Zoltan Hudak
Dallas' DS1820 family temperature sensor. For more details see [https://developer.mbed.org/users/hudakz/code/DS1820/wiki/Homepage]
Dependents: BLE_nRF24L01 frdm_serialfgmp gather_sensor_data UltiSaverController ... more
Some programs using the DS1820 library:
Import programDS1820_Hello
Simple DS1820 sensor demo showing how to use the DS1820 library [https://developer.mbed.org/users/hudakz/code/DS1820/]
Last commit 20 Jul 2020 by 
Zoltan Hudak
Import programBLE_nRF24L01
Bluetooth Low Energy (BLE) beacon with nRF24L01(+). Data is received and displayed by Android device (Android app source code is attached).
Last commit 26 Jan 2016 by Zoltan Hudak
Examples of use:
Single DS1820 sensor
/*
* Single DS1820 sensor GPIO driven
*
* Note: Don't forget to connect a 4.7k Ohm resistor
* between the DS1820's data pin and the +3.3V pin
*
* ----------------
* | | -----------------------> +3.3V
* | MBED BOARD | |
* | | | ------
* | +3.3V |--o--| 4.7k |-------
* | | ------ |
* | | |
* | | |
* | | |
* | | |
* | GPIO |--------------------o-----> 1-wire bus/line
* | |
* | |
* | GND |--------------------------> GND
* | |
* ----------------
*
*/
#include "mbed.h"
#include "DS1820.h"
Serial serial(USBTX, USBRX);
int main() {
DS1820 ds1820(D8); // substitute D8 with actual mbed pin name connected to the DS1820 data pin
if(ds1820.begin()) {
while(1) {
ds1820.startConversion(); // start temperature conversion
ThisThread::sleep_for(1000); // let DS1820 complete the temperature conversion
serial.printf("temp = %3.1f\r\n", ds1820.read()); // read temperature
}
} else
serial.printf("No DS1820 sensor found!\r\n");
}
Single DS1820 sensor. Data integrity is assured by performing CRC.
/*
* Single DS1820 sensor GPIO driven + performing CRC
*
* Note: Don't forget to connect a 4.7k Ohm resistor
* between the DS1820's data pin and the +3.3V pin
*
* ----------------
* | | -----------------------> +3.3V
* | MBED BOARD | |
* | | | ------
* | +3.3V |--o--| 4.7k |-------
* | | ------ |
* | | |
* | | |
* | | |
* | | |
* | GPIO |--------------------o-----> 1-wire bus/line
* | |
* | |
* | GND |--------------------------> GND
* | |
* ----------------
*
*/
#include "mbed.h"
#include "DS1820.h"
Serial serial(USBTX, USBRX);
int main() {
DS1820 ds1820(D8); // substitute D8 with actual mbed pin name connected to the DS1820 data pin
float temp = 0;
int error = 0;
if(ds1820.begin()) {
while(1) {
ds1820.startConversion(); // start temperature conversion
ThisThread::sleep_for(1000); // let DS1820 complete the temperature conversion
error = ds1820.read(temp); // read temperature from DS1820 and perform cyclic redundancy check (CRC)
switch(error) {
case 0: // no errors -> 'temp' contains the value of measured temperature
serial.printf("temp = %3.1f\r\n", temp);
break;
case 1: // no sensor present -> 'temp' is not updated
serial.printf("no sensor present\n\r");
break;
case 2: // CRC error -> 'temp' is not updated
serial.printf("CRC error\r\n");
}
}
} else
serial.printf("No DS1820 sensor found!\r\n");
}
Several DS1820 sensors connected to the same 1-wire bus.
