void setup() {
Serial.begin(9600);
}
void loop() {
sensorValue = analogRead(A0); //tried 14 with same results...
Serial.print("sensor = " );
Serial.println(sensorValue);
delay(10);
}
At my serial box i get only 1023.... this is it... If i messure the voltage with voltmeter , it works , it increases volts when it detects gas... from 5.10V it goes to 5.16V
How can i make it work ? thanks !
invader7:
void setup() {
Serial.begin(9600);
}
void loop() {
sensorValue = analogRead(A0); //tried 14 with same results...
Serial.print("sensor = " );
Serial.println(sensorValue);
delay(10);
}
At my serial box i get only 1023.... this is it... If i messure the voltage with voltmeter , it works , it increases volts when it detects gas... from 5.10V it goes to 5.16V How can i make it work ? thanks !
That sounds a little confusing. Any voltage equal to or over 5.000 VDC applied to a analog input pin will return only 1023 counts. Valid DC voltage range for a analog input pin is 0 to 5vdc only. So 5.1V and 5.16V will both return 1023 values. Maybe a link to your sensor will help us help you.
Lefty
Tutorial Arduino Your Home & Environment: Gas Sensor Tutorial
Datasheet http://www.pololu.com/file/0J309/MQ2.pdf
Tutorial http://www.geeetech.com/wiki/index.php/Gas_Sensor_-_MQ-2
What value load resistor are you using with your sensor? Sounds like it's best to use a 20K pot as a load resistor so you can 'calibrate' the sensor such that it's maximum value will be less the 5vdc output that the arduino analog input pin can handle correctly.
Lefty
I used 20k? resistor... im woried about connecting it correct... which way is the correct ?
this Arduino Your Home & Environment: Gas Sensor Tutorial is a littel confusing...
If you can post a drawing on how you specifically wired it up including wiring to the arduino board and any external DC power supply, perhaps we can find a problem.
Lefty
I think your resistor is too high. Try using 2k.
Do you know the basic information ? Arduino Playground - MQGasSensors
I was missing the 20k resistor between "Out" pin and GND , now i get value 730-780 when using analogread and >1000 when sensor is detecting a gas ! thanks guys , my bad....