Revision 0:a43dcf6ca539, committed 2020-12-29

Comitter:

star297

Date:

Tue Dec 29 13:08:05 2020 +0000

Child:

1:ce70453af3db

Commit message:

Initial commit

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS1820.cpp	Tue Dec 29 13:08:05 2020 +0000
@@ -0,0 +1,426 @@
+#include "DS1820.h"
+
+#ifdef TARGET_STM
+//STM targets use opendrain mode since their switching between input and output is slow
+    #define ONEWIRE_INPUT(pin)  pin->write(1)
+    #define ONEWIRE_OUTPUT(pin) 
+    #define ONEWIRE_INIT(pin)   pin->output(); pin->mode(OpenDrain)
+#else
+    #define ONEWIRE_INPUT(pin)  pin->input()
+    #define ONEWIRE_OUTPUT(pin) pin->output()
+    #define ONEWIRE_INIT(pin)
+#endif
+
+#ifdef TARGET_NORDIC
+//NORDIC targets (NRF) use software delays since their ticker uses a 32kHz clock
+    static uint32_t loops_per_us = 0;
+    
+    #define INIT_DELAY      init_soft_delay()
+    #define ONEWIRE_DELAY_US(value) for(int cnt = 0; cnt < (value * loops_per_us) >> 5; cnt++) {__NOP(); __NOP(); __NOP();}
+    
+void init_soft_delay( void ) {
+    if (loops_per_us == 0) {
+        loops_per_us = 1;
+        Timer timey; 
+        timey.start();
+        ONEWIRE_DELAY_US(320000);                     
+        timey.stop();
+        loops_per_us = (320000 + timey.read_us() / 2) / timey.read_us();  
+    }
+}
+#else
+    #define INIT_DELAY
+    #define ONEWIRE_DELAY_US(value) wait_us(value)
+#endif
+
+LinkedList2<node> DS1820::probes;
+ 
+ 
+DS1820::DS1820 (PinName data_pin, PinName power_pin, bool power_polarity) : _datapin(data_pin), _parasitepin(power_pin) {
+    int byte_counter;
+    _power_polarity = power_polarity;
+
+    _power_mosfet = power_pin != NC;
+    
+    for(byte_counter=0;byte_counter<9;byte_counter++)
+        RAM[byte_counter] = 0x00;
+    
+    ONEWIRE_INIT((&_datapin));
+    INIT_DELAY;
+    
+    if (!unassignedProbe(&_datapin, _ROM))
+        error("No unassigned DS1820 found!\n");
+    else {
+        _datapin.input();
+        probes.append(this);
+        _parasite_power = !read_power_supply();
+    }
+}
+
+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(DigitalInOut *pin) {
+// This will return false if no devices are present on the data bus
+    bool presence=false;
+    ONEWIRE_OUTPUT(pin);
+    pin->write(0);          // bring low for 500 us
+    ONEWIRE_DELAY_US(500);
+    ONEWIRE_INPUT(pin);     // let the data line float high
+    ONEWIRE_DELAY_US(90);   // wait 90us
+    if (pin->read()==0)     // see if any devices are pulling the data line low
+        presence=true;
+    ONEWIRE_DELAY_US(410);
+    return presence;
+}
+ 
+void DS1820::onewire_bit_out (DigitalInOut *pin, bool bit_data) {
+    ONEWIRE_OUTPUT(pin);
+    pin->write(0);
+    ONEWIRE_DELAY_US(3);        // DXP modified from 5
+    if (bit_data) {
+        pin->write(1);          // bring data line high
+        ONEWIRE_DELAY_US(55);
+    } else {
+        ONEWIRE_DELAY_US(55);   // keep data line low
+        pin->write(1);
+        ONEWIRE_DELAY_US(10);   // DXP added to allow bus to float high before next bit_out
+    }
+}
+ 
+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(&this->_datapin, data & 0x01);
+        data = data >> 1;       // now the next bit is in the least sig bit position.
+    }
+}
+ 
+bool DS1820::onewire_bit_in(DigitalInOut *pin) {
+    bool answer;
+    ONEWIRE_OUTPUT(pin);
+    pin->write(0);
+    ONEWIRE_DELAY_US(3);    // DXP modofied from 5
+    ONEWIRE_INPUT(pin);
+    ONEWIRE_DELAY_US(6);    // DXP modified from 5
+    answer = pin->read();
+    ONEWIRE_DELAY_US(45);   // DXP modified from 50
+    return answer;
+}
+ 
+char DS1820::onewire_byte_in() { // read byte, least sig byte first
+    char answer = 0x00;
+    int i;
+    for (i=0; i<8; i++) {
+        answer = answer >> 1; // shift over to make room for the next bit
+        if (onewire_bit_in(&this->_datapin))
+            answer = answer | 0x80; // if the data port is high, make this bit a 1
+    }
+    return answer;
+}
+
+bool DS1820::unassignedProbe(PinName pin) {
+    DigitalInOut _pin(pin);
+    ONEWIRE_INIT((&_pin));
+    INIT_DELAY;
+    char ROM_address[8];
+    return search_ROM_routine(&_pin, 0xF0, ROM_address);
+}
+ 
+bool DS1820::unassignedProbe(DigitalInOut *pin, char *ROM_address) {
+    return search_ROM_routine(pin, 0xF0, ROM_address);
+}
+ 
+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;