/*
* Multiple sensors GPIO driven
*
* Note: Don't forget to connect a 4.7k Ohm resistor
* between the 1-wire bus data line and the +3.3V rail
*
* ----------------
* | | -----------------------> +3.3V
* | MBED BOARD | |
* | | | ------
* | +3.3V |--o--| 4.7k |-------
* | | ------ |
* | | |
* | | |
* | | |
* | | |
* | GPIO |--------------------o-----> 1-wire bus/line
* | |
* | |
* | GND |--------------------------> GND
* | |
* ----------------
*
*/
#include "mbed.h"
#include "DS1820.h"
#define MAX_SENSOSRS 32 // max number of DS1820 sensors to be connected to the 1-wire bus (max 256)
DS1820* ds1820[MAX_SENSOSRS];
Serial pc(USBTX, USBRX);
DigitalOut led(LED1);
OneWire oneWire(D8); // substitute D8 with the actual pin name connected to the 1-wire bus
int sensorsFound = 0; // counts the actually found DS1820 sensors
int main()
{
pc.printf("\r\n--Starting--\r\n");
//Enumerate (i.e. detect) DS1820 sensors on the 1-wire bus
for (sensorsFound = 0; sensorsFound < MAX_SENSOSRS; sensorsFound++) {
ds1820[sensorsFound] = new DS1820(&oneWire);
if (!ds1820[sensorsFound]->begin()) {
delete ds1820[sensorsFound];
break;
}
}
switch (sensorsFound) {
case 0:
pc.printf("No DS1820 sensor found!\r\n");
return -1;
case 1:
pc.printf("One DS1820 sensor found.\r\n");
break;
default:
pc.printf("Found %d DS1820 sensors.\r\n", sensorsFound);
}
while (1) {
pc.printf("----------------\r\n");
for (int i = 0; i < sensorsFound; i++)
ds1820[i]->startConversion(); // start temperature conversion from analog to digital
ThisThread::sleep_for(1000); // let DS1820 sensors complete the temperature conversion
for (int i = 0; i < sensorsFound; i++) {
if (ds1820[i]->isPresent())
pc.printf("temp[%d] = %3.1f%cC\r\n", i, ds1820[i]->read(), 176); // read temperature
}
}
}
Several DS1820 sensors connected to the same 1-wire bus. UART is used to implement the bus
/*
* Multiple sensors UART driven:
*
* UART is driving the 1-Wire Bus Master according to Maxim Integrated application note
*
* https://www.maximintegrated.com/en/design/technical-documents/tutorials/2/214.html
*
* In addition to the 4.7k Ohm resistor between the 1-wire data bus/line and the +3.3V pin,
* a 470 Ohm resistor shall be tied to the UART's tx and rx pin. UART's rx pin is then used
* as 1-wire data bus/line.
*
* ----------------
* | | -----------------------> +3.3V
* | MBED BOARD | |
* | | | ------
* | +3.3V |--o--| 4.7k |-------
* | | ------ |
* | | ------ |
* | UART TX |-----| 470 |--- |
* | | ------ | |
* | | | |
* | UART RX |----------------o---o-----> 1-wire bus/line
* | |
* | |
* | GND |--------------------------> GND
* | |
* ----------------
*
*/
#include "mbed.h"
#include "DS1820.h"
#define MAX_SENSOSRS 32 // max number of DS1820 sensors to be connected to the 1-wire bus (max 256)
DS1820* ds1820[MAX_SENSOSRS];
DigitalOut led(LED1);
OneWire oneWire(p9, p10); // LPC1768 (UART Tx pin, UART Rx pin)
//OneWire oneWire(PA_0, PA_1); // NUCLE0-F446RE (UART Tx pin, UART Rx pin)
int sensorsFound = 0; // counts the actually found DS1820 sensors
/**
* @brief
* @note
* @param
* @retval
*/
int main()
{
printf("\r\n--Starting--\r\n");
//Enumerate (i.e. detect) DS1820 sensors on the 1-wire bus
for (sensorsFound = 0; sensorsFound < MAX_SENSOSRS; sensorsFound++) {
ds1820[sensorsFound] = new DS1820(&oneWire);
if (!ds1820[sensorsFound]->begin()) {
delete ds1820[sensorsFound];
break;
}
}
switch (sensorsFound) {
case 0:
printf("No DS1820 sensor found!\r\n");
return -1;
case 1:
printf("One DS1820 sensor found.\r\n");
break;
default:
printf("Found %d DS1820 sensors.\r\n", sensorsFound);
}
while (1) {
led = !led;
printf("----------------\r\n");
for (int i = 0; i < sensorsFound; i++)
ds1820[i]->startConversion(); // start temperature conversion from analog to digital
#if (MBED_MAJOR_VERSION > 5)
ThisThread::sleep_for(1s);
#else
wait(1);
#endif
for (int i = 0; i < sensorsFound; i++) {
if (ds1820[i]->isPresent())
printf("temp[%d] = %3.1f%cC\r\n", i, ds1820[i]->read(), 176); // read temperature
}
}
}
Revision 24:d683d826dccd, committed 2020-12-28
- Comitter:
- hudakz
- Date:
- Mon Dec 28 21:15:27 2020 +0000
- Parent:
- 23:74a4ff420541
- Commit message:
- DS1820: Added 1-wire bus implementation over UART.
