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Added test, fixed typo

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This commit is contained in:
Conr86
2019-06-22 17:15:44 +10:00
parent 75457cdad8
commit e7cb94e364
3 changed files with 63 additions and 49 deletions
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16
sgp30/crc.py
View File

@@ -1,23 +1,23 @@
class Crc8:
def __init__(s):
s.crc=255
s.crc = 255
def hash(s,int_list):
def hash(s, int_list):
for i in int_list:
s.addVal(i)
return s.crc
def addVal(s,n):
def addVal(s, n):
crc = s.crc
for bit in range(0,8):
if ( n ^ crc ) & 0x80:
crc = ( crc << 1 ) ^ 0x31
for bit in range(0, 8):
if (n ^ crc) & 0x80:
crc = (crc << 1) ^ 0x31
else:
crc = ( crc << 1 )
crc = (crc << 1)
n = n << 1
s.crc = crc & 0xFF
return s.crc
#print(Crc8().hash([1,144]))
# print(Crc8().hash([1,144]))
#print(hex(Crc8().hash([0xBE, 0xEF])))
#[1, 144, 76, 0, 6, 39]

77
sgp30/sgp30.py
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@@ -2,7 +2,7 @@ import smbus2
from smbus2 import SMBusWrapper, SMBus, i2c_msg
from collections import namedtuple
from functools import partial
from time import sleep, asctime,time
from time import sleep, asctime, time
import json
from copy import copy
import os.path
@@ -11,58 +11,60 @@ from .crc import Crc8
DEVICE_BUS = 1
BASELINE_FILENAME = os.path.expanduser("~/.sgp_config_data.txt")
class _cmds():
"""container class for mapping between human readable names and the command values used by the sgp"""
Sgp30Cmd = namedtuple("Sgp30Cmd",["commands","replylen","waittime"])
IAQ_INIT=Sgp30Cmd([0x20, 0x03],0,10)
IAQ_MEASURE=Sgp30Cmd([0x20, 0x08],6,12)
GET_BASELINE=Sgp30Cmd([0x20, 0x15],6,120)
SET_BASELINE=Sgp30Cmd([0x20, 0x1e],0,10)
SET_HUMIDITY=Sgp30Cmd([0x20, 0x61],0,10)
IAQ_SELFTEST=Sgp30Cmd([0x20, 0x32],3,520)
GET_FEATURES=Sgp30Cmd([0x20, 0x2f],3,3)
GET_SERIAL=Sgp30Cmd([0x36, 0x82],9,10)
SGP30Cmd = namedtuple("SGP30Cmd", ["commands", "replylen", "waittime"])
IAQ_INIT = SGP30Cmd([0x20, 0x03], 0, 10)
IAQ_MEASURE = SGP30Cmd([0x20, 0x08], 6, 12)
GET_BASELINE = SGP30Cmd([0x20, 0x15], 6, 120)
SET_BASELINE = SGP30Cmd([0x20, 0x1e], 0, 10)
SET_HUMIDITY = SGP30Cmd([0x20, 0x61], 0, 10)
IAQ_SELFTEST = SGP30Cmd([0x20, 0x32], 3, 520)
GET_FEATURES = SGP30Cmd([0x20, 0x2f], 3, 3)
GET_SERIAL = SGP30Cmd([0x36, 0x82], 9, 10)
@classmethod
def new_set_baseline(cls,baseline_data):
def new_set_baseline(cls, baseline_data):
cmd = cls.SET_BASELINE
return cls.Sgp30Cmd(cmd.commands +baseline_data,cmd.replylen,cmd.waittime)
return cls.SGP30Cmd(cmd.commands + baseline_data, cmd.replylen, cmd.waittime)
class Sgp30():
def __init__(self,bus,device_address = 0x58, baseline_filename=BASELINE_FILENAME):
class SGP30():
def __init__(self, bus, device_address=0x58, baseline_filename=BASELINE_FILENAME):
self._bus = bus
self._device_addr = device_address
self._start_time = time()
self._last_save_time = time()
self._baseline_filename=baseline_filename
self._baseline_filename = baseline_filename
Sgp30Answer = namedtuple("Sgp30Answer",["data","raw","crc_ok"])