+    while (!DS1820_done_flag) {
+        if (!onewire_reset(pin)) {
+            return false;
+        } else {
+            ROM_bit_index=1;
+            descrepancy_marker=0;
+            char command_shift = command;
+            for (int n=0; n<8; n++) {           // Search ROM command or Search Alarm command
+                onewire_bit_out(pin, command_shift & 0x01);
+                command_shift = command_shift >> 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(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;
+                } else {
+                    if (Bit_A | Bit_B) {
+                        // Set ROM bit to Bit_A
+                        if (Bit_A) {
+                            DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one
+                        } else {
+                            DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero
+                        }
+                    } else {
+                        // both bits A and B are low, so there are two or more devices present
+                        if ( ROM_bit_index == DS1820_last_descrepancy ) {
+                            DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one
+                        } else {
+                            if ( ROM_bit_index > DS1820_last_descrepancy ) {
+                                DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero
+                                descrepancy_marker = ROM_bit_index;
+                            } else {
+                                if (( DS1820_search_ROM[byte_counter] & bit_mask) == 0x00 )
+                                    descrepancy_marker = ROM_bit_index;
+                            }
+                        }
+                    }
+                    onewire_bit_out (pin, DS1820_search_ROM[byte_counter] & bit_mask);
+                    ROM_bit_index++;
+                    if (bit_mask & 0x80) {
+                        byte_counter++;
+                        bit_mask = 0x01;
+                    } else {
+                        bit_mask = bit_mask << 1;
+                    }
+                }
+            }
+            DS1820_last_descrepancy = descrepancy_marker;
+            if (ROM_bit_index != 0xFF) {
+                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)
+            DS1820_done_flag = true;
+    }
+    return return_value;
+}
+ 
+void DS1820::match_ROM() {
+// Used to select a specific device
+    int i;
+    onewire_reset(&this->_datapin);
+    onewire_byte_out( 0x55);  //Match ROM command
+    for (i=0;i<8;i++) {
+        onewire_byte_out(_ROM[i]);
+    }
+}
+ 
+void DS1820::skip_ROM() {
+    onewire_reset(&this->_datapin);
+    onewire_byte_out(0xCC);   // Skip ROM command
+}
+ 
+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_address[i]);
+    // After 7 bytes CRC should equal the 8th byte (ROM CRC)
+    return (_CRC!=_ROM_address[7]); // will return true if there is a CRC checksum mis-match         
+}
+ 
+bool DS1820::RAM_checksum_error() {
+    char _CRC=0x00;
+    int i;
+    for(i=0;i<8;i++) // Only going to shift the lower 8 bytes
+        _CRC = CRC_byte(_CRC, RAM[i]);
+    // After 8 bytes CRC should equal the 9th byte (RAM CRC)
+    return (_CRC!=RAM[8]); // will return true if there is a CRC checksum mis-match        
+}
+ 
+char DS1820::CRC_byte (char _CRC, char byte ) {
+    int j;
+    for(j=0;j<8;j++) {
+        if ((byte & 0x01 ) ^ (_CRC & 0x01)) {
+            // DATA ^ LSB CRC = 1
+            _CRC = _CRC>>1;
+            // Set the MSB to 1
+            _CRC = _CRC | 0x80;
+            // Check bit 3
+            if (_CRC & 0x04) {
+                _CRC = _CRC & 0xFB; // Bit 3 is set, so clear it
+            } else {
+                _CRC = _CRC | 0x04; // Bit 3 is clear, so set it
+            }
+            // Check bit 4
+            if (_CRC & 0x08) {
+                _CRC = _CRC & 0xF7; // Bit 4 is set, so clear it
+            } else {
+                _CRC = _CRC | 0x08; // Bit 4 is clear, so set it
+            }
+        } else {
+            // DATA ^ LSB CRC = 0
+            _CRC = _CRC>>1;
+            // clear MSB
+            _CRC = _CRC & 0x7F;
+            // No need to check bits, with DATA ^ LSB CRC = 0, they will remain unchanged
+        }
+        byte = byte>>1;
