feat: Improve DS1820 driver

New features:
* Handle all types of DS1820 tempature sensors by detecting the family of the sensor and calculating the temperature accordingly
* Clean up some log prints
* Set the channel value with current temperature
* Set the period of the conversion interval with an optional first parameter
* Start the conversion instantly and not wait for multiple of the conversion period

src/driver/drv_ds1820_simple.c

@@ -6,7 +6,8 @@ static int Pin;
 static int t=-127;
 static int errcount=0;
 static int lastconv; // secondsElapsed on last successfull reading
-
+static uint8_t ds18_family = 0;
+static int ds18_conversionPeriod = 0;
 
 // usleep adopted from DHT driver
 
@@ -356,8 +357,11 @@ int DS1820_getTemp() {
  return t;
 }
 
-
-void DS1820_driver_Init(){};
+// startDriver DS1820 [conversionPeriod (seconds) - default 15]
+void DS1820_driver_Init(){
+ ds18_conversionPeriod = Tokenizer_GetArgIntegerDefault(1, 15);
+ lastconv=0;
+};
 
 
 void DS1820_AppendInformationToHTTPIndexPage(http_request_t *request)
@@ -366,7 +370,38 @@ void DS1820_AppendInformationToHTTPIndexPage(http_request_t *request)
  hprintf255(request, "<h5>DS1820 Temperature: %.2f C (read %i secs ago)</h5>",(float)t/100, g_secondsElapsed-lastconv);
 }
 
+int DS1820_DiscoverFamily() {
+ if (!OWReset(Pin)) {
+ addLogAdv(LOG_DEBUG, LOG_FEATURE_CFG, "DS1820 - Pin=%i - Discover Reset failed",Pin);
+ return 0;
+ }
+
+ // Read ROM
+ uint8_t ROM[8];
+ OWWriteByte(Pin, 0x33);
+ for (int i = 0; i < 8; i++) {
+ ROM[i] = OWReadByte(Pin);
+ }
 
+ // Check CRC
+ uint8_t crc = Crc8CQuick(ROM, 7);
+ if (crc != ROM[7]) {
+ // This might mean bad signal integrity or multiple 1-wire devices on the bus
+ addLogAdv(LOG_DEBUG, LOG_FEATURE_CFG, "DS1820 - Pin=%i - Discover CRC=%x != calculated:%x",Pin, ROM[7], crc);
+ return 0;
+ }
+
+ // Check family
+ uint8_t family = ROM[0];
+ if (family == 0x10 || family == 0x28) {
+ ds18_family = family;
+ addLogAdv(LOG_DEBUG, LOG_FEATURE_CFG, "DS1820 - Pin=%i - Family %x",Pin, ds18_family);
+ return 1;
+ } else {
+ addLogAdv(LOG_DEBUG, LOG_FEATURE_CFG, "DS1820 - Pin=%i - Family %x not supported",Pin, family);
+ return 0;
+ }
+}
 
 void DS1820_OnEverySecond() {
 
@@ -379,10 +414,6 @@ void DS1820_OnEverySecond() {
  // if (dsread == 1 && g_secondsElapsed % 5 == 2) {
  // better if we don't use parasitic power, we can check if conversion is ready 
  if (dsread == 1 && DS1820TConversionDone(Pin) == 1) {
-
- uint8_t Low=0,High=0,negative=0;
- int Val,Tc;
-
  if (OWReset(Pin) == 0) addLogAdv(LOG_ERROR, LOG_FEATURE_CFG, "DS1820 - Pin=%i -- Reset failed",Pin); 
  OWWriteByte(Pin,0xCC);
  OWWriteByte(Pin,0xBE);
@@ -403,33 +434,36 @@ void DS1820_OnEverySecond() {
  } 
  else
  { 
- Low = scratchpad[0];
- High = scratchpad[1];
+ int16_t raw = (scratchpad[1] << 8) | scratchpad[0];
+
+ if (ds18_family == 0x10) { // DS18S20 or old DS1820
+ int16_t dT = 128 * (scratchpad[7] - scratchpad[6]);
+ dT /= scratchpad[7];
+ raw = 64 * (raw & 0xFFFE) - 32 + dT;
+ addLogAdv(LOG_DEBUG, LOG_FEATURE_CFG, "DS1820 - Pin=%i -- Family %x, raw %i, count_remain %i, count_per_c %i, dT %i",Pin, ds18_family, raw, scratchpad[6], scratchpad[7], dT);
+ } else { // DS18B20
+ uint8_t cfg = scratchpad[4] & 0x60;
+ if (cfg == 0x00) raw = raw & ~7; // 9 bit resolution, 93.75 ms
+ else if (cfg == 0x20) raw = raw & ~3; // 10 bit res, 187.5 ms
+ else if (cfg == 0x40) raw = raw & ~1; // 11 bit res, 375 ms
+ raw = raw << 3; // multiply by 8
+ addLogAdv(LOG_DEBUG, LOG_FEATURE_CFG, "DS1820 - Pin=%i -- Family %x, cfg %x, raw %i",Pin, ds18_family, cfg, raw);
+ }
 
