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changeset 10:eb1faf51968e

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- Add some useful return values to search functions. - Remove some unecessary trailing \'s in macros - Replace some inline assembly I missed last time with C/macros.
author darius
date Mon, 12 Jul 2004 23:59:00 +0930
parents 7ed10c59ba06
children ccc39c9f320b
files 1wire-delay.h 1wire.c 1wire.h testavr.c
diffstat 4 files changed, 75 insertions(+), 103 deletions(-) [+]
line wrap: on
line diff
--- a/1wire-delay.h	Mon Jul 12 17:51:20 2004 +0930
+++ b/1wire-delay.h	Mon Jul 12 23:59:00 2004 +0930
@@ -41,7 +41,7 @@
 	"L_%=: nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 
 /* 64 usec */
 #define DELAY_B asm volatile(	\
@@ -53,7 +53,7 @@
 	"nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 
 /* 60 usec */
 #define DELAY_C asm volatile(	\
@@ -65,7 +65,7 @@
 	"nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 
 /* 10 usec */
 #define DELAY_D asm volatile(	\
@@ -73,7 +73,7 @@
 	"L_%=: nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 
 /* 9 usec */
 #define DELAY_E asm volatile(	\
@@ -81,7 +81,7 @@
 	"L_%=: nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 
 /* 55 usec */
 #define DELAY_F asm volatile(	\
@@ -101,7 +101,7 @@
 	"nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 
 /* 0 usec */    
 #define DELAY_G
@@ -124,7 +124,7 @@
 	"nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 
 /* 70 usec */    
 #define DELAY_I asm volatile(	\
@@ -136,7 +136,7 @@
 	"nop\n\t"		\
 	"dec r21\n\t"		\
 	"brne L_%=\n\t"		\
-	::: "r21");
+	::: "r21")
 #else
 #error No 1 wire delay routines for selected clock speed
 #endif
--- a/1wire.c	Mon Jul 12 17:51:20 2004 +0930
+++ b/1wire.c	Mon Jul 12 23:59:00 2004 +0930
@@ -47,25 +47,7 @@
 
 static void
 OWdelay(void) {
-      asm volatile (
-	  "ldi r21, 50\n\t"
-	  "_OWdelay:\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "nop\n\t"
-	  "dec r21\n\t"
-	  "brne _OWdelay\n\t"
-	  ::: "r21");
+    DELAY_I;
 }
 
 /*-----------------------------------------------------------------------------
@@ -75,62 +57,14 @@
  */
 int
 OWTouchReset(void) {
-    uint8_t	result;
+    DELAY_G;
+    OWIREOUTPORT &= ~(_BV(OWIREOUTPIN));
+    OWIREDDR |= _BV(OWIREOUTPIN);
+    DELAY_H;
+    OWIREDDR &= ~(_BV(OWIREOUTPIN));
+    DELAY_I;
 
-    asm volatile (
-	/* Delay G (0 usec) */
-	"\n\t"
-	/* Drive bus low */
-	"cbi %[out], %[opin]\n\t"
-	"sbi %[ddr], %[opin]\n\t"
-	/* Delay H (480 usec) */
-	"ldi r21, 120\n\t"
-	"loopH:\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"dec r21\n\t"
-	"brne loopH\n\t"
-	/* Release bus */
-	"cbi %[ddr], %[opin]\n\t"
-	/* Delay I (70 usec) */
-	"ldi r21, 35\n\t"
-	"loopI:\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"nop\n\t"
-	"dec r21\n\t"
-	"brne loopI\n\t"
-	/* Sample for presense */
-	"ldi %[result], 0\n\t"
-	"sbi %[ddr], 1\n\t"
-	"sbi %[out], 1\n\t"
-	/* 1 == no presence */
-	"sbic %[in], %[ipin]\n\t"
-	"ldi %[result], 1\n\t"
-	"cbi %[out], 1\n\t"
-
-	: [result] "=r" (result)			/* Outputs */
-	: [out]  "I" (_SFR_IO_ADDR(OWIREOUTPORT)),	/* Inputs */
-	  [ddr]  "I" (_SFR_IO_ADDR(OWIREDDR)),
-	  [opin] "I" (OWIREOUTPIN),
-	  [in]   "I" (_SFR_IO_ADDR(OWIREINPORT)),
-	  [ipin] "I" (OWIREINPIN)
-	: "r21");				/* Clobbers */
-
-    return(result);
+    return(OWIREINPORT & _BV(OWIREINPIN) ? 1 : 0);
 }
 
 /*-----------------------------------------------------------------------------
@@ -257,7 +191,12 @@
 /*-----------------------------------------------------------------------------
  * Search algorithm from App note 187 (and 162)
  *
- * Returns 1 when something is found, 0 if nothing present
+ * OWFirst/OWNext return..
+ *         1 when something is found,
+ *         0 no more modules
+ *	   -1 if no presense pulse,
+ *         -2 if bad CRC,
+ *         -3 if bad wiring.
  */
 int
 OWFirst(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) {
@@ -274,9 +213,9 @@
 int
 OWNext(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) {
     uint8_t	bit_test, search_direction, bit_number;
-    uint8_t	last_zero, rom_byte_number, next_result;
-    uint8_t	rom_byte_mask;
+    uint8_t	last_zero, rom_byte_number, rom_byte_mask;
     uint8_t	lastcrc8, crcaccum;
+    int		next_result;
     char	errstr[30];
 
