mqx.h File Reference

Include dependency graph for mqx.h:

API Description

The mqx gas sensor driver can be used to read a wide range of sensors. The list below shows the currently supported sensors:

 mq2: H2/LPG/CH4/CO/alcohol/smoke/propane/etc
     LPG/propane 200-5000 ppm
     butane 300-5000 ppm
     CH4 5000-2000 ppm
     H2 300-5000 ppm
     alcohol 100-2000 ppm
 mq3: Alcohol/benzine/CH4/hexane/LPG/CO .05-10 mg/L
 mq4: CNG (mostly methane) 200-10000 ppm
 mq5: H2/LPG/CH4/CO/alcohol 200-10000 ppm
 mq6: LPG (mostly propane/butane) 200-10000 ppm
 mq7: CO 20-2000 ppm
 mq8: H 100-10000 ppm
 mq9: CO/CH4/LPG 200-1000/10000/10000 ppm

Go to the source code of this file.

Data Structures
struct	_mqx_context

Functions
mqx_context	mqx_init (int16_t pin)
void	mqx_close (mqx_context dev)
upm_result_t	mqx_set_aref (const mqx_context dev, float aref)
upm_result_t	mqx_set_scale (const mqx_context dev, float scale)
upm_result_t	mqx_set_offset (const mqx_context dev, float offset)
float	mqx_get_aref (const mqx_context dev)
float	mqx_get_scale (const mqx_context dev)
float	mqx_get_offset (const mqx_context dev)
upm_result_t	mqx_get_normalized (const mqx_context dev, float *value)
upm_result_t	mqx_get_raw_volts (const mqx_context dev, float *value)
upm_result_t	mqx_get_volts (const mqx_context dev, float *value)

Typedefs
typedef struct _mqx_context *	mqx_context

Function Documentation

mqx_context mqx_init

(

int16_t

pin

)

Initialize analog sensor

Parameters

pin	Analog pin

Returns

sensor context

void mqx_close

(

mqx_context

dev

)

Analog sensor destructor

Parameters

sensor

context pointer

upm_result_t mqx_set_aref	(	const mqx_context	dev,
		float	aref
	)

Set ADC reference voltage

Parameters

dev	sensor context pointer
aref	ADC reference voltage

Returns

Function result code

upm_result_t mqx_set_scale	(	const mqx_context	dev,
		float	scale
	)

Set sensor scale. This scale is applied to the return value: counts = counts * scale

Parameters

dev	sensor context pointer
scale	count scale value used

Returns

Function result code

upm_result_t mqx_set_offset	(	const mqx_context	dev,
		float	offset
	)

Set sensor offset. This offset is applied to the return value: counts = counts + offset

Parameters

dev	sensor context pointer
offset	count offset value used

Returns

Function result code

float mqx_get_aref

(

const mqx_context

dev

)

Get sensor aref

Parameters

dev	sensor context pointer

Returns

Sensor ADC reference voltage

float mqx_get_scale

(

const mqx_context

dev

)

Get sensor scale

Parameters

dev	sensor context pointer

Returns

Sensor scale

float mqx_get_offset

(

const mqx_context

dev

)

Get sensor offset

Parameters

dev	sensor context pointer

Returns

Sensor offset

upm_result_t mqx_get_normalized	(	const mqx_context	dev,
		float *	value
	)

Read normalized value for sensor

Parameters

dev	sensor context pointer
*value	Normalized value (0.0 -> 1.0)

Returns

Function result code

upm_result_t mqx_get_raw_volts	(	const mqx_context	dev,
		float *	value
	)

Read raw voltage from the sensor

Parameters

dev	sensor context pointer
*value	Raw sensor voltage

Returns

Function result code

upm_result_t mqx_get_volts	(	const mqx_context	dev,
		float *	value
	)

Read scaled/offset voltage from the sensor

Parameters

dev	sensor context pointer
*value	Adjusted sensor voltage

Returns

Function result code

Typedef Documentation

typedef struct _mqx_context * mqx_context

driver context