Changed in this revision
diff -r 74a4ff420541 -r d683d826dccd DS1820.cpp
--- a/DS1820.cpp Mon Jul 20 08:09:58 2020 +0000
+++ b/DS1820.cpp Mon Dec 28 21:15:27 2020 +0000
@@ -4,54 +4,54 @@
* available at <http://developer.mbed.org/users/hudakz/code/OneWire/>
*
* Example of use:
- *
+ *
* Single sensor.
*
* #include "mbed.h"
* #include "DS1820.h"
- *
+ *
* Serial pc(USBTX, USBRX);
* DigitalOut led(LED1);
* OneWire oneWire(D8); // substitute D8 with actual mbed pin name connected 1-wire bus
* float temp = 0;
* int result = 0;
- *
+ *
* int main()
* {
* pc.printf("\r\n--Starting--\r\n");
* if (ds1820.begin()) {
* while (1) {
* ds1820.startConversion(); // start temperature conversion from analog to digital
- * ThisThread::sleep_for(1000);// let DS1820 complete the temperature conversion
- * result = ds1820.read(temp); // read temperature from DS1820 and perform cyclic redundancy check (CRC)
+ * ThisThread::sleep_for(1000ms);// let DS1820 complete the temperature conversion
+ * result = ds1820.read(temp); // read temperature from DS1820 and perform cyclic redundancy check (CRC)
* switch (result) {
- * case 0: // no errors -> 'temp' contains the value of measured temperature
+ * case 0: // no errors -> 'temp' contains the value of measured temperature
* pc.printf("temp = %3.1f%cC\r\n", temp, 176);
* break;
- *
- * case 1: // no sensor present -> 'temp' is not updated
+ *
+ * case 1: // no sensor present -> 'temp' is not updated
* pc.printf("no sensor present\n\r");
* break;
- *
- * case 2: // CRC error -> 'temp' is not updated
+ *
+ * case 2: // CRC error -> 'temp' is not updated
* pc.printf("CRC error\r\n");
* }
- *
+ *
* led = !led;
* }
* }
* else
* pc.printf("No DS1820 sensor found!\r\n");
* }
- *
- *
+ *
+ *
* More sensors connected to the same 1-wire bus.