+    }
+return _CRC;
+}
+ 
+int DS1820::convertTemperature(bool wait, devices device) {
+    // Convert temperature into scratchpad RAM for all devices at once
+    int delay_time = 750000; // Default delay time
+    char resolution;
+    if (device==all_devices)
+        skip_ROM();          // Skip ROM command, will convert for ALL devices
+    else {
+        match_ROM();
+        if ((FAMILY_CODE == FAMILY_CODE_DS18B20 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
+            resolution = RAM[4] & 0x60;
+            if (resolution == 0x00) // 9 bits
+                delay_time = 94000;
+            if (resolution == 0x20) // 10 bits
+                delay_time = 188000;
+            if (resolution == 0x40) // 11 bits. Note 12bits uses the 750ms default
+                delay_time = 375000;
+        }
+    }
+    
+    onewire_byte_out( 0x44);  // perform temperature conversion
+    if (_parasite_power) {
+        if (_power_mosfet) {
+            _parasitepin = _power_polarity;     // Parasite power strong pullup
+            wait_us(delay_time);
+            _parasitepin = !_power_polarity;
+            delay_time = 0;
+        } else {
+            _datapin.output();
+            _datapin.write(1);
+            wait_us(delay_time);
+            _datapin.input();
+        }
+    } else {
+        if (wait) {
+            wait_us(delay_time);
+            delay_time = 0;
+        }
+    }
+    return delay_time;
+}
+ 
+void DS1820::read_RAM() {
+    // This will copy the DS1820's 9 bytes of RAM data
+    // into the objects RAM array. Functions that use
+    // RAM values will automaticly call this procedure.
+    int i;
+    match_ROM();             // Select this device
+    onewire_byte_out( 0xBE);   //Read Scratchpad command
+    for(i=0;i<9;i++) {
+        RAM[i] = onewire_byte_in();
+    }
+//    if (!RAM_checksum_error())
+//       crcerr = 1;
+}
+
+bool DS1820::setResolution(unsigned int resolution) {
+    bool answer = false;
+    resolution = resolution - 9;
+    if (resolution < 4) {
+        resolution = resolution<<5; // align the bits
+        RAM[4] = (RAM[4] & 0x60) | resolution; // mask out old data, insert new
+        write_scratchpad ((RAM[2]<<8) + RAM[3]);
+        write_scratchpad (DS1820::this_device); // Need to test if this is required
+        answer = true;
+    }
+    return answer;
+}
+ 
+void DS1820::write_scratchpad(int data) {
+    RAM[3] = data;
+    RAM[2] = data>>8;
+    match_ROM();
+    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 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
+        onewire_byte_out(RAM[4]); // Configuration register
+    }
+}
+ 
+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
+// this allowed an expanded resolution of 1/150th of a deg C. I wouldn't rely on this
+// being super acurate, but it does allow for a smooth display in the 1/10ths of a
+// deg C or F scales.
+    float answer, remaining_count, count_per_degree;
+    int reading;
+    read_RAM();
+    if (RAM_checksum_error())
+        // Indicate we got a CRC error
+        answer = invalid_conversion;
+    else {
+        reading = (RAM[1] << 8) + RAM[0];
+        if (reading & 0x8000) { // negative degrees C
+            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 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
+            answer = answer / 16.0f;
+        }
+        else {
+            remaining_count = RAM[6];
+            count_per_degree = RAM[7];
+            answer = floor(answer/2.0f) - 0.25f + (count_per_degree - remaining_count) / count_per_degree;
+        }
+        if (scale=='F' or scale=='f')
+            // Convert to deg F
+            answer = answer * 9.0f / 5.0f + 32.0f;
+    }
+    return answer;
+}
+ 
+bool DS1820::read_power_supply(devices device) {
+// This will return true if the device (or all devices) are Vcc powered
+// This will return false if the device (or ANY device) is parasite powered
+    if (device==all_devices)
+        skip_ROM();          // Skip ROM command, will poll for any device using parasite power
+    else
+        match_ROM();
+    onewire_byte_out(0xB4);   // Read power supply command
+    return onewire_bit_in(&this->_datapin);
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DS1820.h	Tue Dec 29 13:08:05 2020 +0000
@@ -0,0 +1,120 @@
+
+#ifndef MBED_DS1820_H
