kopia lustrzana https://github.com/micropython/micropython-lib
107 wiersze
3.9 KiB
Python
107 wiersze
3.9 KiB
Python
![]() |
from machine import I2C
|
||
|
from utime import sleep, sleep_ms
|
||
|
|
||
|
# Sensor Register Address Stack
|
||
|
#_PASCO2_REG_PROD_ID = const(0x00) # Product and revision ID register address
|
||
|
_PASCO2_REG_SENS_STS = const(0x01) # Sensor status register address
|
||
|
_PASCO2_REG_MEAS_RATE_H = const(0x02) # Measurement period MSB configuration register address
|
||
|
#_PASCO2_REG_MEAS_RATE_L = const(0x03) # Measurement period LSB register address
|
||
|
_PASCO2_REG_MEAS_CFG = const(0x04) # Measurement mode configuration register address
|
||
|
_PASCO2_REG_CO2PPM_H = const(0x05) # CO2 concentration result MSB register address
|
||
|
#_PASCO2_REG_CO2PPM_L = const(0x06) # CO2 concentration result LSB register address
|
||
|
_PASCO2_REG_MEAS_STS = const(0x07) # Measurement status register address
|
||
|
#_PASCO2_REG_INT_CFG = const(0x08) # Interrupt pin configuration register address
|
||
|
#_PASCO2_REG_ALARM_TH_H = const(0x09) # Alarm threshold MSB register address
|
||
|
_PASCO2_REG_SENS_RST = const(0x10) # Soft reset register address
|
||
|
|
||
|
#Error codes
|
||
|
_PASCO2_SUCCESS = 0
|
||
|
_PASCO2_ERROR = -1
|
||
|
|
||
|
addr = 0
|
||
|
mask = 1
|
||
|
|
||
|
i2c = I2C(0)
|
||
|
|
||
|
class PASCO2:
|
||
|
"""IFX - XENSIV PAS CO2 sensor driver"""
|
||
|
regMap = { # RegAddr, Mask
|
||
|
'REG_SENS_STS_BITF_SENS_RDY' : [_PASCO2_REG_SENS_STS, 0x80],
|
||
|
'REG_MEAS_CFG_BITF_OP_MODE' : [_PASCO2_REG_MEAS_CFG, 0x03],
|
||
|
'REG_MEAS_STS_BITF_DATA_RDY' : [_PASCO2_REG_MEAS_STS, 0x10], # Data ready status bit
|
||
|
'REG_CO2PPM_H_BITF_CO2_PPM_H': [_PASCO2_REG_CO2PPM_H, 0xFF],
|
||
|
}
|
||
|
|
||
|
def __init__(self, bus, measInterval=10, sensorAddr=0x28):
|
||
|
self.bus = bus
|
||
|
self.sensorAddr = sensorAddr
|
||
|
self.measInterval = measInterval
|
||
|
self.softResetCode = b"\xa3"
|
||
|
|
||
|
def _read_reg(self, regAddr, bytesToRead=1):
|
||
|
readVal = self.bus.readfrom_mem(self.sensorAddr, regAddr, bytesToRead)
|
||
|
return readVal
|
||
|
|
||
|
def _write_reg(self, regAddr, writeData):
|
||
|
self.bus.writeto_mem(self.sensorAddr, regAddr, writeData)
|
||
|
|
||
|
def _is_sensor_ready(self):
|
||
|
reg = self.regMap['REG_SENS_STS_BITF_SENS_RDY']
|
||
|
return (self._read_reg(reg[addr])[0] & reg[mask])
|
||
|
|
||
|
def _soft_reset(self):
|
||
|
self._write_reg(_PASCO2_REG_SENS_RST, self.softResetCode)
|
||
|
|
||
|
def _set_mode(self, mode):
|
||
|
if mode == 'idle': modeVal = 0x00
|
||
|
if mode == 'continuous': modeVal = 0x02
|
||
|
|
||
|
reg = self.regMap['REG_MEAS_CFG_BITF_OP_MODE']
|
||
|
readData = self._read_reg(reg[addr])[0]
|
||
|
writeData = bytes([(readData & ~(reg[mask])) | modeVal])
|
||
|
self._write_reg(_PASCO2_REG_MEAS_CFG,writeData)
|
||
|
|
||
|
|
||
|
def initialize(self):
|
||
|
try:
|
||
|
# wait for sensor to be ready
|
||
|
sensor_ready = self._is_sensor_ready()
|
||
|
while not sensor_ready:
|
||
|
sleep(1)
|
||
|
sensor_ready = self._is_sensor_ready()
|
||
|
|
||
|
# soft reset sensor register
|
||
|
self._soft_reset()
|
||
|
sleep_ms(800)
|
||
|
|
||
|
# set measure rate
|
||
|
buf = bytes([(self.measInterval >> 8) & 0xFF, self.measInterval & 0xFF])
|
||
|
self._write_reg(_PASCO2_REG_MEAS_RATE_H, buf)
|
||
|
|
||
|
# reset operation mode to idle mode
|
||
|
self._set_mode('idle')
|
||
|
|
||
|
# start continuous mode
|
||
|
self._set_mode('continuous')
|
||
|
|
||
|
return _PASCO2_SUCCESS
|
||
|
|
||
|
except:
|
||
|
return _PASCO2_ERROR
|
||
|
|
||
|
def getCO2Value(self):
|
||
|
while True:
|
||
|
try:
|
||
|
# get meas status
|
||
|
reg = self.regMap['REG_MEAS_STS_BITF_DATA_RDY']
|
||
|
readStatus = self._read_reg(reg[addr])
|
||
|
data_ready = readStatus[0] & reg[mask]
|
||
|
|
||
|
if data_ready:
|
||
|
# get CO2 value
|
||
|
reg = self.regMap['REG_CO2PPM_H_BITF_CO2_PPM_H']
|
||
|
readVal = self._read_reg(reg[addr], 2)
|
||
|
co2_value = (readVal[0] << 8) | readVal[1]
|
||
|
return co2_value
|
||
|
except:
|
||
|
return _PASCO2_ERROR
|