- *
+ *
* #include "mbed.h"
* #include "DS1820.h"
- *
+ *
* #define SENSORS_COUNT 64 // number of DS1820 sensors to be connected to the 1-wire bus (max 256)
- *
+ *
* Serial pc(USBTX, USBRX);
* DigitalOut led(LED1);
* OneWire oneWire(D8); // substitute D8 with actual mbed pin name connected to the DS1820 data pin
@@ -59,10 +59,10 @@
* int sensors_found = 0; // counts the actually found DS1820 sensors
* float temp = 0;
* int result = 0;
- *
+ *
* int main() {
* int i = 0;
- *
+ *
* pc.printf("\r\n Starting \r\n");
* //Enumerate (i.e. detect) DS1820 sensors on the 1-wire bus
* for(i = 0; i < SENSORS_COUNT; i++) {
@@ -72,46 +72,61 @@
* break;
* }
* }
- *
+ *
* sensors_found = i;
- *
+ *
* if (sensors_found == 0) {
* pc.printf("No DS1820 sensor found!\r\n");
* return -1;
* }
* else
* pc.printf("Found %d sensors.\r\n", sensors_found);
- *
+ *
* while(1) {
* pc.printf("-------------------\r\n");
* for(i = 0; i < sensors_found; i++)
- * ds1820[i]->startConversion(); // start temperature conversion from analog to digital
- * ThisThread::sleep_for(1000); // let DS1820s complete the temperature conversion
+ * ds1820[i]->startConversion(); // start temperature conversion from analog to digital
+ * ThisThread::sleep_for(1000ms); // let DS1820s complete the temperature conversion
* for(int i = 0; i < sensors_found; i++) {
* if(ds1820[i]->isPresent())
* pc.printf("temp[%d] = %3.1f%cC\r\n", i, ds1820[i]->read(), 176); // read temperature
* }
* }
* }
- *
+ *
*/
-
#include "DS1820.h"
-#define DEBUG 0
+//#define DEBUG 1
//* Initializing static members
-uint8_t DS1820::lastAddr[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+uint8_t DS1820:: _lastAddr[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
+
/**
* @brief Constructs a generic DS1820 sensor
* @note begin() must be called to detect and initialize the actual model
- * @param pin: Name of data pin
+ * @param gpioPin: Name of the GPIO pin
* @retval
*/
-DS1820::DS1820(PinName pin, int sample_point_us /* = 13 */) {
- oneWire = new OneWire(pin, sample_point_us);
- present = false;
- model_s = false;
+DS1820::DS1820(PinName gpioPin, int samplePoint_us /*=13*/ )
+{
+ _oneWire = new OneWire(gpioPin, samplePoint_us);
+ _present = false;
+ _model_s = false;
+}
+
+/**
+ * @brief Constructs a generic DS1820 sensor
+ * @note begin() must be called to detect and initialize the actual model
+ * @param txPin: UART's Tx pin
+ * @param rxPin: UART's Rx pin
+ * @retval
+ */
+DS1820::DS1820(PinName txPin, PinName rxPin)
+{
+ _oneWire = new OneWire(txPin, rxPin);
+ _present = false;
+ _model_s = false;
}
/**
@@ -120,10 +135,11 @@
* @param pin: Name of data pin
* @retval
*/
-DS1820::DS1820(OneWire* wire) :
- oneWire(wire) {
- present = false;
- model_s = false;
+DS1820::DS1820(OneWire* oneWire) :
+ _oneWire(oneWire)
+{
+ _present = false;
+ _model_s = false;
}
/**
@@ -133,73 +149,82 @@
* @retval true: if a DS1820 family sensor was detected and initialized
false: otherwise
*/
-bool DS1820::begin(void) {
+bool DS1820::begin(void)
+{
#if DEBUG
printf("lastAddr =");
- for(uint8_t i = 0; i < 8; i++) {
+ for (uint8_t i = 0; i < 8; i++) {
printf(" %x", lastAddr[i]);
}
+
printf("\r\n");
#endif
- if(!oneWire->search(lastAddr)) {
+ if (!_oneWire->search(_lastAddr))
+ {
#if DEBUG
printf("No addresses.\r\n");
#endif
- oneWire->reset_search();
- ThisThread::sleep_for(250);
+ _oneWire->reset_search();
+#if MBED_MAJOR_VERSION == 2
+ wait_ms(250);
+#else
+ ThisThread::sleep_for(250ms);
+#endif
return false;
}
-
+
for (int i = 0; i < 8; i++)
- addr[i] = lastAddr[i];
+ _addr[i] = _lastAddr[i];
