Diff: DS1820.cpp

Revision:

5:2cd4928e8147

Parent:

4:29264b0a2c9f

Child:

7:58b61681818f

--- a/DS1820.cpp	Wed Aug 07 11:02:10 2013 +0000
+++ b/DS1820.cpp	Mon Feb 24 21:23:14 2014 +0000
@@ -1,53 +1,61 @@
 #include "DS1820.h"
-#include "mbed.h"
- 
-// Global variables shared between all DS1820 objects
-bool DS1820_done_flag;
-int  DS1820_last_descrepancy;
-char DS1820_search_ROM[8];
+
+LinkedList<node> DS1820::probes;
  
  
-DS1820::DS1820 (PinName data_pin, PinName power_pin) : _datapin(data_pin), _parasitepin(power_pin) {
+DS1820::DS1820 (PinName data_pin, PinName power_pin, bool power_polarity) : _datapin(data_pin), _parasitepin(power_pin) {
     int byte_counter;
-    _parasite_power = true;
-    for(byte_counter=0;byte_counter<8;byte_counter++)
-        ROM[byte_counter] = 0xFF;
+    _power_polarity = power_polarity;
+    if (power_pin != NC)
+        _power_mosfet = true;
+    
     for(byte_counter=0;byte_counter<9;byte_counter++)
         RAM[byte_counter] = 0x00;
+    
+    if (!unassignedProbe(&_datapin, _ROM))
+        error("No unassigned DS1820 found!\n");
+    else {
+        _datapin.input();
+        probes.append(this);
+        _parasite_power = !read_power_supply();
+    }
 }
-DS1820::DS1820 (PinName data_pin) : _datapin(data_pin), _parasitepin(NC) {
-    int byte_counter;
-    _parasite_power = false;
-    for(byte_counter=0;byte_counter<8;byte_counter++)
-        ROM[byte_counter] = 0xFF;
-    for(byte_counter=0;byte_counter<9;byte_counter++)
-        RAM[byte_counter] = 0x00;
+
+DS1820::~DS1820 (void) {
+    node *tmp;
+    for(int i=1; i<=probes.length(); i++)
+    {
+        tmp = probes.pop(i);
+        if (tmp->data == this)
+            probes.remove(i);
+    }
 }
+
  
-bool DS1820::onewire_reset() {
+bool DS1820::onewire_reset(DigitalInOut *pin) {
 // This will return false if no devices are present on the data bus
     bool presence=false;
-    _datapin.output();
-    _datapin = 0;           // bring low for 500 us
+    pin->output();
+    pin->write(0);          // bring low for 500 us
     wait_us(500);
-    _datapin.input();       // let the data line float high
+    pin->input();       // let the data line float high
     wait_us(90);            // wait 90us
-    if (_datapin.read()==0) // see if any devices are pulling the data line low
+    if (pin->read()==0) // see if any devices are pulling the data line low
         presence=true;
     wait_us(410);
     return presence;
 }
  
-void DS1820::onewire_bit_out (bool bit_data) {
-    _datapin.output();
-    _datapin = 0;
+void DS1820::onewire_bit_out (DigitalInOut *pin, bool bit_data) {
+    pin->output();
+    pin->write(0);
     wait_us(3);                 // DXP modified from 5
     if (bit_data) {
-        _datapin.input(); // bring data line high
+        pin->input(); // bring data line high
         wait_us(55);
     } else {
         wait_us(55);            // keep data line low
-        _datapin.input();
+        pin->input();
         wait_us(10);            // DXP added to allow bus to float high before next bit_out
     }
 }
@@ -55,19 +63,19 @@
 void DS1820::onewire_byte_out(char data) { // output data character (least sig bit first).
     int n;
     for (n=0; n<8; n++) {
-        onewire_bit_out(data & 0x01);
+        onewire_bit_out(&this->_datapin, data & 0x01);
         data = data >> 1; // now the next bit is in the least sig bit position.
     }
 }
  
