Library for reading temperature from DS1820, DS18B20 and DS1822

Dependencies:   LinkedList

Dependents:   heatmap BLE_Temperature BLE_Temperature_Exercise F334andDS18B20 ... more

Fork of DS1820 by David Pairman

HelloWorld: http://mbed.org/users/Sissors/code/DS1820_HelloWorld/

Library should currently work on all mbed targets, let me know if there is an issue. First however make sure you have latest version of mbed library and this library.

Files at this revision

API Documentation at this revision

Comitter:
Sissors
Date:
Sat Mar 11 20:35:59 2017 +0000
Parent:
14:c591209285e9
Commit message:
Removed specialized STM code (still uses OpenDrain mode), should work now still.
;
; Added NRF51822 support by adding a software delay function.

Changed in this revision

DS1820.cpp Show annotated file Show diff for this revision Revisions of this file
diff -r c591209285e9 -r 236eb8f8e73a DS1820.cpp
--- a/DS1820.cpp	Sun Jan 08 17:26:21 2017 +0000
+++ b/DS1820.cpp	Sat Mar 11 20:35:59 2017 +0000
@@ -1,56 +1,38 @@
 #include "DS1820.h"
 
 #ifdef TARGET_STM
-//STM targets use opendrain mode since their GPIO code is too bad to be used like the others
+//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)
-    
-    // TEMP, remove once STM fixed their stuff
-// Enable GPIO clock and return GPIO base address 
-static uint32_t Set_GPIO_Clock(uint32_t port_idx) { 
-    uint32_t gpio_add = 0; 
-    switch (port_idx) { 
-        case PortA: 
-           gpio_add = GPIOA_BASE; 
-           __GPIOA_CLK_ENABLE(); 
-           break; 
-        case PortB: 
-            gpio_add = GPIOB_BASE; 
-            __GPIOB_CLK_ENABLE(); 
-            break; 
-#if defined(GPIOC_BASE) 
-        case PortC: 
-            gpio_add = GPIOC_BASE; 
-            __GPIOC_CLK_ENABLE(); 
-            break; 
-#endif 
-#if defined(GPIOD_BASE) 
-       case PortD: 
-           gpio_add = GPIOD_BASE; 
-            __GPIOD_CLK_ENABLE(); 
-            break; 
-#endif 
-#if defined(GPIOF_BASE) 
-        case PortF: 
-            gpio_add = GPIOF_BASE; 
-            __GPIOF_CLK_ENABLE(); 
-            break; 
-#endif 
-      default: 
-           error("Pinmap error: wrong port number."); 
-           break; 
-   } 
-   return gpio_add; 
-} 
-
-
 #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
+
 LinkedList<node> DS1820::probes;
  
  
@@ -64,18 +46,7 @@
         RAM[byte_counter] = 0x00;
     
     ONEWIRE_INIT((&_datapin));
-    // Temp code since the above doesn't actually do anything in mbed revisions up to 133
-    #ifdef TARGET_STM
-    
-    uint32_t port_index = STM_PORT(data_pin); 
-    uint32_t pin_index  = STM_PIN(data_pin); 
-    
-    // Enable GPIO clock 
-    uint32_t gpio_add = Set_GPIO_Clock(port_index); 
-    GPIO_TypeDef *gpio = (GPIO_TypeDef *)gpio_add; 
-
-    gpio->OTYPER |= (uint32_t)(1 << pin_index); 
-    #endif
+    INIT_DELAY;
     
     if (!unassignedProbe(&_datapin, _ROM))
         error("No unassigned DS1820 found!\n");
@@ -102,26 +73,26 @@
     bool presence=false;
     ONEWIRE_OUTPUT(pin);
     pin->write(0);          // bring low for 500 us
-    wait_us(500);
+    ONEWIRE_DELAY_US(500);
     ONEWIRE_INPUT(pin);       // let the data line float high
-    wait_us(90);            // wait 90us
+    ONEWIRE_DELAY_US(90);            // wait 90us
     if (pin->read()==0) // see if any devices are pulling the data line low
         presence=true;
-    wait_us(410);
+    ONEWIRE_DELAY_US(410);
     return presence;
 }
  
 void DS1820::onewire_bit_out (DigitalInOut *pin, bool bit_data) {
     ONEWIRE_OUTPUT(pin);
     pin->write(0);
-    wait_us(3);                 // DXP modified from 5
+    ONEWIRE_DELAY_US(3);                 // DXP modified from 5
     if (bit_data) {
         pin->write(1); // bring data line high
-        wait_us(55);
+        ONEWIRE_DELAY_US(55);
     } else {
-        wait_us(55);            // keep data line low
+        ONEWIRE_DELAY_US(55);            // keep data line low
         pin->write(1);
-        wait_us(10);            // DXP added to allow bus to float high before next bit_out
+        ONEWIRE_DELAY_US(10);            // DXP added to allow bus to float high before next bit_out
     }
 }
  
@@ -137,11 +108,11 @@
     bool answer;
     ONEWIRE_OUTPUT(pin);
     pin->write(0);
-    wait_us(3);                 // DXP modofied from 5
+    ONEWIRE_DELAY_US(3);                 // DXP modofied from 5
     ONEWIRE_INPUT(pin);
-    wait_us(10);                // DXP modified from 5
+    ONEWIRE_DELAY_US(10);                // DXP modified from 5
     answer = pin->read();
-    wait_us(45);                // DXP modified from 50
+    ONEWIRE_DELAY_US(45);                // DXP modified from 50
     return answer;
 }
  
@@ -159,18 +130,7 @@
 bool DS1820::unassignedProbe(PinName pin) {
     DigitalInOut _pin(pin);
     ONEWIRE_INIT((&_pin));
-    // Temp code since the above doesn't actually do anything in mbed revisions up to 133
-    #ifdef TARGET_STM
-    
-    uint32_t port_index = STM_PORT(pin); 
-    uint32_t pin_index  = STM_PIN(pin); 
-    
-    // Enable GPIO clock 
-    uint32_t gpio_add = Set_GPIO_Clock(port_index); 
-    GPIO_TypeDef *gpio = (GPIO_TypeDef *)gpio_add; 
-
-    gpio->OTYPER |= (uint32_t)(1 << pin_index); 
-    #endif
+    INIT_DELAY;
     char ROM_address[8];
     return search_ROM_routine(&_pin, 0xF0, ROM_address);
 }