --i ) {
+ sprintf(hex,"%2.2X",id[i]);
+ text+=hex;
+ }
+ sprintf(hex,"%2.2X",id[OW_ROMCODE_SIZE-1]);
+ text+=hex;
+ return text;
+}
+
+//**********************************************************************************************************
+//* search_sensors
+//**********************************************************************************************************
+
+/**
+* @brief search_sensors
+* @param [out] nSensors number of device onewire
+* @param [out] gSensorIDs[][] array of id romcode
+* @return OW_OK or OW_PRESENCE_ERR or OW_DATA_ERR
+* @date 20/06/2011
+*/
+uint8_t search_sensors(uint8_t *nSensors,uint8_t gSensorIDs[][OW_ROMCODE_SIZE] ) {
+
+
+ uint8_t i;
+ uint8_t id[OW_ROMCODE_SIZE];
+ uint8_t diff;
+ printf( "Scanning Bus\n" );
+ diff = OW_SEARCH_FIRST;
+ for (*nSensors = 0 ; (diff != OW_LAST_DEVICE) && (*nSensors < MAXSENSORS) ;++(*nSensors) ) {
+ ow_find_sensor( &diff, &id[0] );
+ if ( diff == OW_PRESENCE_ERR ) {
+ printf( "No Sensor found\r\n" );
+ return diff;
+ }
+ if ( diff == OW_DATA_ERR ) {
+ printf( "Bus Error\r\n" );
+ return diff;
+ }
+ for (i=0;i<OW_ROMCODE_SIZE;i++)
+ gSensorIDs[*nSensors][i]=id[i];
+
+ }
+ return OW_OK;
+}
+/**
+* @brief search_sensors
+* @param [in] n num bus onewire
+* @param [out] nSensors number of device onewire
+* @param [out] gSensorIDs[][][] array of id romcode
+* @return OW_OK or OW_PRESENCE_ERR or OW_DATA_ERR
+* @date 02/09/2011
+*/
+uint8_t search_sensors(uint8_t n,uint8_t *nSensors,uint8_t gSensorIDs[][MAXSENSORS][OW_ROMCODE_SIZE] ) {
+
+
+ uint8_t i;
+ uint8_t id[OW_ROMCODE_SIZE];
+ uint8_t diff;
+ printf( "Scanning Bus %d\r\n",n );
+ diff = OW_SEARCH_FIRST;
+ for (*nSensors = 0 ; (diff != OW_LAST_DEVICE) && (*nSensors < MAXSENSORS) ;++(*nSensors) ) {
+ ow_find_sensor(n, &diff, &id[0] );
+ if ( diff == OW_PRESENCE_ERR ) {
+ printf( "No Sensor found\r\n" );
+ return diff;
+ }
+ if ( diff == OW_DATA_ERR ) {
+ printf( "Bus Error\r\n" );
+ return diff;
+ }
+ for (i=0;i<OW_ROMCODE_SIZE;i++)
+ gSensorIDs[n][*nSensors][i]=id[i];
+
+ }
+ return OW_OK;
+}
+//**********************************************************************************************************
+//* find Sensors on 1-Wire-Bus
+//**********************************************************************************************************
+
+/**
+* @brief find Sensors on 1-Wire-Bus
+* @param [in/out] diff is the result of the last rom-search
+* @param [out] is the rom-code of the sensor found
+* @return OW_OK or OW_ERROR
+* @date 20/06/2011
+*/
+uint8_t ow_find_sensor(uint8_t *diff, uint8_t id[]) {
+ for (;;)
+ {
+ *diff = ow_rom_search( *diff, &id[0] );
+ if ( *diff==OW_PRESENCE_ERR)
+ return OW_ERROR;
+ if ( *diff==OW_DATA_ERR )
+ return OW_ERROR;
+ if ( *diff == OW_LAST_DEVICE )
+ return OW_OK ;
+ if ( id[0] == DS18B20_ID || id[0] == DS18S20_ID )
+ return OW_OK ;
+ if ( id[0] == DS2450_ID )
+ return OW_OK ;
+ }
+}
+
+/**
+* @brief find Sensors on 1-Wire-Bus
+* @param [in] num bus onewire
+* @param [in/out] diff is the result of the last rom-search
+* @param [out] is the rom-code of the sensor found
+* @return OW_OK or OW_ERROR
+* @date 30/08/2011
+*/
+uint8_t ow_find_sensor(uint8_t n,uint8_t *diff, uint8_t id[]) {
+ for (;;)
+ {
+ *diff = ow_rom_search(n, *diff, &id[0] );
+ if ( *diff==OW_PRESENCE_ERR)
+ return OW_ERROR;
+ if ( *diff==OW_DATA_ERR )
+ return OW_ERROR;
