From 8afa3e3f9de66d6ae11fc1a0ca839be31c327631 Mon Sep 17 00:00:00 2001
From: Bernhard Tittelbach <xro@realraum.at>
Date: Sat, 3 Aug 2013 04:45:35 +0000
Subject: ds18x20 onewire temp sensor example

git-svn-id: https://svn.spreadspace.org/avr/trunk@210 aa12f405-d877-488e-9caf-2d797e2a1cc7
---
 usb-1wire/usb-1wire.c | 226 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 197 insertions(+), 29 deletions(-)

(limited to 'usb-1wire/usb-1wire.c')

diff --git a/usb-1wire/usb-1wire.c b/usb-1wire/usb-1wire.c
index a383ef1..6fed4f5 100644
--- a/usb-1wire/usb-1wire.c
+++ b/usb-1wire/usb-1wire.c
@@ -1,8 +1,10 @@
 /*
- *  spreadspace avr utils
+ *  spreadspace avr utils - usb-1wire example
  *
  *
- *  Copyright (C) 2013 Christian Pointner <equinox@spreadspace.org>
+ *  Copyright (C) 2013 Bernhard Tittelbach <xro@realraum.at>
+ *  basically this is refactored and enhanced code from:
+ *   http://www.pjrc.com/teensy/td_libs_OneWire.html
  *
  *  This file is part of spreadspace avr utils.
  *
@@ -24,45 +26,211 @@
 #include <avr/io.h>
 #include <avr/wdt.h>
 #include <avr/interrupt.h>
-#include <avr/power.h>
+#include <util/delay.h>
 #include <stdio.h>
 
 #include "util.h"
 #include "led.h"
 #include "usbio.h"
 
