Hi all,

I want ask for help. I have 2 ESP32 with 2 environmental modules CCS811 + BME280 and have 2 problems.

First problem is, that readings aro not accurate (temperature, hunidity). Temperature on the first module is around 3 degrees C higher than temp measured with 3 other temp meters, but it is not linear so i cant count with it. Humidity is also moch lower than other meaurements about 15. The second one is about 1 degree on temp and 5 on humidity so not so different but beyond standard (±0.5℃ temperature error and ±2%RH humidity error). Does wire lenght, diametter or other variables affect the readings (on my test no, but i want to be sure) ?

On one of beetle i have problem with readings of air quality. There are nearly no readings at all. Sometimes it gets one per day (with 1 minute sampling) no matter which of two module i attache to it (both works fine on the other beetle).

Here is my code

#include <DFRobot_ENS160.h>
#include "DFRobot_BME280.h"
#include <SPI.h>
#include "WiFi.h"

#define SEA_LEVEL_PRESSURE 1015.0f

DFRobot_ENS160_I2C ENS160(&Wire, /*i2cAddr*/ 0x53);
typedef DFRobot_BME280_IIC BME; // ******** use abbreviations instead of full names ********
BME bme(&Wire, 0x76); // select TwoWire peripheral and set sensor address

char server[] = "server_address";
// piny pro připojení Trig a Echo z modulu
WiFiClient client;

// inicializace proměnných, do kterých se uloží data
//long temp, press, alti, humi;

float temp, alti, humi, tempe;
uint32_t press;
uint8_t Status, AQI;
uint16_t TVOC, ECO2;

const char* ssid = "SSID"; // The SSID (name) of the Wi-Fi network you want to connect to
const char* password = "password"; // The password of the Wi-Fi network

// show last sensor operate status
void printLastOperateStatus(BME::eStatus_t eStatus)
{
switch(eStatus) {
case BME::eStatusOK: Serial.println("everything ok"); break;
case BME::eStatusErr: Serial.println("unknow error"); break;
case BME::eStatusErrDeviceNotDetected: Serial.println("device not detected"); break;
case BME::eStatusErrParameter: Serial.println("parameter error"); break;
default: Serial.println("unknow status"); break;
}
}

void setup(void)
{
Serial.begin(115200);
bme.reset();

WiFi.begin(ssid, password); // Connect to the network
Serial.print("Connecting to ");
Serial.print(ssid); Serial.println(" ...");

int i = 0;
while (WiFi.status() != WL_CONNECTED) { // Wait for the Wi-Fi to connect
delay(1000);
Serial.print(++i); Serial.print(' ');
}

Serial.println("bme read data test");
while(bme.begin() != BME::eStatusOK) {
Serial.println("bme begin faild");
printLastOperateStatus(bme.lastOperateStatus);
delay(2000);
}
Serial.println("bme begin success");
delay(100);
// Init the sensor
while( NO_ERR != ENS160.begin() ){
Serial.println("Communication with device failed, please check connection");
delay(3000);
}

/**
* Set power mode
* mode Configurable power mode:
* ENS160_SLEEP_MODE: DEEP SLEEP mode (low power standby)
* ENS160_IDLE_MODE: IDLE mode (low-power)
* ENS160_STANDARD_MODE: STANDARD Gas Sensing Modes
*/
ENS160.setPWRMode(ENS160_STANDARD_MODE);

/**
* Users write ambient temperature and relative humidity into ENS160 for calibration and compensation of the measured gas data.
* ambientTemp Compensate the current ambient temperature, float type, unit: C
* relativeHumidity Compensate the current ambient temperature, float type, unit: %rH
*/
ENS160.setTempAndHum(/*temperature=*/bme.getTemperature(), /*humidity=*/bme.getHumidity());

}

void loop()
{
temp = bme.getTemperature();
press = bme.getPressure();
alti = bme.calAltitude(SEA_LEVEL_PRESSURE, press);
humi = bme.getHumidity();

Serial.println();
Serial.println("======== start print ========");
Serial.print("temperature (unit Celsius): "); Serial.println(temp);
Serial.print("pressure (unit pa): "); Serial.println(press);
Serial.print("altitude (unit meter): "); Serial.println(alti);
Serial.print("humidity (unit percent): "); Serial.println(humi);
Serial.println("======== end print ========");
/**
* Get the sensor operating status
* Return value: 0-Normal operation,
* 1-Warm-Up phase, first 3 minutes after power-on.
* 2-Initial Start-Up phase, first full hour of operation after initial power-on. Only once in the sensor’s lifetime.
* note: Note that the status will only be stored in the non-volatile memory after an initial 24h of continuous
* operation. If unpowered before conclusion of said period, the ENS160 will resume "Initial Start-up" mode
* after re-powering.
*/
Status = ENS160.getENS160Status();
Serial.print("Sensor operating status : ");
Serial.println(Status);
/**
* Get the air quality index
* Return value: 1-Excellent, 2-Good, 3-Moderate, 4-Poor, 5-Unhealthy
*/
AQI = ENS160.getAQI();
Serial.print("Air quality index : ");
Serial.println(AQI);

/**
* Get TVOC concentration
* Return value range: 0–65000, unit: ppb
*/
TVOC = ENS160.getTVOC();
Serial.print("Concentration of total volatile organic compounds : ");
Serial.print(TVOC);
Serial.println(" ppb");

/**
* Get CO2 equivalent concentration calculated according to the detected data of VOCs and hydrogen (eCO2 – Equivalent CO2)
* Return value range: 400–65000, unit: ppm
* Five levels: Excellent(400 - 600), Good(600 - 800), Moderate(800 - 1000),
* Poor(1000 - 1500), Unhealthy(> 1500)
*/
ECO2 = ENS160.getECO2();
Serial.print("Carbon dioxide equivalent concentration : ");
Serial.print(ECO2);
Serial.println(" ppm");
Serial.println();

Sending_To_phpmyadmindatabase_temp();

delay(60000);
}

void Sending_To_phpmyadmindatabase_temp() //CONNECTING WITH MYSQL
{
if (client.connect(server, 80)) {
Serial.println("connected");
// Make a HTTP request:
Serial.print(server);
Serial.print("GET /dht_temp.php?temp=");
client.print("GET /dht_temp.php?temp=");
client.print(temp); //YOUR URL
client.print("&press=");
client.print(press);
client.print("&alti=");
client.print(alti);
client.print("&humi=");
client.print(humi);
client.print("&Status=");
client.print(Status);
client.print("&AQI=");
client.print(AQI);
client.print("&TVOC=");
client.print(TVOC);
client.print("&ECO2=");
client.print(ECO2);

client.print(" "); //SPACE BEFORE HTTP/1.1
client.print("HTTP/1.1");
client.println();
client.println("Host: server_address);
client.println("Connection: close");
client.println();
} else {
// if you didn't get a connection to the server:
Serial.println("connection failed");
}
}