#if DEBUG
printf("ROM =");
- for(uint8_t i = 0; i < 8; i++) {
+ for (uint8_t i = 0; i < 8; i++) {
printf(" %x", addr[i]);
}
+
printf("\r\n");
#endif
-
- if(OneWire::crc8(addr, 7) == addr[7]) {
- present = true;
+ if (OneWire::crc8(_addr, 7) == _addr[7]) {
+ _present = true;
// the first ROM byte indicates which chip
- switch(addr[0]) {
- case 0x10:
- model_s = true;
-#if DEBUG
- printf("DS18S20 or old DS1820\r\n");
-#endif
- break;
+ switch (_addr[0]) {
+ case 0x10:
+ _model_s = true;
+ #if DEBUG
+ printf("DS18S20 or old DS1820\r\n");
+ #endif
+ break;
- case 0x28:
- model_s = false;
-#if DEBUG
- printf("DS18B20\r\n");
-#endif
- break;
+ case 0x28:
+ _model_s = false;
+ #if DEBUG
+ printf("DS18B20\r\n");
+ #endif
+ break;
- case 0x22:
- model_s = false;
-#if DEBUG
- printf("DS1822\r\n");
-#endif
- break;
+ case 0x22:
+ _model_s = false;
+ #if DEBUG
+ printf("DS1822\r\n");
+ #endif
+ break;
- default:
- present = false;
-#if DEBUG
- printf("Device doesn't belong to the DS1820 family\r\n");
-#endif
- return false;
+ default:
+ _present = false;
+ #if DEBUG
+ printf("Device doesn't belong to the DS1820 family\r\n");
+ #endif
+ return false;
}
+
return true;
}
- else {
-#if DEBUG
+ else
+ {
+#if DEBUG
printf("Invalid CRC!\r\n");
-#endif
+#endif
return false;
}
}
@@ -207,14 +232,15 @@
/**
* @brief Informs about presence of a DS1820 sensor.
* @note begin() shall be called before using this function
- * if a generic DS1820 instance was created by the user.
+ * if a generic DS1820 instance was created by the user.
* No need to call begin() for a specific DS1820 instance.
* @param
* @retval true: when a DS1820 sensor is present
* false: otherwise
*/
-bool DS1820::isPresent(void) {
- return present;
+bool DS1820::isPresent(void)
+{
+ return _present;
}
/**
@@ -226,27 +252,29 @@
* @param res: Resolution of the temperature-to-digital conversion in bits.
* @retval
*/
-void DS1820::setResolution(uint8_t res) {
+void DS1820::setResolution(uint8_t res)
+{
// keep resolution within limits
- if(res > 12)
+
+ if (res > 12)
res = 12;
- if(res < 9)
- res = 9;
- if(model_s)
+ if (res < 9)
+ res = 9;
+ if (_model_s)
res = 9;
-
- oneWire->reset();
- oneWire->select(addr);
- oneWire->write_byte(0xBE); // to read Scratchpad
- for(uint8_t i = 0; i < 9; i++) // read Scratchpad bytes
- data[i] = oneWire->read_byte();
+
+ _oneWire->reset();
+ _oneWire->select(_addr);
+ _oneWire->write_byte(0xBE); // to read Scratchpad
+ for (uint8_t i = 0; i < 9; i++) // read Scratchpad bytes
+ _data[i] = _oneWire->read_byte();
- data[4] |= (res - 9) << 5; // update configuration byte (set resolution)
- oneWire->reset();
- oneWire->select(addr);
- oneWire->write_byte(0x4E); // to write into Scratchpad
- for(uint8_t i = 2; i < 5; i++) // write three bytes (2nd, 3rd, 4th) into Scratchpad
- oneWire->write_byte(data[i]);
+ _data[4] |= (res - 9) << 5; // update configuration byte (set resolution)
+ _oneWire->reset();
+ _oneWire->select(_addr);
+ _oneWire->write_byte(0x4E); // to write into Scratchpad
+ for (uint8_t i = 2; i < 5; i++) // write three bytes (2nd, 3rd, 4th) into Scratchpad
+ _oneWire->write_byte(_data[i]);
}
/**
@@ -259,11 +287,12 @@
* @param
* @retval
*/
-void DS1820::startConversion(void) {
- if(present) {
- oneWire->reset();
- oneWire->select(addr);
- oneWire->write_byte(0x44); //start temperature conversion
+void DS1820::startConversion(void)
+{
+ if (_present) {
+ _oneWire->reset();
+ _oneWire->select(_addr);
+ _oneWire->write_byte(0x44); //start temperature conversion
}
}
@@ -273,49 +302,48 @@
* @param
* @retval Floating point temperature value