+ if ( *diff == OW_LAST_DEVICE )
+ return OW_OK ;
+ if ( id[0] == DS18B20_ID || id[0] == DS18S20_ID )
+ return OW_OK ;
+ if ( id[0] == DS2450_ID )
+ return OW_OK ;
+ }
+}
+//**********************************************************************************************************
+//* search romcode
+//**********************************************************************************************************
+
+/**
+* @brief search romcode
+* @param [in] uint8_t diff
+* @param [out] id romcode
+* @return next_diff or OW_LAST_DEVICE or OW_DATA_ERR or OW_PRESENCE_ERR
+* @date 20/06/2011
+*/
+uint8_t ow_rom_search( uint8_t diff, uint8_t id[] ) {
+ uint8_t i, j, next_diff;
+ uint8_t b;
+
+ if ( ow_reset() )
+ return OW_PRESENCE_ERR; // error, no device found
+ ow_byte_wr( OW_SEARCH_ROM ); // ROM search command
+ next_diff = OW_LAST_DEVICE; // unchanged on last device
+ i = OW_ROMCODE_SIZE * 8; // 8 bytes
+ do {
+ j = 8; // 8 bits
+ do {
+ b = ow_bit_io( 1 ); // read bit
+ if ( ow_bit_io( 1 ) ) { // read complement bit
+ if ( b ) // 11
+ return OW_DATA_ERR; // data error
+ } else {
+ if ( !b ) { // 00 = 2 devices
+ if ( diff > i || ((*id & 1) && diff != i) ) {
+ b = 1; // now 1
+ next_diff = i; // next pass 0
+ }
+ }
+ }
+ ow_bit_io( b ); // write bit
+ *id >>= 1;
+ if ( b )
+ *id |= 0x80; // store bit
+ --i;
+ } while ( --j );
+ id++; // next byte
+ } while ( i );
+ return next_diff; // to continue search
+}
+/**
+* @brief search romcode
+* @param [in]n num bus onewire
+* @param [in] uint8_t diff
+* @param [out] id romcode
+* @return next_diff or OW_LAST_DEVICE or OW_DATA_ERR or OW_PRESENCE_ERR
+* @date 30/08/2011
+*/
+uint8_t ow_rom_search(uint8_t n, uint8_t diff, uint8_t id[] ) {
+ uint8_t i, j, next_diff;
+ uint8_t b;
+ if ( ow_reset(n) )
+ return OW_PRESENCE_ERR; // error, no device found
+ ow_byte_wr(n, OW_SEARCH_ROM ); // ROM search command
+ next_diff = OW_LAST_DEVICE; // unchanged on last device
+ i = OW_ROMCODE_SIZE * 8; // 8 bytes
+ do {
+ j = 8; // 8 bits
+ do {
+ b = ow_bit_io(n, 1 ); // read bit
+ if ( ow_bit_io(n, 1 ) ) { // read complement bit
+ if ( b ) // 11
+ {
+
+ return OW_DATA_ERR; // data error
+ }
+ } else {
+ if ( !b ) { // 00 = 2 devices
+ if ( diff > i || ((*id & 1) && diff != i) ) {
+ b = 1; // now 1
+ next_diff = i; // next pass 0
+ }
+ }
+ }
+ ow_bit_io(n, b ); // write bit
+
+ *id >>= 1;
+ if ( b )
+ *id |= 0x80; // store bit
+ --i;
+ } while ( --j );
+ id++; // next byte
+
+ } while ( i );
+
+
+ return next_diff; // to continue search
+}
+
+
+//**********************************************************************************************************
+//* test pin onewire bus
+//**********************************************************************************************************
+/**
+* @brief test pin onewire bus
+* @return etat pin ow
+* @date 20/06/2011
+*/
+uint8_t ow_test_pin (void){
+ if (ow_pin)
+ return 1;
+return 0;
+}
+
+/**
+* @brief test pin onewire bus
+* @param [in] num bus one wire
+* @return etat pin ow
+* @date 30/08/2011
+*/
+uint8_t ow_test_pin (uint8_t n){
+
+ if (*t_ow[n])
+ return 1;
+return 0;
+}
+
+//**********************************************************************************************************
+//* onewire reset bus
+//**********************************************************************************************************
+/**
+* @brief onewire reset bus
+* @return pin ow or OW_SHORT_CIRCUIT
+* @date 20/06/2011
+*/
+uint8_t ow_reset(void) { // reset. Should improve to act as a presence pulse
+ uint8_t err;
+
+ ow_pin.output();
+ ow_pin = 0; // bring low for 500 us
+ wait_us(500);
+ ow_pin.input();
+ wait_us(60);
+ err = ow_pin;
+ wait_us(240);
+ if ( ow_pin == 0 ) { // short circuit
+ err = OW_SHORT_CIRCUIT;
+ }
+ return err;
+}
+
+/**
+* @brief onewire reset bus
+* @param [in] num bus onewire
+* @return pin ow or OW_SHORT_CIRCUIT
+* @date 30/08/2011
+*/
+uint8_t ow_reset(uint8_t n) { // reset. Should improve to act as a presence pulse
+ uint8_t err;
+
+ t_ow[n]->output();
+ *t_ow[n] = 0; // bring low for 500 us
+ wait_us(500);
+ t_ow[n]->input();
+ wait_us(60);
+ err = *t_ow[n];
+ wait_us(240);
+ if ( *t_ow[n] == 0 ) { // short circuit
+ err = OW_SHORT_CIRCUIT;
+
+ }
+ return err;
+}
+//**********************************************************************************************************
+//* read write onewire
+//**********************************************************************************************************
+/**
+* @brief read write onewire
+* @param [in/out] b data
+* @return data
+* @date 20/06/2011
+*/
+uint8_t ow_bit_io( uint8_t b ) {
+
+ ow_pin.output(); // drive bus low
+ ow_pin = 0;
+ wait_us(1); // Recovery-Time wuffwuff was 1
+
+ if ( b )
+ ow_pin.input(); // if bit is 1 set bus high (by ext. pull-up)
+ // delay was 15uS-1 see comment above
+ wait_us(15-1);
+ if ( ow_pin == 0 ) b = 0; // sample at end of read-timeslot
+ wait_us(60-15);
+ ow_pin.input();
+ return b;
+}
+/**
+* @brief read write onewire
+* @param [in] n num bus onewire
+* @param [in/out] b data
+* @return data
+* @date 30/08/2011
+*/
+uint8_t ow_bit_io(uint8_t n, uint8_t b ) {
+
+ t_ow[n]->output(); // drive bus low
+ *t_ow[n] = 0;
+ wait_us(1); // Recovery-Time wuffwuff was 1
+
+ if ( b )
+ t_ow[n]->input(); // if bit is 1 set bus high (by ext. pull-up)
+ // delay was 15uS-1 see comment above
+ wait_us(15-1);
+ if ( *t_ow[n] == 0 ) b = 0; // sample at end of read-timeslot
+ wait_us(60-15);
+ t_ow[n]->input();
+ // printf("ow_bit_io n=%d b=%X\n",n,b);
+ return b;
+}
+//**********************************************************************************************************
+//* byte write on onewire
+//**********************************************************************************************************
+/**
+* @brief byte write on onewire
+* @param [in] b data
+* @return data
+* @date 20/06/2011
+*/
+uint8_t ow_byte_wr( uint8_t b ) {
+ uint8_t i = 8, j;
+
+ do {
+ j = ow_bit_io( b & 1 );
+ b >>= 1;
+ if ( j )
+ b |= 0x80;
+ } while ( --i );
+ return b;
+}
+/**
+* @brief byte write on onewire
+* @param [in] n num bus onewire
+* @param [in] b data
+* @return data
+* @date 30/08/2011
+*/
+uint8_t ow_byte_wr(uint8_t n, uint8_t b ) {
+ uint8_t i = 8, j;
+
+ do {
+ j = ow_bit_io(n, b & 1 );
+ b >>= 1;
+ if ( j )
+ b |= 0x80;
+ } while ( --i );
+ return b;
+}
+//**********************************************************************************************************
+//* byte write on onewire
+//**********************************************************************************************************
+/**
+* @brief byte read on onewire
+* @return data
+* @date 20/06/2011
+*/
+uint8_t ow_byte_rd( void ) {
+ // read by sending 0xff (a dontcare?)
