Revision 5:6226f3c566ef, committed 2016-05-11

Comitter:

andrewboyson

Date:

Wed May 11 16:42:35 2016 +0000

Parent:

4:e076884ef8bd

Child:

6:be97d38e0b01

Commit message:

Added CRC to 1-wire

Changed in this revision

--- a/1-wire.cpp	Tue May 03 09:23:26 2016 +0000
+++ b/1-wire.cpp	Wed May 11 16:42:35 2016 +0000
@@ -10,69 +10,69 @@
 static int busvalue;
 
 //Delays
-#define           ATTACH_DELAY    7
-#define          INITIAL_DELAY  100
-#define    RESET_BUS_LOW_DELAY  480
-#define    READ_PRESENCE_DELAY   70
-#define    RESET_RELEASE_DELAY  410
-#define  WRITE_0_BUS_LOW_DELAY   60
-#define  WRITE_0_RELEASE_DELAY   10
-#define  WRITE_1_BUS_LOW_DELAY    6
-#define  WRITE_1_RELEASE_DELAY   64
-#define READ_BIT_BUS_LOW_DELAY    6
-#define         READ_BIT_DELAY    9
-#define READ_BIT_RELEASE_DELAY   55
-#define         BUS_TIMEOUT_MS 1000
+#define           ATTACH_US    7
+#define          INITIAL_US  100
+#define    RESET_BUS_LOW_US  480
+#define    READ_PRESENCE_US   70
+#define    RESET_RELEASE_US  410
+#define  WRITE_0_BUS_LOW_US   60
+#define  WRITE_0_RELEASE_US   10
+#define  WRITE_1_BUS_LOW_US    6
+#define  WRITE_1_RELEASE_US   64
+#define READ_BIT_BUS_LOW_US    6
+#define         READ_BIT_US    9
+#define READ_BIT_RELEASE_US   55
+#define      BUS_TIMEOUT_MS 1000
 
 static int busbusy = false;   //Set whenever an operation starts; reset by finishbus interrupt;
 static Timer busbusytimer;
 
-static void         buslow (void) {        pin = 0;   pin.output();                  }
 static Timeout startbuslow;
-static void         busfree(void) {                   pin.input ();                  }
 static Timeout startbusfree;
-static void         bushigh(void) {        pin = 1;   pin.output();                  }
 static Timeout startbushigh;
-static void         busread(void) {   busvalue = pin;                                }
 static Timeout startbusread;
-static void         busidle(void) {                   pin.input (); busbusy = false; }
 static Timeout startbusidle;
+static void         buslow (void) { pin.output(); pin = 0;                         }
+static void         busfree(void) { pin.input ();                                  }
+static void         bushigh(void) { pin.output(); pin = 1;                         }
+static void         busread(void) {               busvalue = pin;                  }
+static void         busidle(void) { pin.input ();                 busbusy = false; }
 
 static void reset()
 {
     busbusy = true;
-    int delay =    INITIAL_DELAY - ATTACH_DELAY; startbuslow.attach_us(&buslow,   delay);
-    delay += RESET_BUS_LOW_DELAY - ATTACH_DELAY; startbusfree.attach_us(&busfree, delay);
-    delay += READ_PRESENCE_DELAY - ATTACH_DELAY; startbusread.attach_us(&busread, delay);
-    delay += RESET_RELEASE_DELAY - ATTACH_DELAY; startbusidle.attach_us(&busidle, delay);
+    int start =    INITIAL_US - ATTACH_US; startbuslow .attach_us(&buslow,  start);
+    start += RESET_BUS_LOW_US - ATTACH_US; startbusfree.attach_us(&busfree, start);
+    start += READ_PRESENCE_US - ATTACH_US; startbusread.attach_us(&busread, start);
+    start += RESET_RELEASE_US - ATTACH_US; startbusidle.attach_us(&busidle, start);
 }
 static void writebit(int bit, int msToPullUp)
 {
     busbusy = true;
-    int delay = INITIAL_DELAY - ATTACH_DELAY;
-    startbuslow.attach_us(&buslow, delay);
-    delay += bit ? WRITE_1_BUS_LOW_DELAY : WRITE_0_BUS_LOW_DELAY;
-    delay -= ATTACH_DELAY;
+    int start = INITIAL_US - ATTACH_US;
+    startbuslow.attach_us(&buslow, start);
+    start += bit ? WRITE_1_BUS_LOW_US : WRITE_0_BUS_LOW_US;
+    start -= ATTACH_US;
     if (msToPullUp)
     {
-        startbushigh.attach_us(&bushigh, delay);
-        delay += msToPullUp * 1000 - ATTACH_DELAY;
+        startbushigh.attach_us(&bushigh, start);
+        start += msToPullUp * 1000 - ATTACH_US;
     }
     else
     {
-        startbusfree.attach_us(&busfree, delay);
-        delay += bit ? WRITE_1_RELEASE_DELAY : WRITE_0_RELEASE_DELAY;
-        delay -= ATTACH_DELAY;
+        startbusfree.attach_us(&busfree, start);
+        start += bit ? WRITE_1_RELEASE_US : WRITE_0_RELEASE_US;
+        start -= ATTACH_US;
     }
-    startbusidle.attach_us(&busidle,  delay);
+    startbusidle.attach_us(&busidle,  start);
 }
 static void initiatebitread()
 {
     busbusy = true;
-    int delay =       INITIAL_DELAY - ATTACH_DELAY; startbuslow.attach_us(&buslow,   delay);
-    delay += READ_BIT_BUS_LOW_DELAY - ATTACH_DELAY; startbusfree.attach_us(&busfree, delay);
-    delay +=         READ_BIT_DELAY - ATTACH_DELAY; startbusread.attach_us(&busread, delay);
-    delay += READ_BIT_RELEASE_DELAY - ATTACH_DELAY; startbusidle.attach_us(&busidle, delay);
+    int start =       INITIAL_US - ATTACH_US; startbuslow .attach_us(&buslow,  start);
+    start += READ_BIT_BUS_LOW_US - ATTACH_US; startbusfree.attach_us(&busfree, start);
+    start +=         READ_BIT_US - ATTACH_US; startbusread.attach_us(&busread, start);
+    start += READ_BIT_RELEASE_US - ATTACH_US; startbusidle.attach_us(&busidle, start);
 }
 