*/
-float DS1820::read(void) {
- if(present) {
- oneWire->reset();
- oneWire->select(addr);
- oneWire->write_byte(0xBE); // to read Scratchpad
- for(uint8_t i = 0; i < 9; i++) // reading scratchpad registers
- data[i] = oneWire->read_byte();
+float DS1820::read(void)
+{
+ if (_present) {
+ _oneWire->reset();
+ _oneWire->select(_addr);
+ _oneWire->write_byte(0xBE); // to read Scratchpad
+ for (uint8_t i = 0; i < 9; i++) // reading scratchpad registers
+ _data[i] = _oneWire->read_byte();
// Convert the raw bytes to a 16-bit unsigned value
- uint16_t* p_word = reinterpret_cast < uint16_t * > (&data[0]);
+ uint16_t* p_word = reinterpret_cast < uint16_t * > (&_data[0]);
#if DEBUG
printf("raw = %#x\r\n", *p_word);
-#endif
-
- if(model_s) {
+#endif
+ if (_model_s) {
*p_word = *p_word << 3; // 9-bit resolution
- if(data[7] == 0x10) {
+ if (_data[7] == 0x10) {
// "count remain" gives full 12-bit resolution
- *p_word = (*p_word & 0xFFF0) + 12 - data[6];
+ *p_word = (*p_word & 0xFFF0) + 12 - _data[6];
}
}
else {
- uint8_t cfg = (data[4] & 0x60); // default 12-bit resolution
-
+ uint8_t cfg = (_data[4] & 0x60); // default 12-bit resolution
+
// at lower resolution, the low bits are undefined, so let's clear them
- if(cfg == 0x00)
+ if (cfg == 0x00)
*p_word = *p_word &~7; // 9-bit resolution
else
- if(cfg == 0x20)
+ if (cfg == 0x20)
*p_word = *p_word &~3; // 10-bit resolution
else
- if(cfg == 0x40)
+ if (cfg == 0x40)
*p_word = *p_word &~1; // 11-bit resolution
-
}
// Convert the raw bytes to a 16-bit signed fixed point value :
// 1 sign bit, 7 integer bits, 8 fractional bits (two’s compliment
// and the LSB of the 16-bit binary number represents 1/256th of a unit).
*p_word = *p_word << 4;
-
+
// Convert to floating point value
return(toFloat(*p_word));
}
@@ -335,70 +363,72 @@
* 1 - sensor not present ('temp' is not updated)
* 2 - CRC error ('temp' is not updated)
*/
-uint8_t DS1820::read(float& temp) {
- if(present) {
- oneWire->reset();
- oneWire->select(addr);
- oneWire->write_byte(0xBE); // to read Scratchpad
- for(uint8_t i = 0; i < 9; i++) // reading scratchpad registers
- data[i] = oneWire->read_byte();
+uint8_t DS1820::read(float& temp)
+{
+ if (_present) {
+ _oneWire->reset();
+ _oneWire->select(_addr);
+ _oneWire->write_byte(0xBE); // to read Scratchpad
+ for (uint8_t i = 0; i < 9; i++) // reading scratchpad registers
+ _data[i] = _oneWire->read_byte();
- if(oneWire->crc8(data, 8) != data[8]) // if calculated CRC does not match the stored one
+ if (_oneWire->crc8(_data, 8) != _data[8]) // if calculated CRC does not match the stored one
{
#if DEBUG
- for(uint8_t i = 0; i < 9; i++)
+ for (uint8_t i = 0; i < 9; i++)
printf("data[%d]=0x%.2x\r\n", i, data[i]);
-#endif
+#endif
return 2; // return with CRC error
}
// Convert the raw bytes to a 16bit unsigned value
- uint16_t* p_word = reinterpret_cast < uint16_t * > (&data[0]);
+ uint16_t* p_word = reinterpret_cast < uint16_t * > (&_data[0]);
#if DEBUG
printf("raw = %#x\r\n", *p_word);
#endif
-
- if(model_s) {
- *p_word = *p_word << 3; // 9 bit resolution, max conversion time = 750ms
- if(data[7] == 0x10) {
+ if (_model_s) {
+ *p_word = *p_word << 3; // 9 bit resolution, max conversion time = 750ms
+ if (_data[7] == 0x10) {
// "count remain" gives full 12 bit resolution
- *p_word = (*p_word & 0xFFF0) + 12 - data[6];
+ *p_word = (*p_word & 0xFFF0) + 12 - _data[6];
}
// Convert the raw bytes to a 16bit signed fixed point value :
// 1 sign bit, 7 integer bits, 8 fractional bits (two's compliment
// and the LSB of the 16bit binary number represents 1/256th of a unit).