+#define MBED_DS1820_H
+
+#include "mbed.h"
+#include "LinkedList2.h"
+
+#define FAMILY_CODE _ROM[0]
+#define FAMILY_CODE_DS1820 0x10
+#define FAMILY_CODE_DS18B20 0x28
+#define FAMILY_CODE_DS1822  0x22
+
+/** DS1820 Dallas 1-Wire Temperature Probe
+ *
+ * Example for single sensor:
+ * @code
+ * #include "mbed.h"
+ * #include "DS1820.h"
+ *
+ * DS1820 probe(DATA_PIN);
+ *  
+ * int main() {
+ *     while(1) {
+ *         probe.convertTemperature(true, DS1820::all_devices); //Start temperature conversion, wait until completed
+ *         printf("It is %3.1foC\r\n", probe.temperature());
+ *         ThisThread::sleep_for(chrono::milliseconds(1000));
+ *     }
+ * }
+ * @endcode
+ */
+class DS1820 {
+public:
+    enum devices{
+        this_device,     // command applies to only this device
+        all_devices };   // command applies to all devices
+    
+    enum {
+        invalid_conversion = -1000
+    };
+
+    /** Create a probe object connected to the specified pins
+    *
+    * The probe might either by regular powered or parasite powered. If it is parasite
+    * powered and power_pin is set, that pin will be used to switch an external mosfet connecting
+    * data to Vdd. If it is parasite powered and the pin is not set, the regular data pin
+    * is used to supply extra power when required. This will be sufficient as long as the 
+    * number of probes is limitted.
+     *
+     * @param data_pin DigitalInOut pin for the data bus
+     * @param power_pin DigitalOut (optional) pin to control the power MOSFET
+     * @param power_polarity bool (optional) which sets active state (0 for active low (default), 1 for active high)
+     */
+    DS1820(PinName data_pin, PinName power_pin = NC, bool power_polarity = 0); // Constructor with parasite power pin
+    ~DS1820();
+
+    /** Function to see if there are DS1820 devices left on a pin which do not have a corresponding DS1820 object
+    *
+    * @return - true if there are one or more unassigned devices, otherwise false
+      */
+    static bool unassignedProbe(PinName pin);
+
+    /** This routine will initiate the temperature conversion within
+      * one or all DS1820 probes. 
+      *
+      * @param wait if true or parisitic power is used, waits up to 750 ms for 
+      * conversion otherwise returns immediatly.
+      * @param device allows the function to apply to a specific device or
+      * to all devices on the 1-Wire bus.
+      * @returns milliseconds untill conversion will complete.
+      */
+    int convertTemperature(bool wait, devices device=all_devices);
+
+    /** This function will return the probe temperature. Approximately 10ms per
+      * probe to read its RAM, do CRC check and convert temperature on the LPC1768.
+      *
+      * @param scale, may be either 'c' or 'f'
+      * @returns temperature for that scale, or DS1820::invalid_conversion (-1000) if CRC error detected.
+      */
+    float temperature(char scale='c');
+
+    /** This function sets the temperature resolution for the DS18B20
+      * in the configuration register.
+      *
+      * @param a number between 9 and 12 to specify resolution
+      * @returns true if successful
+      */ 
+    bool setResolution(unsigned int resolution);  
+    
+    static LinkedList2<node> probes;     
+
+private:
+    bool _parasite_power;
+    bool _power_mosfet;
+    bool _power_polarity;
+    
+    static char CRC_byte(char _CRC, char byte );
+    static bool onewire_reset(DigitalInOut *pin);
+    void match_ROM();
+    void skip_ROM();
+    static bool search_ROM_routine(DigitalInOut *pin, char command, char *ROM_address);
+    static void onewire_bit_out (DigitalInOut *pin, bool bit_data);
+    void onewire_byte_out(char data);
+    static bool onewire_bit_in(DigitalInOut *pin);
+    char onewire_byte_in();
+    static bool ROM_checksum_error(char *_ROM_address);
+    bool RAM_checksum_error();
+    void read_RAM();
+    static bool unassignedProbe(DigitalInOut *pin, char *ROM_address);
+    void write_scratchpad(int data);
+    bool read_power_supply(devices device=this_device);
+
+    DigitalInOut _datapin;
+    DigitalOut _parasitepin;
+    
+    char _ROM[8];
+    char RAM[9];
+};
+
+
+#endif
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/LinkedList2.lib	Tue Dec 29 13:08:05 2020 +0000
@@ -0,0 +1,1 @@
+LinkedList2#27649dfdde4c