 //Exchange zone
@@ -90,6 +90,23 @@
 static char*  precv = NULL;
 static int pullupms = 0;
 
+static char crc;
+static void resetCrc()
+{
+    crc = 0;
+}
+static void addBitToCrc(int bit)
+{
+    //Logical Exclusive Or of the 9th output of the shift register with the input
+    int feedback = !(crc & 0x80) != !bit;
+    
+    //Move the shift register one place to the left leaving a zero in the lsb
+    crc <<= 1;
+    
+    //Exclusive Or the shift register with polynomial X5 + X4 + 1
+    if (feedback) crc ^= 0x31;
+}
+
 static void resetBitPosition(int* pByteIndex, char* pBitMask)
 {
     *pBitMask = 1;
@@ -148,6 +165,10 @@
     xchgstate = XCHG_RESET;
     reset();
 }
+char OneWireCrc()
+{
+    return crc;
+}
 int OneWireMain()
 {
     static int byteindex;
@@ -198,6 +219,7 @@
                 resetBitPosition(&byteindex, &bitmask);
                 if (moreBitsToRead(byteindex))
                 {
+                    resetCrc();
                     initiatebitread();
                     xchgstate = XCHG_READ;
                     
@@ -209,6 +231,7 @@
             }
             break;
         case XCHG_READ:
+            addBitToCrc(busvalue);
             setBitAtPosition(byteindex, bitmask, busvalue);
             incrementBitPosition(&byteindex, &bitmask);
             if (moreBitsToRead(byteindex))

--- a/1-wire.h	Tue May 03 09:23:26 2016 +0000
+++ b/1-wire.h	Wed May 11 16:42:35 2016 +0000
@@ -1,4 +1,5 @@
 extern int  OneWireInit();
 extern int  OneWireBusy();
 extern void OneWireExchange(int lenBytesToSend, int lenBytesToRecv, char *pBytesToSend, char *pBytesToRecv, int msToPullUp);
+extern char OneWireCrc();
 extern int  OneWireMain();

--- a/ds18b20.cpp	Tue May 03 09:23:26 2016 +0000
+++ b/ds18b20.cpp	Wed May 11 16:42:35 2016 +0000
@@ -12,6 +12,8 @@
 static int sendlen = 0;
 static int recvlen = 0;
 
