alessio zaino
Team Diana
Diff: DS1820.cpp
- Revision:
- 20:98c261bcb399
- Parent:
- 17:9ff584b9809f
- Child:
- 22:44b91be5b3f6
--- a/DS1820.cpp Sun Jan 27 18:02:01 2019 +0000
+++ b/DS1820.cpp Sun Mar 10 13:19:03 2019 +0000
@@ -5,34 +5,114 @@
*
* Example of use:
*
- * #include "DS1820.h"
+ * Single sensor.
*
- * Serial serial(USBTX, USBRX);
+ * #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
+ * wait(1.0); // 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
+ * 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
+ * DS1820* ds1820[SENSORS_COUNT];
+ * int sensors_found = 0; // counts the actually found DS1820 sensors
+ * float temp = 0;
+ * int result = 0;
*
* int main() {
- * DS1820 ds1820(PA_9); // substitute PA_9 with actual mbed pin name connected to the DS1820 data pin
- *
- * if(ds1820.begin()) {
- * ds1820.startConversion();
- * wait(1.0);
- * while(1) {
- * printf("temp = %3.1f\r\n", ds1820.read()); // read temperature
- * ds1820.startConversion(); // start temperature conversion
- * wait(1.0); // let DS1820 complete the temperature conversion
- * }
- * } else
- * printf("No DS1820 sensor found!\r\n");
+ * 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++) {
+ * ds1820[i] = new DS1820(&oneWire);
+ * if(!ds1820[i]->begin()) {
+ * delete ds1820[i];
+ * 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
+ * wait(1.0); // 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
+ * }
+ * }
* }
- *
*
- * Note: Don't forget to connect a 4.7k Ohm resistor
- * between the DS1820's data pin and the +3.3V pin
- *
*/
#include "DS1820.h"
-//#define DEBUG 1
+#define DEBUG 0
+
+//* Initializing static members
+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
+ * @retval
+ */
+DS1820::DS1820(PinName pin) {
+ oneWire = new OneWire(pin);
+ present = false;
+ model_s = false;
+}
/**
* @brief Constructs a generic DS1820 sensor
@@ -40,34 +120,13 @@
* @param pin: Name of data pin
* @retval
*/
-DS1820::DS1820(PinName pin) :
- oneWire(pin) {
+DS1820::DS1820(OneWire* wire) :
+ oneWire(wire) {
present = false;
model_s = false;
}
/**
- * @brief Constructs a specific model
- * @note No need to call begin() to detect and initialize the model
- * @param model: One character model name: 'S', 's', 'B' or 'b'
- * pin: Name of data pin
- * @retval
- */
-DS1820::DS1820(char model, PinName pin) :
- oneWire(pin) {
- if((model == 'S') or (model == 's')) {
- present = true;
- model_s = true;
- }
- else if((model == 'B') or (model == 'b')) {
- present = true;
- model_s = false;
- }
- else
- present = false;
-}
-
-/**
* @brief Detects and initializes the actual DS1820 model
* @note
* @param
@@ -75,16 +134,24 @@
false: otherwise
*/
bool DS1820::begin(void) {
- oneWire.reset_search();
- wait_ms(250);
- if(!oneWire.search(addr)) {
+#if DEBUG
+ printf("lastAddr =");
+ for(uint8_t i = 0; i < 8; i++) {
+ printf(" %x", lastAddr[i]);
+ }
+ printf("\r\n");
+#endif
+ if(!oneWire->search(lastAddr)) {
#if DEBUG
printf("No addresses.\r\n");
#endif
- oneWire.reset_search();
+ oneWire->reset_search();
wait_ms(250);
return false;
}
+
+ for (int i = 0; i < 8; i++)
+ addr[i] = lastAddr[i];
#if DEBUG
printf("ROM =");
@@ -168,18 +235,18 @@
if(model_s)
res = 9;
- oneWire.reset();
- oneWire.skip();
- oneWire.write_byte(0xBE); // to read Scratchpad
+ 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[i] = oneWire->read_byte();
data[4] |= (res - 9) << 5; // update configuration byte (set resolution)
- oneWire.reset();
- oneWire.skip();
- oneWire.write_byte(0x4E); // to write into Scratchpad
+ 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]);
+ oneWire->write_byte(data[i]);
}
/**
@@ -194,9 +261,9 @@
*/
void DS1820::startConversion(void) {
if(present) {
- oneWire.reset();
- oneWire.skip();
- oneWire.write_byte(0x44); //start temperature conversion
+ oneWire->reset();
+ oneWire->select(addr);
+ oneWire->write_byte(0x44); //start temperature conversion
}
}
@@ -208,11 +275,11 @@
*/
float DS1820::read(void) {
if(present) {
- oneWire.reset();
- oneWire.skip();
- oneWire.write_byte(0xBE); // to read Scratchpad
+ 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();
+ 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]);
@@ -270,13 +337,13 @@
*/
uint8_t DS1820::read(float& temp) {
if(present) {
- oneWire.reset();
- oneWire.skip();
- oneWire.write_byte(0xBE); // to read Scratchpad
+ 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();
+ 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++)