+#include "onewire.h"
+
+#define MAX_OWI_DEVICES 3
+
+uint8_t owi_addr_[MAX_OWI_DEVICES][8];
+uint8_t num_owi_dev_found_;
+
+void discoverOWIBus(void)
+{
+    uint8_t d=0;
+    led_on();
+
+    printf("Searching OW Bus ");
+    num_owi_dev_found_ = 0;
+    if (owi_reset())
+        printf(" !something is there! ");
+    owi_reset_search();
+    _delay_ms(250);
+    
+    //Search only for DS1820 temp sensors
+    owi_target_search(DS1820_FAMILY_ID);
+    
+    while ( owi_search(owi_addr_[ d ]))
+    {
+        d++;
+        printf("%d. found, ", d);
+        led_toggle();
+        if ( d >= MAX_OWI_DEVICES)
+            break;
+    }
+    num_owi_dev_found_ = d;
+    printf(" done \r\n");
+    printf("%d devices found\r\n", d);
+    
+    for (d=0; d<num_owi_dev_found_; d++)
+    {
+        printf("OW Dev #%d: addr = ", d);
+        for (uint8_t a=0;  a<8; a++)
+            printf("%02x ", owi_addr_[d][a]);
+        if (owi_crc8(owi_addr_[d], 7) == owi_addr_[d][7])
+            printf("  CRC OK");
+        else
+            printf("  CRC ERROR");        
+        printf("\r\n");
+    }
+    led_off();
+}
+
+void tempToUSB(uint8_t resolution) 
+{
+    uint8_t data[9];
+    int16_t celsius = 0;
+    int16_t raw = 0;
+    uint8_t type_s, cfg;
+    uint8_t d=0;
+    uint8_t cfg_res=12;
+    uint8_t crc_result = 0;
+    
+    led_on();
+
+    owi_reset();
+    //we assume we do NOT use parasitic power, so we can issue
+    //commands while other sensors are already busy converting
+    for (d=0; d<num_owi_dev_found_; d++)
+    {
+        owi_select(owi_addr_[d]);
+        
+        owi_write(DS1820_WRITE_SCRATCHPAD, 0);
+        owi_write(0xFF, 0);
+        owi_write(0x7F, 0);
+        owi_write(resolution | 0x1F, 0);
+        owi_reset();
+        owi_select(owi_addr_[d]);
+        owi_write(DS1820_START_CONVERSION, 0);
+    }
+
+    switch (resolution) 
+    {
+            case DS1820_RESOLUTION_9BITS: _delay_ms(DS1820_TCONV_MS_9BITS); break;
+            case DS1820_RESOLUTION_10BITS: _delay_ms(DS1820_TCONV_MS_10BITS); break;
+            case DS1820_RESOLUTION_11BITS: _delay_ms(DS1820_TCONV_MS_11BITS); break;
+            default: _delay_ms(DS1820_TCONV_MS_12BITS); break;
+    }
+    
+    if (owi_reset()) //reset is needed
+        printf("Sensor present\r\n");
+    else
+        printf("Sensor NOT present\r\n");    
+    
+    for (d=0; d<num_owi_dev_found_; d++)
+    {
+        owi_select(owi_addr_[d]);
+        owi_write(DS1820_READ_SCRATCHPAD, 0);         // Read Scratchpad
+        printf("Data: ");
+        for (uint8_t i = 0; i < 9; i++) {          // we need 9 bytes
+            data[i] = owi_read();
+            printf("%02x " , data[i]);
+        }
+        crc_result = owi_crc8(data,8);
+        printf(" crc: %x is %s\r\n" , crc_result, (crc_result == data[8])? "OK": "ERRORENOUS");
+
+        // the first ROM byte indicates which chip
+        switch (owi_addr_[d][0]) 
+        {
+            case 0x10:
+                //~ Serial.println("  Chip = DS18S20");  // or old DS1820
+                type_s = 1;
+                break;
+            case 0x28:
+                //~ Serial.println("  Chip = DS18B20");
+                type_s = 0;
+                break;
+            case 0x22:
+                //~ Serial.println("  Chip = DS1822");
+                type_s = 0;
+                break;
+            default:
+                continue;
+        } 
+        
+        // Convert the data to actual temperature
+        // because the result is a 16 bit signed integer, it should
+        // be stored to an "int16_t" type, which is always 16 bits
+        // even when compiled on a 32 bit processor.
+        raw = (data[1] << 8) | data[0];
+        if (type_s)
+        {
+            raw = raw << 3; // 9 bit resolution default
+            if (data[7] == 0x10) {
+                // "count remain" gives full 12 bit resolution
+                raw = (raw & 0xFFF0) + 12 - data[6];
+            }
+        } else {
+            cfg = (data[4] & 0x60);
+            // at lower res, the low bits are undefined, so let's zero them
+            if (cfg == 0x00)
+            {
+                raw = raw & ~7;  // 9 bit resolution, 93.75 ms
+                cfg_res = 9;
+            }
+            else if (cfg == 0x20)
+            {
+                raw = raw & ~3; // 10 bit res, 187.5 ms
+                cfg_res = 10;
+            }
+            else if (cfg == 0x40)
+            {
+                raw = raw & ~1; // 11 bit res, 375 ms
+                cfg_res = 11;
+            }
+        //// default is 12 bit resolution, 750 ms conversion time
+        }
+        celsius = raw / 16;
+      
+        printf("Temperature: raw %d, celsius: %d, resolution: %d bits\r\n", raw, celsius, cfg_res);
+    }
+    led_off();
+}
+
+
 void handle_cmd(uint8_t cmd)
 {
-  switch(cmd) {
-  case '0': led_off(); break;
-  case '1': led_on(); break;
-  case 't': led_toggle(); break;
-  case 'r': reset2bootloader(); break;
-  default: printf("error\r\n"); return;
-  }
-  printf("ok\r\n");
+    switch(cmd) {
+        case '0': discoverOWIBus(); break;
+        case '1': tempToUSB(DS1820_RESOLUTION_9BITS); break;
+        case '2': tempToUSB(DS1820_RESOLUTION_10BITS); break;
+        case '3': tempToUSB(DS1820_RESOLUTION_11BITS); break;
+        case '4': tempToUSB(DS1820_RESOLUTION_12BITS); break;
+        case 'r': reset2bootloader(); break;
+        default: printf("error\r\n"); return;
+    }
+    printf("ok\r\n");
 }
 
 int main(void)
 {
-  MCUSR &= ~(1 << WDRF);
-  wdt_disable();
-
-  cpu_init();
-  led_init();
-  usbio_init();
-  sei();
-
-  for(;;) {
-    int16_t BytesReceived = usbio_bytes_received();
-    while(BytesReceived > 0) {
-      int ReceivedByte = fgetc(stdin);
-      if(ReceivedByte != EOF) {
-        handle_cmd(ReceivedByte);
-      }
-      BytesReceived--;
-    }
+    MCUSR &= ~(1 << WDRF);
+    wdt_disable();
+
+    cpu_init();
+    led_init();
+    usbio_init();
+    sei();
+    DDRC &= ~7;
+    owi_init(7, &PINC);
+
+    for(;;) 
+    {
+        int16_t BytesReceived = usbio_bytes_received();
+        while(BytesReceived > 0) 
+        {
+            int ReceivedByte = fgetc(stdin);
+            if(ReceivedByte != EOF) {
+                handle_cmd(ReceivedByte);
+            }
+            BytesReceived--;
+        }
 
     usbio_task();
-  }
+    }
 }
-- 
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