+uint16_t DS18B20Value;
+
 void DS18B20ReadRom()
 {
     sendlen = 1;
@@ -20,11 +22,12 @@
     OneWireExchange(sendlen, recvlen, send, recv, 0);
 }
 void DS18B20ReadScratchpad()
-{
+{   
     sendlen = 2;
     send[0] = 0xCC;
     send[1] = 0xBE;
     recvlen = 9;
+    for (int i = 0; i < recvlen; i++) recv[i] = 0;
     OneWireExchange(sendlen, recvlen, send, recv, 0);
 }
 void DS18B20ConvertT()
@@ -33,17 +36,52 @@
     send[0] = 0xCC;
     send[1] = 0x44;
     recvlen = 0;
+    for (int i = 0; i < recvlen; i++) recv[i] = 0;
     OneWireExchange(sendlen, recvlen, send, recv, 750);
 }
-int DS18B20Init()
+#define IDLE                0
+#define CONVERT_T           1
+#define READ_SCRATCH_PAD    2
+#define EXTRACT_TEMPERATURE 3
+static int state = IDLE;
+static int handlestate()
 {
-    ticker.attach(&DS18B20ReadScratchpad, 10.0);
+    if (OneWireBusy()) return 0;
+    
+    switch (state)
+    {
+        case IDLE:
+            break;
+        case CONVERT_T:
+            DS18B20ConvertT();
+            state = READ_SCRATCH_PAD;
+            break;
+        case READ_SCRATCH_PAD:
+            DS18B20ReadScratchpad();
+            state = EXTRACT_TEMPERATURE;
+            break;
+        case EXTRACT_TEMPERATURE:
+            if (OneWireCrc())
+            {
+                DS18B20Value = 0xFFFF;
+            }
+            else
+            {
+                DS18B20Value = recv[1];
+                DS18B20Value <<= 8;
+                DS18B20Value |= recv[0];
+            }
+            state = IDLE;
+            break;
+        default:
+            LogF("Unknown DS18B20 state %d\r\n", state);
+            return -1;
+    }
     return 0;
 }
-int DS18B20Main()
+static void logcomms()
 {
     static int wasbusy = false;
-
     if (!OneWireBusy() && wasbusy)
     {
         LogF("1-wire | send:");
@@ -52,7 +90,24 @@
         for (int i = 0; i < recvlen; i++) LogF(" %02x", recv[i]);
         LogF("\r\n");
     }
-
     wasbusy = OneWireBusy();
+}
+static void timed()
+{
+    state = CONVERT_T;
+}
+int DS18B20Init()
+{
+    ticker.attach(&timed, 10.0);
+    return 0;
+}
+int DS18B20Main()
+{
+    logcomms();
+    
+    int r = handlestate();
+    
+    if (r) return -1;
+    
     return 0;
 }
\ No newline at end of file

--- a/ds18b20.h	Tue May 03 09:23:26 2016 +0000
+++ b/ds18b20.h	Wed May 11 16:42:35 2016 +0000
@@ -1,2 +1,4 @@
-extern int DS18B20Init();
-extern int DS18B20Main();
\ No newline at end of file
+extern uint16_t DS18B20Value;
+
+extern  int     DS18B20Init();
+extern  int     DS18B20Main();
\ No newline at end of file

--- a/server.cpp	Tue May 03 09:23:26 2016 +0000
+++ b/server.cpp	Wed May 11 16:42:35 2016 +0000
@@ -1,9 +1,10 @@
-#include  "esp.h"
-#include   "at.h"
-#include   "io.h"
-#include  "log.h"
-#include "time.h"
-#include "wifi.h"
+#include     "esp.h"
+#include      "at.h"
+#include      "io.h"
+#include     "log.h"
+#include    "time.h"
+#include    "wifi.h"
+#include "ds18b20.h"
 #define RECV_BUFFER_SIZE 1024
 #define SEND_BUFFER_SIZE  256
 #define SERVER_PORT 80
@@ -33,6 +34,26 @@
     }
     return 0;
 }
+static int addChunkF(int prevlen, char *fmt, ...)
+{
+    //Set up variable arguments
+    va_list argptr;
+    va_start(argptr, fmt);
+        
+    //Fill the buffer
+    int room = SEND_BUFFER_SIZE - prevlen;
+    int sent = vsnprintf(sendbuffer + prevlen, room, fmt, argptr);
+    if (sent > room) sent = room;
+    if (sent < 0) sent = 0;
+    
+    //Finish with variable arguments
+    va_end(argptr);
+    
+    //Return length
+    int len = prevlen + sent;
+    return len < SEND_BUFFER_SIZE ? len : SEND_BUFFER_SIZE;
+    
+}
 
 static int addChunk(int prevlen, char *text)
 {
@@ -125,9 +146,9 @@
             lineToSendToId[id] += 1;
             break;
         case 2:
-            len = fillChunk("Version: ");
-            len = addChunk(len, AtEspVersion);
-            len = addChunk(len, "\r\n");
+            len = 0;
+            len = addChunkF(len, "Version: %s<br/>\r\n", AtEspVersion);
+            len = addChunkF(len, "Temperature: %1.1f\r\n", DS18B20Value / 16.0);
             lineToSendToId[id] += 1;
             break;
         case 3: