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. More...

int16_t	mq3_read_raw (const mq3_t *dev)
	Read the RAW sensor value, can be between 0 and MQ3_MAX_RAW_VALUE. More...

int16_t	mq3_read (const mq3_t *dev)
	Read the scaled sensor value of PPM of alcohol. More...

Function Documentation

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

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

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