MQ-3 Alcohol Tester

Device driver for the MQ-3 alcohol sensor. More...

Detailed Description

Device driver for the MQ-3 alcohol sensor.

Files
file	mq3.h
	Device driver interface for the MQ-3 alcohol sensor.

Data Structures
struct	mq3_t
	device descriptor for a MQ-3 sensor More...

Macros
#define	MQ3_MAX_RAW_VALUE   (1023U)
	maximum unprocessed value fetched form the sensor

Functions
int	mq3_init (mq3_t *dev, adc_t adc_line)
	Initialize a MQ-3 alcohol sensor.
int16_t	mq3_read_raw (const mq3_t *dev)
	Read the RAW sensor value, can be between 0 and MQ3_MAX_RAW_VALUE.
int16_t	mq3_read (const mq3_t *dev)
	Read the scaled sensor value of PPM of alcohol.

Macro Definition Documentation

MQ3_MAX_RAW_VALUE

#define MQ3_MAX_RAW_VALUE   (1023U)

maximum unprocessed value fetched form the sensor

Definition at line 33 of file mq3.h.

Function Documentation

mq3_init()

int mq3_init	(	mq3_t *	dev,
		adc_t	adc_line
	)

Initialize a MQ-3 alcohol sensor.

The MQ-3 sensor is interfaced by a single ADC pin, specified by adc and channel.

Note

The sensor needs about a minute to heat up before meaningful measurements can be made.

Parameters

[out]	dev	device descriptor of an MQ-3 sensor
[in]	adc_line	the ADC device the sensor is connected to

Return values

0	success
-1	failure

mq3_read()

int16_t mq3_read

(

const mq3_t *

dev

)

Read the scaled sensor value of PPM of alcohol.

Parameters

[in]

dev

device descriptor of the MQ-3 sensor to read from

Returns

the scaled sensor value in PPM of alcohol

mq3_read_raw()

int16_t mq3_read_raw

(

const mq3_t *

dev

)

Read the RAW sensor value, can be between 0 and MQ3_MAX_RAW_VALUE.

Parameters

[in]

dev

device descriptor of the MQ-3 sensor to read from

Returns

the raw sensor value, between 0 and MQ3_MAX_RAW_VALUE