- Tue Apr 11, 2017 1:21 pm
#64839
Hello,
I have a Wemos hooked up to a CO2 sensor reading values over I2C.
The CO2 sensor is powered by a separate 12V power supply. I have experimented with powering the Wemos through the serial port attached to a computer and through multiple different cell phone wall plugs.
No matter what I try, the ESP runs the code flawlessly between 3 to 6 times and then only reports 0. Because it only reads 0, the code just loops constantly through trying to get a better/accurate reading. I really don't know if this is a hardware or code issue.
If someone would be kind enough to review the code or offer any suggestions about how to troubleshoot this, it would be greatly appreciated. I'm not sure if the ESP is resetting, running out of RAM, or if its'a completely unrelated problem. I guess I'm asking if there's any known problems with the ESP internally resetting and not continuing to run code. It doesn't appear to turn off though... I'm really at a loss.
Thanks in advance,
Chase
I have a Wemos hooked up to a CO2 sensor reading values over I2C.
The CO2 sensor is powered by a separate 12V power supply. I have experimented with powering the Wemos through the serial port attached to a computer and through multiple different cell phone wall plugs.
No matter what I try, the ESP runs the code flawlessly between 3 to 6 times and then only reports 0. Because it only reads 0, the code just loops constantly through trying to get a better/accurate reading. I really don't know if this is a hardware or code issue.
If someone would be kind enough to review the code or offer any suggestions about how to troubleshoot this, it would be greatly appreciated. I'm not sure if the ESP is resetting, running out of RAM, or if its'a completely unrelated problem. I guess I'm asking if there's any known problems with the ESP internally resetting and not continuing to run code. It doesn't appear to turn off though... I'm really at a loss.
Thanks in advance,
Chase
Code: Select all
#include <Wire.h>
#include <ESP8266WiFi.h> //enable ESP8266 Wifi Library
#include <PubSubClient.h> //enable MQTT Library
/////////////////////////////////////////////
/////// Wifi Variables //////////////////////
/////////////////////////////////////////////
const char* ssid = "greauxeng"; //Internet Network Name
const char* password = "thankful4242"; //Wifi Password
const char* mqtt_server = "192.168.0.1"; //MQTT Server IP Address
WiFiClient espClient; //Create Wifi client named espClient
char c[8];
/////////////////////////////////////////////
// MQTT Variables ///////////////////////////
/////////////////////////////////////////////
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;
/////////////////////////////////////////////
// CO2 VARIABLES ////////////////////////////
/////////////////////////////////////////////
float min_diff = 50;
int CO2min = 200; //Below which CO2 is considered LOW
int CO2max = 800; //Above which CO2 is considered HIGH
int SolenoidPin = D8;
int SensorPin = D7;
int BuzzerPin = D5;
long previousMillis = 0;
long interval = 7000; //time to keep solenoid open
int diff1; //Stores the difference between sequential readings
int diff2;
int diff3;
int CO2_1; //Stores each CO2 reading
int CO2_2;
int CO2_3;
/////////////////////////////////////////////
// Wifi-Setup Function //////////////////////
/////////////////////////////////////////////
void setup_wifi() {
delay(10);
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.persistent(false); //These 3 lines are a required work around
WiFi.mode(WIFI_OFF); //otherwise the module will not reconnect
WiFi.mode(WIFI_STA); //if it gets disconnected
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
///////////////////////////////////////////////
// Callback Function //////////////////////////
///////////////////////////////////////////////
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
}
///////////////////////////////////////////////
// Reconnect Function /////////////////////////
///////////////////////////////////////////////
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
if (client.connect("ESP8266Client")) {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish("outTopic", "hello world");
// ... and resubscribe
client.subscribe("inTopic");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
//////////////////////////////////
//////////////////////////////////
// Read CO2 over I2C Function ////
//////////////////////////////////
//////////////////////////////////
int readCO2()
{
int co2Addr = 0x68; //address of CO2 sensor
int co2_value = 0; //CO2 value stored inside this variable.
//////////////////////////
/* Begin Write Sequence */
//////////////////////////
Wire.beginTransmission(co2Addr);
Wire.write(0x22);
Wire.write(0x00);
Wire.write(0x08);
Wire.write(0x2A);
Wire.endTransmission();
/////////////////////////
/* End Write Sequence. */
/////////////////////////
/*
We wait 10ms for the sensor to process our command.
The sensors's primary duties are to accurately
measure CO2 values. Waiting 10ms will ensure the
data is properly written to RAM
*/
delay(100);
/////////////////////////
/* Begin Read Sequence */
/////////////////////////
/*
Since we requested 2 bytes from the sensor we must
read in 4 bytes. This includes the payload, checksum,
and command status byte.
*/
Wire.requestFrom(co2Addr, 4);
byte i = 0;
byte buffer[4] = {0, 0, 0, 0};
/*
Wire.available() is not nessessary. Implementation is obscure but we leave
it in here for portability and to future proof our code
*/
while (Wire.available())
{
buffer[i] = Wire.read();
i++;
}
///////////////////////
/* End Read Sequence */
///////////////////////
/*
Using some bitwise manipulation we will shift our buffer
into an integer for general consumption
*/
co2_value = 0;
co2_value |= buffer[1] & 0xFF;
co2_value = co2_value << 8;
co2_value |= buffer[2] & 0xFF;
byte sum = 0; //Checksum Byte
sum = buffer[0] + buffer[1] + buffer[2]; //Byte addition utilizes overflow
if (sum == buffer[3])
{
return co2_value;
}
else
{
// Failure!