*p_word = *p_word << 4;
+
// Convert to floating point value
temp = toFloat(*p_word);
- return 0; // return with no errors
+ return 0; // return with no errors
}
else {
- uint8_t cfg = (data[4] & 0x60); // default 12bit resolution, max conversion time = 750ms
+ uint8_t cfg = (_data[4] & 0x60); // default 12bit resolution, max conversion time = 750ms
// at lower resolution, the low bits are undefined, so let's clear them
- if(cfg == 0x00)
- *p_word = *p_word &~7; // 9bit resolution, max conversion time = 93.75ms
+ if (cfg == 0x00)
+ *p_word = *p_word &~7; // 9bit resolution, max conversion time = 93.75ms
else
- if(cfg == 0x20)
- *p_word = *p_word &~3; // 10bit resolution, max conversion time = 187.5ms
+ if (cfg == 0x20)
+ *p_word = *p_word &~3; // 10bit resolution, max conversion time = 187.5ms
else
- if(cfg == 0x40)
- *p_word = *p_word &~1; // 11bit resolution, max conversion time = 375ms
+ if (cfg == 0x40)
+ *p_word = *p_word &~1; // 11bit resolution, max conversion time = 375ms
// Convert the raw bytes to a 16bit signed fixed point value :
// 1 sign bit, 7 integer bits, 8 fractional bits (two's complement
// and the LSB of the 16bit binary number represents 1/256th of a unit).
*p_word = *p_word << 4;
+
// Convert to floating point value
temp = toFloat(*p_word);
- return 0; // return with no errors
+ return 0; // return with no errors
}
}
else
- return 1; // error, sensor is not present
+ return 1; // error, sensor is not present
}
/**
@@ -406,14 +436,14 @@
* @note The 16-bit unsigned integer represnts actually
* a 16-bit signed fixed point value:
* 1 sign bit, 7 integer bits, 8 fractional bits (two’s complement
- * and the LSB of the 16-bit binary number represents 1/256th of a unit).
+ * and the LSB of the 16-bit binary number represents 1/256th of a unit).
* @param 16-bit unsigned integer
* @retval Floating point value
*/
-float DS1820::toFloat(uint16_t word) {
- if(word & 0x8000)
- return (-float(uint16_t(~word + 1)) / 256.0f);
+float DS1820::toFloat(uint16_t word)
+{
+ if (word & 0x8000)
+ return(-float(uint16_t(~word + 1)) / 256.0f);
else
- return (float(word) / 256.0f);
+ return(float(word) / 256.0f);
}
-
diff -r 74a4ff420541 -r d683d826dccd DS1820.h
--- a/DS1820.h Mon Jul 20 08:09:58 2020 +0000
+++ b/DS1820.h Mon Dec 28 21:15:27 2020 +0000
@@ -1,7 +1,7 @@
#ifndef DS1820_H_
#define DS1820_H_
- #include <OneWire.h>
+ #include "OneWire.h"
/**
* Dallas' DS1820 family temperature sensor.
@@ -9,20 +9,20 @@
* available at <http://developer.mbed.org/users/hudakz/code/OneWire/>
*
* Example of use:
- *
+ *
* @code
- *
+ *
* Single sensor.