SGP30Answer = namedtuple("SGP30Answer", ["data", "raw", "crc_ok"])
def _raw_validate_crc(s,r):
a = list(zip(r[0::3],r[1::3]))
crc = r[2::3] == [Crc8().hash(i) for i in a ]
return(crc,a)
def _raw_validate_crc(s, r):
a = list(zip(r[0::3], r[1::3]))
crc = r[2::3] == [Crc8().hash(i) for i in a]
return(crc, a)
def read_write(self,cmd):
write = i2c_msg.write(self._device_addr,cmd.commands)
if cmd.replylen <= 0 :
self._bus.i2c_rdwr(write)
def read_write(self, cmd):
write = i2c_msg.write(self._device_addr, cmd.commands)
if cmd.replylen <= 0:
self._bus.i2c_rdwr(write)
else:
read = i2c_msg.read(self._device_addr,cmd.replylen)
read = i2c_msg.read(self._device_addr, cmd.replylen)
self._bus.i2c_rdwr(write)
sleep(cmd.waittime/1000.0)
self._bus.i2c_rdwr(read)
r = list(read)
crc_ok,a=self._raw_validate_crc(r)
answer = [i<<8 | j for i,j in a]
return self.Sgp30Answer(answer,r,crc_ok)
crc_ok, a = self._raw_validate_crc(r)
answer = [i << 8 | j for i, j in a]
return self.SGP30Answer(answer, r, crc_ok)
def store_baseline(self):
with open(self._baseline_filename,"w") as conf:
baseline=self.read_write(_cmds.GET_BASELINE)
with open(self._baseline_filename, "w") as conf:
baseline = self.read_write(_cmds.GET_BASELINE)
if baseline.crc_ok == True:
json.dump(baseline.raw,conf)
json.dump(baseline.raw, conf)
return True
else:
#print("Ignoring baseline due to invalid CRC")
@@ -70,14 +72,14 @@ class Sgp30():
def try_set_baseline(self):
try:
with open(self._baseline_filename,"r") as conf:
with open(self._baseline_filename, "r") as conf:
conf = json.load(conf)
except IOError:
pass
except ValueError:
pass
else:
crc,_ = self._raw_validate_crc(conf)
crc, _ = self._raw_validate_crc(conf)
if len(conf) == 6 and crc == True:
self.read_write(_cmds.new_set_baseline(conf))
return True
@@ -101,7 +103,7 @@ class Sgp30():
#print("Initializing SGP30")
self.read_write(_cmds.IAQ_INIT)
def i2c_geral_call(self):
def i2c_general_call(self):
"""This attempts to reset _ALL_ devices on the i2c buss
This command issues the i2c-general call RW command that should result
@@ -111,20 +113,21 @@ class Sgp30():
This will usually un-stick the SGP30, but might reset or otherwise
affect any device on the bus.
"""
self._bus.write_byte(0,0x06)
self._bus.write_byte(0, 0x06)
sleep(.1)
def main():
with SMBusWrapper(1) as bus:
sgp=Sgp30(bus,baseline_filename=BASELINE_FILENAME+".TESTING")
sgp = SGP30(bus, baseline_filename=BASELINE_FILENAME+".TESTING")
print("resetting all i2c devices")
sgp.i2c_geral_call()
sgp.i2c_general_call()
print(sgp.read_features())
print(sgp.read_serial())
sgp.init_sgp()
print(sgp.read_measurements())
bus.close()
if __name__ == "__main__":
main()

11
test.py Normal file
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@@ -0,0 +1,11 @@
from smbus2 import SMBusWrapper
from sgp30 import Sgp30
import time
with SMBusWrapper(1) as bus:
sgp=Sgp30(bus)
print("resetting all i2c devices")
sgp.i2c_geral_call()
print(sgp.read_features())
print(sgp.read_serial())
sgp.init_sgp()
print(sgp.read_measurements())