Benoit Agache
c
Diff: DS1820.cpp
- Revision:
- 5:2cd4928e8147
- Parent:
- 4:29264b0a2c9f
- Child:
- 7:58b61681818f
diff -r 29264b0a2c9f -r 2cd4928e8147 DS1820.cpp
--- 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);
}