-bool DS1820::onewire_bit_in() {
+bool DS1820::onewire_bit_in(DigitalInOut *pin) {
     bool answer;
-    _datapin.output();
-    _datapin = 0;
+    pin->output();
+    pin->write(0);
     wait_us(3);                 // DXP modofied from 5
-    _datapin.input();
+    pin->input();
     wait_us(10);                // DXP modified from 5
-    answer = _datapin.read();
+    answer = pin->read();
     wait_us(45);                // DXP modified from 50
     return answer;
 }
@@ -77,41 +85,47 @@
     int i;
     for (i=0; i<8; i++) {
         answer = answer >> 1; // shift over to make room for the next bit
-        if (onewire_bit_in())
+        if (onewire_bit_in(&this->_datapin))
             answer = answer | 0x80; // if the data port is high, make this bit a 1
     }
     return answer;
 }
- 
-bool DS1820::search_ROM() {
-    return search_ROM_routine(0xF0);    // Search ROM command
+
+bool DS1820::unassignedProbe(PinName pin) {
+    DigitalInOut _pin(pin);
+    char ROM_address[8];
+    return search_ROM_routine(&_pin, 0xF0, ROM_address);
 }
  
-bool DS1820::search_alarm() {
-    return search_ROM_routine(0xEC);    // Search Alarm command
+bool DS1820::unassignedProbe(DigitalInOut *pin, char *ROM_address) {
+    return search_ROM_routine(pin, 0xF0, ROM_address);
 }
  
-bool DS1820::search_ROM_routine(char command) {
-    extern bool DS1820_done_flag;
-    extern int DS1820_last_descrepancy;
-    extern char DS1820_search_ROM[8];
+bool DS1820::search_ROM_routine(DigitalInOut *pin, char command, char *ROM_address) {
+    bool DS1820_done_flag = false;
+    int DS1820_last_descrepancy = 0;
+    char DS1820_search_ROM[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+    
     int descrepancy_marker, ROM_bit_index;
     bool return_value, Bit_A, Bit_B;
     char byte_counter, bit_mask;
  
     return_value=false;
-    if (!DS1820_done_flag) {
-        if (!onewire_reset()) {
-            DS1820_last_descrepancy = 0; // no devices present
+    while (!DS1820_done_flag) {
+        if (!onewire_reset(pin)) {
+            return false;
         } else {
             ROM_bit_index=1;
             descrepancy_marker=0;
-            onewire_byte_out(command); // Search ROM command or Search Alarm command
+            for (int n=0; n<8; n++) {           // Search ROM command or Search Alarm command
+                onewire_bit_out(pin, command & 0x01);
+                command = command >> 1; // now the next bit is in the least sig bit position.
+            } 
             byte_counter = 0;
             bit_mask = 0x01;
             while (ROM_bit_index<=64) {
-                Bit_A = onewire_bit_in();
-                Bit_B = onewire_bit_in();
+                Bit_A = onewire_bit_in(pin);
+                Bit_B = onewire_bit_in(pin);
                 if (Bit_A & Bit_B) {
                     descrepancy_marker = 0; // data read error, this should never happen
                     ROM_bit_index = 0xFF;
@@ -137,7 +151,7 @@
                             }
                         }
                     }
-                    onewire_bit_out (DS1820_search_ROM[byte_counter] & bit_mask);
+                    onewire_bit_out (pin, DS1820_search_ROM[byte_counter] & bit_mask);
                     ROM_bit_index++;
                     if (bit_mask & 0x80) {
                         byte_counter++;
@@ -149,12 +163,32 @@
             }
             DS1820_last_descrepancy = descrepancy_marker;
             if (ROM_bit_index != 0xFF) {
-                for(byte_counter=0;byte_counter<8;byte_counter++)
-                    ROM[byte_counter] = DS1820_search_ROM[byte_counter];
-                if (ROM_checksum_error())           // Check the CRC
-                    DS1820_last_descrepancy = 0;    // Abort any more search
-                else
-                    return_value = true;
+                int i = 1;
+                node *list_container;
+                while(1) {
+                    list_container = probes.pop(i);
+                    if (list_container == NULL) {                             //End of list, or empty list
+                        if (ROM_checksum_error(DS1820_search_ROM)) {          // Check the CRC
+                            return false;
+                        }
+                        for(byte_counter=0;byte_counter<8;byte_counter++)
+                            ROM_address[byte_counter] = DS1820_search_ROM[byte_counter];
+                        return true;
+                    } else {                    //Otherwise, check if ROM is already known
+                        bool equal = true;
+                        DS1820 *pointer = (DS1820*) list_container->data;
+                        char *ROM_compare = pointer->_ROM;
+                        
+                        for(byte_counter=0;byte_counter<8;byte_counter++) {
+                            if ( ROM_compare[byte_counter] != DS1820_search_ROM[byte_counter])
+                                equal = false;
+                        }
+                        if (equal)
+                            break;
+                        else
+                            i++;
+                    }
+                }                        
             }
         }
         if (DS1820_last_descrepancy == 0)
@@ -163,49 +197,28 @@
     return return_value;
 }
  
