pyupm_mhz16 module

class pyupm_mhz16.MHZ16(uart)

Bases: object

API support for the Grove CO2 sensor.

ID: mhz16

Name: CO2 Sensor

Other Names: MHZ16 Serial CO2 Sensor

Category: gaseous

Manufacturer: seeed

Connection: uart

Link:http://wiki.seeed.cc/Grove-CO2_Sensor/ This class implements support for the Grove CO2 sensor.

Its CO2 detection range is 0-2,000 ppm. It requires a 2-3 minute warm- up time before reporting valid data.

C++ includes: mhz16.hpp

calibrateZeroPoint()

void calibrateZeroPoint()

Sets the zero point of the sensor

dataAvailable(millis)

bool dataAvailable(unsigned int millis)

Checks to see if there is data available for reading

millis: Number of milliseconds to wait; 0 means no waiting.

True if there is data available for reading

getData()

bool getData()

Queries the sensor and gets the gas (CO2) concentration and temperature data. Should be called before other “get” functions.

True if successful

getGas()

int getGas()

Returns the gas (CO2) concentration data.

Gas concentration

getTemperature()

int getTemperature()

Returns the temperature data.

Temperature in Celsius

readData(buffer, len)

int readData(char *buffer, int len)

Reads any available data in a user-supplied buffer. Note: the call blocks until data is available to be read. Use dataAvailable() to determine whether there is data available beforehand, to avoid blocking.

buffer: Buffer to hold the data read

len: Length of the buffer

Number of bytes read

setupTty(*args)

bool setupTty(speed_t baud=B9600)

Sets up proper tty I/O modes and the baud rate. The default baud rate is 9,600 (B9600).

baud: Desired baud rate.

True if successful

verifyPacket(pkt, len)

bool verifyPacket(uint8_t *pkt, int len)

Verifies the packet header and indicates its validity

pkt: Packet to check

True if the checksum is valid, false otherwise

writeData(buffer, len)

int writeData(char *buffer, int len)

Writes the data in the buffer to the device

buffer: Buffer to hold the data read

len: Length of the buffer

Number of bytes written