void setup_DS1820(void) {
onewire_start();
if ( !onewire_search(DS1820_addr)) {
onewire_reset_search();
delayMs(250);
onewire_search(DS1820_addr);
}
if ( onewire_crc8( DS1820_addr, 7) != DS1820_addr[7]) {
respondstr = "No OneWire devices found";
return;
}
if ( DS1820_addr[0] == 0x10) {
is_DS18B20 = FALSE;
} else if ( DS1820_addr[0] == 0x28) {
is_DS18B20 = TRUE;
} else {
respondstr = "No DS1820 found";
return;
}
start_DS1820();
ds1820_time = getMs();
}
// Lua: r = ow.search( id )
static int ow_search( lua_State *L )
{
unsigned id = luaL_checkinteger( L, 1 );
MOD_CHECK_ID( ow, id );
luaL_Buffer b;
luaL_buffinit( L, &b );
char *p = luaL_prepbuffer(&b);
if(onewire_search(id, (uint8_t *)p)){
luaL_addsize(&b, 8);
luaL_pushresult( &b );
} else {
luaL_pushresult(&b); /* close buffer */
lua_pop(L,1);
lua_pushnil(L);
}
return 1;
}
int ICACHE_FLASH_ATTR ds18b20_read(ds18b20_data *read) {
byte i;
byte present = 0;
byte type_s;
byte data[12];
byte addr[8];
byte crc;
float celsius;
//float fahrenheit;
DS18B20_DBG("Look for OneWire Devices on PIN =%d", gpioPin);
if (!onewire_search(gpioPin, addr)) {
DS18B20_DBG("No more addresses.");
onewire_reset_search(gpioPin);
delay_ms(250);
return;
}
DS18B20_DBG("ADDRESS = %02x %02x %02x %02x %02x %02x %02x %02x",
addr[0], addr[1], addr[2], addr[3],
addr[4], addr[5], addr[6], addr[7]);
// the first ROM byte indicates which chip
switch (addr[0]) {
case 0x10:
DS18B20_DBG(" Chip = DS18S20"); // or old DS1820
type_s = 1;
break;
case 0x28:
DS18B20_DBG(" Chip = DS18B20");
type_s = 0;
break;
case 0x22:
DS18B20_DBG(" Chip = DS1822");
type_s = 0;
break;
default:
DS18B20_DBG("Device is not a DS18x20 family device.");
return;
}
onewire_reset(gpioPin);
onewire_select(gpioPin, addr);
onewire_write(gpioPin, 0x44, 1);
// start conversion, use ds.write(0x44,1) with parasite power on at the end
delay_ms(1000);
present = onewire_reset(gpioPin);
onewire_select(gpioPin, addr);
onewire_write(gpioPin, 0xBE, 1); // Read Scratchpad
//DS18B20_DBG(" Present = %d", present);
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = onewire_read(gpioPin);
DS18B20_DBG(" DATA: %02x ", data[i]);
}
crc = onewire_crc8(data, 8);
DS18B20_DBG(" CRC=%d ", crc);
if (crc != data[8]) {
DS18B20_DBG("CRC is not valid!");
return;
}
// 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.
int16_t 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 {
byte 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
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
//// default is 12 bit resolution, 750 ms conversion time
}
celsius = (float) raw / 16.0;
//fahrenheit = celsius * 1.8 + 32.0;
read->temp = celsius;
DS18B20_DBG("Temperature = ");
char *temp_string = (char*) os_zalloc(64);
c_sprintf(temp_string, "%f", read->temp);
DS18B20_DBG(" %s Celsius", temp_string);
os_free(temp_string);
//DS18B20_DBG(" %2.2f Fahrenheit", fahrenheit);
return 1;
}