![MQ135](/sdk/parts/MQ135/image.jpg)
- Found at :
MQ135
High sensitve multiple gas sensor especially for detecting air quality like NH3,NOx, alcohol, Benzene, smoke,CO2 ,etc..
If you are using just MQ135(not module), Then prepare load resistance around 2k ohm.
This sensor need pre-heating. To get stable output, wait for heat-up, minimum 2 minutes.
This library get analog voltage from a sensor. Output voltage will increase regarding gas level. When you need actual level (ppm), you should do calibrate the sensor and prepare a formula.
wired(obniz, { vcc, gnd, do, ao});
name | type | required | default | description |
---|---|---|---|---|
vcc | number(obniz Board io) |
no | VCC or H on MQ135. | |
gnd | number(obniz Board io) |
no | GND or H on MQ135. | |
do | number(obniz Board io) |
no | digital out | |
ao | number(obniz Board io) |
no | analog out |
// Javascript Example
var mq135 = obniz.wired("MQ135", {vcc:3, gnd:2, do:1, ao:0});
await mq135.heatWait();
mq135.onchangeanalog = function(voltage) {
console.log(voltage);
}
startHeating()
It start heating.
// Javascript Example
var mq135 = obniz.wired("MQ135", {vcc:3, gnd:2, do:1, ao:0});
mq135.startHeating();
[await] heatWait(sec: number)
It start heating and wait for a while.
You can update wait time.
name | type | required | default | description |
---|---|---|---|---|
sec | number |
no | 120 | seconds for wait |
// Javascript Example
var mq135 = obniz.wired("MQ135", {vcc:3, gnd:2, do:1, ao:0});
await mq135.heatWait();
mq135.onchangeanalog = function(voltage) {
console.log(voltage);
}
onchangeanalog = function(voltage: number)
Specified function will be called every voltage change.
// Javascript Example
var mq135 = obniz.wired("MQ135", {vcc:3, gnd:2, do:1, ao:0});
await mq135.heatWait();
mq135.onchangeanalog = function(voltage) {
console.log(voltage);
}
onexceedvoltage = function(voltage: number)
Specified function will be called only when a voltage exceed voltageLimit variable.
// Javascript Example
var mq135 = obniz.wired("MQ135", {vcc:3, gnd:2, do:1, ao:0});
await mq135.heatWait();
mq135.voltageLimit = 1.0
mq135.onexceedvoltage = function(voltage) {
console.log(voltage);
}
voltageLimit = number
It define the level of onexceedvoltage call.
// Javascript Example
var mq135 = obniz.wired("MQ135", {vcc:3, gnd:2, do:1, ao:0});
await mq135.heatWait();
mq135.voltageLimit = 1.0
mq135.onexceedvoltage = function(voltage) {
console.log(voltage);
}
onchangedigital = function(voltage: number)
This function only be called when do was specified at wired function.
do output high/low regarding output. It compared in a module.
This function will be called every change of do.
// Javascript Example
var mq135 = obniz.wired("MQ135", {vcc:3, gnd:2, do:1, ao:0});
await mq135.heatWait();
mq135.onchangedigital = function(value) {
console.log(value);
}
Supported from: obniz.js 3.5.0