9292f4e17e
I dont know if it is a limitation of i2cwr or the sgp but it dosnt seem to clock-strech but rahter just not present any data if the messure ment is not done, so timing is important. The test should now fail if data is read to fast
63 lines
1.7 KiB
Python
63 lines
1.7 KiB
Python
from smbus2 import i2c_msg
|
|
from collections import namedtuple
|
|
|
|
from .context import sgp30
|
|
from time import time
|
|
|
|
I2CAnswers= namedtuple("I2CAnswers",["answer","min_delay"])
|
|
I2A = I2CAnswers
|
|
def add_crc(l):
|
|
return l + [sgp30.Crc8().hash(l)]
|
|
|
|
answers = {
|
|
(0x36, 0x82): I2A(add_crc([0,0]),.4), #GET_SERIAL
|
|
(0x20, 0x15): I2A(add_crc([0,0]), 1), #GET_FEATURES
|
|
(0x20, 0x03): I2A(None, 2), #IAQ_INIT
|
|
(0x20, 0x08): I2A([1, 144, 76, 0, 6, 39], 10), #IAQ_MEASURE
|
|
(0x20, 0x32): I2A(add_crc([0xD4,0x00]), 200), #IAQ_SELFTEST
|
|
(0x20, 0x15): I2A([133, 152, 85, 138, 32, 202], 10), #GET_BASELINE
|
|
(0x20, 0x1e): I2A(None, 10) #SET_BASELINE
|
|
}
|
|
|
|
class MockSMBus:
|
|
def __init__(s,break_crc=False):
|
|
s.status=None
|
|
s.last=None
|
|
s.addr=None
|
|
s._break_crc=break_crc
|
|
s._deadline=time()
|
|
|
|
def _set_deadline(s, t):
|
|
s._deadline=time() + t/1000.
|
|
|
|
def i2c_rdwr(s,*msgs):
|
|
for m in msgs:
|
|
if time() < s._deadline:
|
|
raise IOError("To fast buss-access, device not ready")
|
|
if m.flags == 1:
|
|
s._process_read(m)
|
|
else:
|
|
s._process_write(m)
|
|
|
|
def write_byte(s,addr,data):
|
|
s.status=None
|
|
s.addr=addr
|
|
s.last=data
|
|
|
|
def _process_read(s,msg):
|
|
if s.status == None:
|
|
raise AssertionError("Tried to read before write")
|
|
for i in range(len(s.status)):
|
|
msg.buf[i]=chr(s.status[i])
|
|
if s._break_crc and i%3 == 2:
|
|
msg.buf[i]=chr(s.status[i]^42)
|
|
s.status=None
|
|
|
|
|
|
def _process_write(s,msg):
|
|
a = answers[tuple(msg)[0:2]]
|
|
s._set_deadline(a.min_delay)
|
|
s.status = a.answer
|
|
s.last=msg
|
|
|