def _update(self):
t = time.ticks_ms()
#if self.suspend_start is not None \
# and time.ticks_diff(t,self.suspend_start) <= self.suspend_time:
# print("Bus access suspended.")
if self.suspend_start is None \
or time.ticks_diff(t,self.suspend_start) > self.suspend_time:
self.suspend_start = None # done waiting
try:
if self.msgq is not None:
self.pin.writeto(self.addr, self.msgq)
self.msgq = None
s = self.pin.readfrom(self.addr,self.BUFFER_SIZE)
except:
print("Trouble accessing i2c.")
else:
if s[0]==255 and s[1]==255: # illegal read
print("Got garbage, waiting 1s before accessing bus again.")
print("data:", s)
self.suspend_time=1000 # take a break
self.suspend_start = time.ticks_ms();
else:
count = s[0]*256+s[1]
if self.count != count:
l = s[2];
self.suspend_time = s[3];
# scale timer
if self.suspend_time & 128:
self.suspend_time = (self.suspend_time & 127) * 100
if self.suspend_time>5000: # should not happen
print("Garbage time -> waiting 1s before accessing bus again.")
print("data:",s)
self.suspend_time=1000
if self.suspend_time > 0:
self.suspend_start = time.ticks_ms();
print("Bus suspend for",self.suspend_time,"ms requested.")
if l <= self.BUFFER_SIZE: # discard if too big
self.count = count
self.current_value = s[4:4+l]
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