     /* Init for search */
@@ -284,7 +223,7 @@
    last_zero = 0;
    rom_byte_number = 0;
    rom_byte_mask = 1;
-   next_result = 0;
+   next_result = OW_NOMODULES;
    lastcrc8 = 0;
    crcaccum = 0;
 
@@ -304,7 +243,7 @@
 #if OW_DEBUG
 	     uart_putsP(PSTR("No devices on bus\n\r"));
 #endif
-	     return 0;
+	     return OW_NOPRESENCE;
          }
        }
 
@@ -332,9 +271,11 @@
 
 	  /* check for no devices on 1-wire */
 	  if (bit_test == 3) {
+#if OW_DEBUG
 	      sprintf_P(errstr, PSTR("bit_test = %d\n\r"), bit_test);
 	      uart_puts(errstr);
-	      break;
+#endif
+	      return(OW_BADWIRE);
 	  }
 	  else {
 	      /* all devices coupled have 0 or 1 */
@@ -391,7 +332,7 @@
 	  if (lastcrc8) {
 	      sprintf_P(errstr, PSTR("Bad CRC (%d)\n\r"), lastcrc8);
 	      uart_puts(errstr);
-	      next_result = 0;
+	      next_result = OW_BADCRC;
 	  } else {
 	      /*  search successful so set LastDiscrepancy,LastDevice,next_result */
 	      OW_LastDiscrepancy = last_zero;
@@ -400,20 +341,22 @@
 	      sprintf_P(errstr, PSTR("Last device = %d\n\r"), OW_LastDevice);
 	      uart_puts(errstr);
 #endif
-	      next_result = 1;
+	      next_result = OW_FOUND;
 	  }
       }
    }
 
    /* if no device found then reset counters so next 'next' will be
     * like a first */
-   if (!next_result || !ROM[0]) {
+   if (next_result != OW_FOUND || ROM[0] == 0) {
        OW_LastDiscrepancy = 0;
        OW_LastDevice = 0;
        OW_LastFamilyDiscrepancy = 0;
-       next_result = 0;
    }
 
+   if (next_result == OW_FOUND && ROM[0] == 0x00)
+       next_result = OW_BADWIRE;
+   
    return next_result;
 
 }
--- a/1wire.h	Mon Jul 12 17:51:20 2004 +0930
+++ b/1wire.h	Mon Jul 12 23:59:00 2004 +0930
@@ -47,6 +47,13 @@
 #define OWIREDDR		DDRC
 #define OWIREINPIN		OWIREOUTPIN
 
+/* Return codes for OWFirst()/OWNext() */
+#define OW_BADWIRE		-3
+#define OW_BADCRC		-2
+#define OW_NOPRESENCE		-1
+#define OW_NOMODULES		0
+#define OW_FOUND		1
+
 /* General 1 wire commands */
 #define OW_OVRDRV_SKIP_CMD	0x3c
 #define OW_SEARCH_ALRM_CMD	0xec
--- a/testavr.c	Mon Jul 12 17:51:20 2004 +0930
+++ b/testavr.c	Mon Jul 12 23:59:00 2004 +0930
@@ -174,9 +174,9 @@
 	    uart_putsP(PSTR("Resetting... "));
 	    
 	    if (OWTouchReset() == 1)
-		uart_putsP(PSTR("No presense\n\r"));
+		uart_putsP(PSTR("No presense pulse found\n\r"));
 	    else
-		uart_putsP(PSTR("Presense\n\r"));
+		uart_putsP(PSTR("Presense pulse found\n\r"));
 	} else if (cmdbuf[0] == 'r' && cmdbuf[1] == 'e') {
 	    if (OWReadBit())
 		uart_putsP(PSTR("Read a 1\n\r"));
@@ -291,15 +291,34 @@
 	    uart_puts(cmdbuf);
 	} else if (cmdbuf[0] == 's' && cmdbuf[1] == 'r') {
 	    memset(ROM, 0, 8);
-	    if (OWTouchReset()) {
-		uart_putsP(PSTR("No devices on bus\n\r"));
-		break;
-	    }
-	    if (OWFirst(ROM, 1, 0) == 0) {
-		uart_putsP(PSTR("No module found\n\r"));
-		break;
-	    }
+
+	    i = OWFirst(ROM, 1, 0);
 	    do {
+		switch (i) {
+		case OW_BADWIRE:
+		    uart_putsP(PSTR("Presense pulse, but no module found, bad module/cabling?\n\r"));
+		    break;
+
+		case OW_NOPRESENCE:
+		    uart_putsP(PSTR("No presense pulse found\n\r"));
+		    break;
+		    
+		case OW_BADCRC:
+		    uart_putsP(PSTR("Bad CRC\n\r"));
+		    break;
+
+		case OW_NOMODULES:
+		case OW_FOUND:
+		    break;
+		    
+		default:
+		    uart_putsP(PSTR("Unknown error from 1 wire library\n\r"));
+		    break;
+		}
+		
+		if (i != OW_FOUND)
+		    break;
+		
 		sprintf_P(cmdbuf, PSTR("%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n\r"), 
 			  ROM[0],
 			  ROM[1],
@@ -310,7 +329,10 @@
 			  ROM[6],
 			  ROM[7]);
 		uart_puts(cmdbuf);
-	    } while (OWNext(ROM, 1, 0));
+
+		i = OWNext(ROM, 1, 0);
+	    } while (1);
+		
 #if 0
 
 	} else if (cmdbuf[0] == 'l' && cmdbuf[1] == 'e' && cmdbuf[2] == 'd') {