-void DS1820::search_ROM_setup() {
-    extern bool DS1820_done_flag;
-    extern int DS1820_last_descrepancy;
-    extern char DS1820_search_ROM[8];
-    DS1820_done_flag = false;
-    DS1820_last_descrepancy = 0;
-    int i;
-    for (i=0; i<8; i++)
-        DS1820_search_ROM[i]=0x00;
-}
- 
-void DS1820::read_ROM() {
-    // NOTE: This command can only be used when there is one DS1820 on the bus. If this command
-    // is used when there is more than one slave present on the bus, a data collision will occur
-    // when all the DS1820s attempt to respond at the same time.
-    int i;
-    onewire_reset();
-    onewire_byte_out(0x33);   // Read ROM id
-    for (i=0; i<8; i++)
-        ROM[i]=onewire_byte_in();
-}
- 
 void DS1820::match_ROM() {
 // Used to select a specific device
     int i;
-    onewire_reset();
+    onewire_reset(&this->_datapin);
     onewire_byte_out( 0x55);  //Match ROM command
-    for (i=0;i<8;i++)
-        onewire_byte_out(ROM[i]);
+    for (i=0;i<8;i++) {
+        onewire_byte_out(_ROM[i]);
+    }
 }
  
 void DS1820::skip_ROM() {
-    onewire_reset();
+    onewire_reset(&this->_datapin);
     onewire_byte_out(0xCC);   // Skip ROM command
 }
  
-bool DS1820::ROM_checksum_error() {
+bool DS1820::ROM_checksum_error(char *_ROM_address) {
     char CRC=0x00;
     int i;
     for(i=0;i<7;i++) // Only going to shift the lower 7 bytes
-        CRC = CRC_byte(CRC, ROM[i]);
+        CRC = CRC_byte(CRC, _ROM_address[i]);
     // After 7 bytes CRC should equal the 8th byte (ROM CRC)
-    return (CRC!=ROM[7]); // will return true if there is a CRC checksum mis-match         
+    return (CRC!=_ROM_address[7]); // will return true if there is a CRC checksum mis-match         
 }
  