/*
Checksum failure can be due to a number of factors,
fuzzy electrons, sensor busy, etc.
*/
return 0;
}
}
void setup()
{
Serial.begin(9600);
Serial.println("The Greaux Engineering CO2 System is Active...");
pinMode(BuzzerPin, OUTPUT);
digitalWrite(BuzzerPin, LOW);
pinMode(SolenoidPin, OUTPUT);
digitalWrite(SolenoidPin, LOW);
Wire.begin();
delay(1000);
Serial.println("Initializing the Sensor...");
pinMode (SensorPin, OUTPUT);
digitalWrite(SensorPin, LOW);
delay(2000);
digitalWrite(SensorPin, HIGH);
Serial.println("Sensor Initialized");
delay(1000);
setup_wifi(); //run wifi setup function
client.setServer(mqtt_server, 1883); //Set MQTT server to port 1883
client.setCallback(callback); //Setup callback function
}
void loop()
{
////////////////////////////////////////
// Handeling Wifi disconnect ///////////
////////////////////////////////////////
if (!client.connected()) {
reconnect();
}
client.loop();
Serial.println("Measuring CO2:...");
/////////////////////////////////////////
//Trying to achieve an accurate CO2 Reading
////////////////////////////////////////
CO2_1 = readCO2();
Serial.println(CO2_1);
delay(4000);
CO2_2 = readCO2();
Serial.println(CO2_2);
delay(4000);
CO2_3 = readCO2();
Serial.println(CO2_3);
delay(4000);
if ((CO2_1 == 0) || (CO2_2 == 0) || (CO2_3 == 0))
{
Serial.println("Publish message: CO2 Value is Reading 0: SENSOR MALFUNCTION");
client.publish("sensor/co2/status", "SENSOR MALFUNCTION");
client.publish("sensor/co2/value", "0");
}
else {
diff1 = CO2_1 - CO2_2;
diff2 = CO2_2 - CO2_3;
diff3 = CO2_3 - CO2_1;
//////////////////////////////////////////
//If the difference between three readings
//is less than what we set, we can assume
//reading is accurate. If not we skip back up
//and take 3 more readings
//////////////////////////////////////////
Serial.println("The differences between values are");
Serial.println(fabs(diff1));
delay(500);
Serial.println(fabs(diff2));
delay(500);
Serial.println(fabs(diff3));
delay(500);
if ((fabs(diff1) <= min_diff) && (fabs(diff2) <= min_diff) && (fabs(diff3) <= min_diff))
{
Serial.println("CO2 Reading is ACCURATE...");
client.publish("sensor/co2/status", "CO2 Reading is ACCURATE...");
///////////////////////////////////////////////////////
//Once we have an accurate reading, if the
//CO2 level is outside our acceptable range
//we open the solenoid for a specified amount of time
//The millis stuff keeps looping the code until
//we reach our set time interval
/////////////////////////////////////////////////////
if (CO2_3 <= CO2min) {
Serial.print("Publish message: CO2 Reading is LOW: ");
Serial.println(CO2_3);
Serial.println("RELEASING CO2");
client.publish("sensor/co2/status","LOW.");
snprintf(msg, 75, "%ld", CO2_3);
client.publish("sensor/co2/value", msg);
client.publish("sensor/co2/status","RELEASING CO2");
unsigned long currentMillis = millis();
Serial.println(currentMillis);
while (abs(currentMillis - millis()) < interval)
{
digitalWrite(SolenoidPin, HIGH);
}
delay(7000);
Serial.println(millis());
digitalWrite(SolenoidPin, LOW);
client.publish("sensor/co2/status", "END RELEASE CO2");
}
else if ((CO2_3 > CO2min) && (CO2_3 < CO2max)) {
Serial.println("CO2 is IN RANGE");
Serial.println(CO2_3);
client.publish("sensor/co2/status","IN RANGE");
snprintf(msg, 75, "%ld", CO2_3);
client.publish("sensor/co2/value", msg);
delay(1000);
}
else {
Serial.println("CO2 is HIGH");
Serial.println(CO2_3);
tone(BuzzerPin, 2000, 10000);
client.publish("sensor/co2/status", "HIGH");
snprintf(msg, 75, "%ld", CO2_3);
client.publish("sensor/co2/value", msg);
delay(1000);
}
}
else
{
Serial.println("Reading is NOT ACCURATE. BEGINNING NEW READINGS...");
Serial.println(CO2_3);
client.publish("sensor/co2/status", "CO2 Reading is NOT ACCURATE");
snprintf(msg, 75, "%ld", CO2_3);
client.publish("sensor/co2/value", msg);
client.publish("sensor/co2/status", "BEGINNING NEW READINGS");
delay(1000);
}
}
delay(2000);
}