+ // Raw is t * 128
+ t = (raw / 128) * 100; // Whole degrees
+ int frac = (raw % 128) * 100 / 128; // Fractional degrees
+ t += t > 0 ? frac : -frac;
 
- Val = (High << 8) + Low; // combine bytes to integer
- negative = (High >= 8); // negative temperature
- if (negative)
- {
- Val = (Val ^ 0xffff) + 1;
- }
- // Temperature is returned in multiples of 1/16 °C
- // we want a simple way to display e.g. xx.yy °C, so just multiply with 100 and we get xxyy 
- // --> the last two digits will be the fractional part (Val%100)
- // --> the whole part of temperature is (int)Val/100
- // so we want 100/16 = 6.25 times the value (the sign to be able to show negative temperatures is in "factor") 
- Tc = (6 * Val) + Val / 4 ;
- t = negative ? -1 : 1 * Tc ;
  dsread=0;
  lastconv=g_secondsElapsed;
- addLogAdv(LOG_INFO, LOG_FEATURE_CFG, "DS1820 - Pin=%i temp=%s%i.%02i \r\n",Pin, negative ? "-" : "+", (int)Tc/100 , (int)Tc%100);
- addLogAdv(LOG_INFO, LOG_FEATURE_CFG, "DS1820 - High=%i Low=%i Val=%i Tc=%i -- Read CRC=%x - calculated:%x \r\n",High, Low, Val,Tc,scratchpad[8],crc);
+ CHANNEL_Set(g_cfg.pins.channels[Pin], t, CHANNEL_SET_FLAG_SILENT);
+ addLogAdv(LOG_INFO, LOG_FEATURE_CFG, "DS1820 - Pin=%i temp=%i.%02i \r\n", Pin, (int)t/100 , (int)t%100);
  }
  }
- else if (g_secondsElapsed % 15 == 0) { // every 15 seconds
- // ask for "conversion" 
-
- if (OWReset(Pin) == 0){
+ else if (dsread == 0 && (g_secondsElapsed % ds18_conversionPeriod == 0 || lastconv == 0)) { 
+ if (OWReset(Pin) == 0) {
+ lastconv=-1; // reset lastconv to avoid immediate retry
  addLogAdv(LOG_ERROR, LOG_FEATURE_CFG, "DS1820 - Pin=%i -- Reset failed",Pin);
 
  // if device is not found, maybe "usleep" is not working as expected
@@ -459,6 +493,16 @@ void DS1820_OnEverySecond() {
 
  } 
  else {
+ if (ds18_family == 0) {
+ int discovered = DS1820_DiscoverFamily();
+ if (!discovered) {
+ lastconv=-1; // reset lastconv to avoid immediate retry
+ addLogAdv(LOG_ERROR, LOG_FEATURE_CFG, "DS1820 - Pin=%i -- Family not discovered",Pin);
+ return;
+ }
+ addLogAdv(LOG_INFO, LOG_FEATURE_CFG, "DS1820 - Pin=%i -- Family discovered %x",Pin, ds18_family);
+ }
+
  OWWriteByte(Pin,0xCC);
  OWWriteByte(Pin,0x44);
  addLogAdv(LOG_INFO, LOG_FEATURE_CFG, "DS1820 - asked for conversion - Pin %i",Pin);