 bool DS1820::RAM_checksum_error() {
@@ -249,7 +262,7 @@
 return CRC;
 }
  
-int DS1820::convert_temperature(bool wait, devices device) {
+int DS1820::convertTemperature(bool wait, devices device) {
     // Convert temperature into scratchpad RAM for all devices at once
     int delay_time = 750; // Default delay time
     char resolution;
@@ -257,7 +270,7 @@
         skip_ROM();          // Skip ROM command, will convert for ALL devices
     else {
         match_ROM();
-        if (FAMILY_CODE == FAMILY_CODE_DS18B20 ) {
+        if ((FAMILY_CODE == FAMILY_CODE_DS18B20 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
             resolution = RAM[4] & 0x60;
             if (resolution == 0x00) // 9 bits
                 delay_time = 94;
@@ -267,12 +280,20 @@
                 delay_time = 375;
         }
     }
+    
     onewire_byte_out( 0x44);  // perform temperature conversion
     if (_parasite_power) {
-        _parasitepin = 1;     // Parasite power strong pullup
-        wait_ms(delay_time);
-        _parasitepin = 0;
-        delay_time = 0;
+        if (_power_mosfet) {
+            _parasitepin = _power_polarity;     // Parasite power strong pullup
+            wait_ms(delay_time);
+            _parasitepin = !_power_polarity;
+            delay_time = 0;
+        } else {
+            _datapin.output();
+            _datapin.write(1);
+            wait_ms(delay_time);
+            _datapin.input();
+        }
     } else {
         if (wait) {
             wait_ms(delay_time);
@@ -296,7 +317,7 @@
 //       crcerr = 1;
 }
 
-bool DS1820::set_configuration_bits(unsigned int resolution) {
+bool DS1820::setResolution(unsigned int resolution) {
     bool answer = false;
     resolution = resolution - 9;
     if (resolution < 4) {
@@ -309,13 +330,6 @@
     return answer;
 }
  
-int DS1820::read_scratchpad() {
-    int answer;
-    read_RAM();
-    answer = (RAM[2]<<8) + RAM[3];
-    return answer;
-}
- 
 void DS1820::write_scratchpad(int data) {
     RAM[3] = data;
     RAM[2] = data>>8;
@@ -323,43 +337,11 @@
     onewire_byte_out(0x4E);   // Copy scratchpad into DS1820 ram memory
     onewire_byte_out(RAM[2]); // T(H)
     onewire_byte_out(RAM[3]); // T(L)
-    if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) {
+    if ((FAMILY_CODE == FAMILY_CODE_DS18B20 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
         onewire_byte_out(RAM[4]); // Configuration register
     }
 }
  
-void DS1820::store_scratchpad(devices device) {
-    if (device==all_devices)
-        skip_ROM();          // Skip ROM command, will store for ALL devices
-    else
-        match_ROM();
-    onewire_byte_out(0x48);   // Write scratchpad into E2 command
-    if (_parasite_power)
-        _parasitepin=1;
-    wait_ms(10);            // Parasite power strong pullup for 10ms
-    if (_parasite_power)
-        _parasitepin=0;
-}
- 
-int DS1820::recall_scratchpad(devices device) {
-// This copies the E2 values into the DS1820's memory.
-// If you specify all_devices this will return zero, otherwise
-// it will return the value of the scratchpad memory.
-    int answer=0;
-    if (device==all_devices)
-        skip_ROM();          // Skip ROM command, will recall for ALL devices
-    else
-        match_ROM();
-    onewire_byte_out(0xB8);   // Recall E2 data to scratchpad command
-    wait_ms(10); // not sure I like polling for completion
-                 // it could cause an infinite loop
-    if (device==DS1820::this_device) {
-        read_RAM();
-        answer = read_scratchpad();
-    }
-    return answer;
-}    
- 
 float DS1820::temperature(char scale) {
 // The data specs state that count_per_degree should be 0x10 (16), I found my devices
 // to have a count_per_degree of 0x4B (75). With the standard resolution of 1/2 deg C
@@ -378,7 +360,7 @@
             reading = 0-((reading ^ 0xffff) + 1); // 2's comp then convert to signed int
         }
         answer = reading +0.0; // convert to floating point
-        if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) {
+        if ((FAMILY_CODE == FAMILY_CODE_DS18B20 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
             answer = answer / 8.0;
         }
         else {
@@ -403,7 +385,7 @@
     else
         match_ROM();
     onewire_byte_out(0xB4);   // Read power supply command
-    return onewire_bit_in();
+    return onewire_bit_in(&this->_datapin);
 }