ESP32 Next Generation IOT

Internet Of Things leicht gemacht

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Temperaturmessung mit ESP32 und LU90614 IRTempSensor

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LU90614 Uart Communication Protocol

• 1. Baud rate 9600, data bit 8, stop bit 1, no parity check;
• 2. The set parameters can be saved after power failure;
• 3. Temperature mode sending command: 0xFA 0xC5 0xBF
• 4. Material temperature mode sending command: 0xFA 0xC6 0xC0
• 5. Start measuring temperature and upload temperature command 0xFA 0xCA 0xC4
• 6. Temperature value return command: One packet of data:
  [header] [instruction] [ DataH ] [DataL] [ reserved byte1] [ reserved byte 2 ] [reserved byte 3] [ reserved bit 4 ] [check byte]

  header:	0xFE, which is a fixed header;
  Instruction:	0xAA, this is the material temperature mode the unit is Celsius 0xAC=Body!
  DataH	0xnnis the integer of material temperature
  DataL	0xnnis the decimal place

• 7. Example 1 (measuring the current " ambient"temperature):

  Send: →	0xFA 0xC6 0xC0(not sent if the current temperature measurement mode) 0xFA 0xCA 0xC4
  Return: ←	0xFE 0xAA 0x28 0x1E 0x00 0x00 0x00 0x00 0xEE Analysis of returned data: 0x28h=40d 0x1E=30d =>so the current material temperature is 40.30 °C. 0xFE + 0xAA + 0x28 + 0x1E + 0 + 0 + 0 +0 =0x1EE

• 7. Example 2 (measuring the current "body" temperature):

  Send: →	0xFA 0xC5 0xBF 0xFA 0xCA 0xC4
  Return: ←	0xFE 0xAC 0x28 0x1E 0x00 0x00 0x00 0x00 0xF0 Analysis of returned data: the current temperature is 40.3 °C.

#define pin_RXD2 16
#define pin_TXD2 17
#define LU90614_BAUD 9600
#define LU90614_AMBI "\xFA\xC6\xC0"
#define LU90614_READ "\xFA\xCA\xC4"

bool LU90614_debug()
{
	char ac_data[10]; int i_resp=0,i_checksum=0; float f_tambi;
	Serial2.print(LU90614_AMBI);
	Serial2.print(LU90614_READ); 
	long l_ms0=millis();
	while(Serial2.available()<9){Serial2.print("."); delay(1);} 
	Serial.printf("Response after %3d ms\r\n",millis()-l_ms0);
	for(int i=0;i<=7;i++){i_resp=Serial2.read(); i_checksum+=i_resp; ac_data[i]=i_resp; Serial.printf("%02X ",i_resp);} i_checksum%=256;
	i_resp=Serial2.read(); Serial.printf("chk:%02X==%02X ",i_resp,i_checksum);
	if(ac_data[3]!=0xFF)
	{
		if(ac_data[1]==0xAA){f_tambi=ac_data[2]+ac_data[3]/100.0; Serial.printf("Ambi:%.2f\r\n",f_tambi); }
		return true;
	}
	return false;
}

void setup() 
{
	Serial.begin(115200);
	Serial2.begin(LU90614_BAUD,SERIAL_8N1, pin_RXD2, pin_TXD2);
	Serial.printf("LU90614 TxD-->ESP.RX2D[GPIO%d] RxD<--ESP.TXD2[GPIO%d]\r\n",pin_RXD2,pin_TXD2);
}

void loop() 
{
	LU90614_debug();
}