+ return ow_byte_wr( 0xFF );
+}
+
+/**
+* @brief byte read on onewire
+* @param [in] n num onewire
+* @return data
+* @date 30/08/2011
+*/
+uint8_t ow_byte_rd( uint8_t n) {
+ // read by sending 0xff (a dontcare?)
+ return ow_byte_wr(n, 0xFF );
+}
+//**********************************************************************************************************
+//* byte write on onewire
+//**********************************************************************************************************
+/**
+* @brief write command
+* @param [in] command
+* @param [in] id romcode
+* @date 20/06/2011
+*/
+uint8_t ow_command( uint8_t command, uint8_t id[] ) {
+ uint8_t i;
+
+ ow_reset();
+ if ( id ) {
+ ow_byte_wr( OW_MATCH_ROM ); // to a single device
+ i = OW_ROMCODE_SIZE;
+ do {
+ ow_byte_wr( *id );
+ ++id;
+ } while ( --i );
+ } else {
+ ow_byte_wr( OW_SKIP_ROM ); // to all devices
+ }
+ ow_byte_wr( command );
+ return 0;
+}
+/**
+* @brief write command
+* @param [in] n num bus onewire
+* @param [in] command
+* @param [in] id romcode
+* @date 30/08/2011
+*/
+uint8_t ow_command(uint8_t n, uint8_t command, uint8_t id[] ) {
+ uint8_t i;
+
+ ow_reset(n);
+ if ( id ) {
+ ow_byte_wr( n,OW_MATCH_ROM ); // to a single device
+ i = OW_ROMCODE_SIZE;
+ do {
+ ow_byte_wr(n, *id );
+ ++id;
+ } while ( --i );
+ } else {
+ ow_byte_wr(n, OW_SKIP_ROM ); // to all devices
+ }
+ ow_byte_wr(n, command );
+ return 0;
+}
+//**********************************************************************************************************
+//* ow mode
+//**********************************************************************************************************
+/**
+* @brief parasite enable
+* @date 20/06/2011
+*/
+uint8_t ow_parasite_enable(void) {
+ ow_pin.output();
+ ow_pin = 1;
+ return 0;
+}
+/**
+* @brief parasite disable
+* @date 20/06/2011
+*/
+uint8_t ow_parasite_disable(void) {
+
+ ow_pin.input();
+ return 0;
+}
+
+/**
+* @brief parasite enable
+* @param [in] n num bus onewire
+* @date 30/08/2011
+*/
+uint8_t ow_parasite_enable(uint8_t n) {
+ t_ow[n]->output();
+ *t_ow[n] = 1;
+ return 0;
+}
+/**
+* @brief parasite disable
+* @param [in] n num bus onewire
+* @date 30/08/2011
+*/
+uint8_t ow_parasite_disable(uint8_t n) {
+ t_ow[n]->input();
+ return 0;
+}
+/**
+* @brief PUL-UP bus OW
+* @return OW_OK
+* @date 20/06/2011
+*/
+uint8_t ow_PullUp(void)
+{
+ ow_pin.mode(PullUp); //PULL-UP bus OW
+return OW_OK;
+}
+/**
+* @brief PUL-UP bus OW
+* @param [in] n num bus onewire
+* @return OW_OK
+* @date 30/08/2011
+*/
+uint8_t ow_PullUp(uint8_t n)
+{
+ t_ow[n]->mode(PullUp); //PULL-UP bus OW
+return OW_OK;
+}
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