*
* #include "mbed.h"
* #include "DS1820.h"
- *
+ *
* Serial pc(USBTX, USBRX);
* DigitalOut led(LED1);
* DS1820 ds1820(D8); // substitute D8 with actual mbed pin name connected to 1-wire bus
* float temp = 0;
* int result = 0;
- *
+ *
* int main()
* {
* pc.printf("\r\n--Starting--\r\n");
@@ -35,30 +35,30 @@
* case 0: // no errors -> 'temp' contains the value of measured temperature
* pc.printf("temp = %3.1f%cC\r\n", temp, 176);
* break;
- *
+ *
* case 1: // no sensor present -> 'temp' is not updated
* pc.printf("no sensor present\n\r");
* break;
- *
+ *
* case 2: // CRC error -> 'temp' is not updated
* pc.printf("CRC error\r\n");
* }
- *
+ *
* led = !led;
* }
* }
* else
* pc.printf("No DS1820 sensor found!\r\n");
* }
- *
- *
+ *
+ *
* More sensors connected to the same 1-wire bus.
- *
+ *
* #include "mbed.h"
* #include "DS1820.h"
- *
+ *
* #define SENSORS_COUNT 64 // number of DS1820 sensors to be connected to the 1-wire bus (max 256)
- *
+ *
* Serial pc(USBTX, USBRX);
* DigitalOut led(LED1);
* OneWire oneWire(D8); // substitute D8 with actual mbed pin name connected to the DS1820 data pin
@@ -66,10 +66,10 @@
* int sensors_found = 0; // counts the actually found DS1820 sensors
* float temp = 0;
* int result = 0;
- *
+ *
* int main() {
* int i = 0;
- *
+ *
* pc.printf("\r\n Starting \r\n");
* //Enumerate (i.e. detect) DS1820 sensors on the 1-wire bus
* for(i = 0; i < SENSORS_COUNT; i++) {
@@ -79,20 +79,20 @@
* break;
* }
* }
- *
+ *
* sensors_found = i;
- *
+ *
* if (sensors_found == 0) {
* pc.printf("No DS1820 sensor found!\r\n");
* return -1;
* }
* else
* pc.printf("Found %d sensors.\r\n", sensors_found);
- *
+ *
* while(1) {
* pc.printf("-------------------\r\n");
* for(i = 0; i < sensors_found; i++)
- * ds1820[i]->startConversion(); // start temperature conversion from analog to digital
+ * ds1820[i]->startConversion(); // start temperature conversion from analog to digital
* wait(1.0); // let DS1820s complete the temperature conversion
* for(int i = 0; i < sensors_found; i++) {
* if(ds1820[i]->isPresent())
@@ -100,32 +100,34 @@
* }
* }
* }
- *
+ *
* @endcode
- *
- * Note: Don't forget to connect a 4.7k Ohm resistor
+ *
+ * Note: Don't forget to connect a 4.7k Ohm resistor
* between the DS1820's data pin and the +3.3V pin
*
*/
class DS1820
{
- OneWire *oneWire;
- bool present;
- bool model_s;
- uint8_t data[12];
- uint8_t addr[8];
+ OneWire* _oneWire;
+ bool _present;
+ bool _model_s;
+ uint8_t _data[12];
+ uint8_t _addr[8];
+ static uint8_t _lastAddr[8];
+
float toFloat(uint16_t word);
- static uint8_t lastAddr[8];
-
+
public:
- DS1820(PinName pin, int sample_point_us = 13);
-// DS1820(char model, PinName pin);
- DS1820(OneWire* wire);
- bool begin(void);
- bool isPresent();
- void setResolution(uint8_t res);
- void startConversion(void);
- float read(void);
+ DS1820(PinName gpioPin, int samplePoint_us = 13);
+ DS1820(PinName txPin, PinName rxPin);
+ DS1820(OneWire* oneWire);
+
+ bool begin(void);
+ bool isPresent();
+ void setResolution(uint8_t res);
+ void startConversion(void);
+ float read(void);
uint8_t read(float& temp);
};
#endif /* DS1820_H_ */
diff -r 74a4ff420541 -r d683d826dccd OneWire.lib --- a/OneWire.lib Mon Jul 20 08:09:58 2020 +0000 +++ b/OneWire.lib Mon Dec 28 21:15:27 2020 +0000 @@ -1,1 +1,1 @@ -http://developer.mbed.org/users/hudakz/code/OneWire/#7f7759008807 +http://developer.mbed.org/users/hudakz/code/OneWire/#4c3edd30ad6e