async def do_usec(minutes):
global gps
tick = Message()
print('Setting up GPS.')
await us_setup(tick)
print('Waiting for time data.')
await gps.ready()
max_us = 0
min_us = 0
sd = 0
nsamples = 0
count = 0
terminate = Event()
asyncio.create_task(killer(terminate, minutes))
while not terminate.is_set():
await tick
usecs = tick.value()
tick.clear()
err = 1000000 - usecs
count += 1
print('Timing discrepancy is {:4d}μs {}'.format(
err, '(skipped)' if count < 3 else ''))
if count < 3: # Discard 1st two samples from statistics
continue # as these can be unrepresentative
max_us = max(max_us, err)
min_us = min(min_us, err)
sd += err * err
nsamples += 1
# SD: apply Bessel's correction for infinite population
sd = int(math.sqrt(sd / (nsamples - 1)))
print(
'Timing discrepancy is: {:5d}μs max {:5d}μs min. Standard deviation {:4d}μs'
.format(max_us, min_us, sd))
async def main():
event = Event()
asyncio.create_task(waiter(event))
await asyncio.sleep(2)
print('Setting event')
event.set()
await asyncio.sleep(1)
# Caller can check if event has been cleared
print('Event is {}'.format('set' if event.is_set() else 'clear'))
async def do_time(minutes):
global gps
fstr = '{}ms Time: {:02d}:{:02d}:{:02d}:{:06d}'
print('Setting up GPS.')
gps = await setup()
print('Waiting for time data.')
await gps.ready()
print('Setting RTC.')
await gps.set_rtc()
print('RTC is set.')
terminate = Event()
asyncio.create_task(killer(terminate, minutes))
while not terminate.is_set():
await asyncio.sleep(1)
# In a precision app, get the time list without allocation:
t = gps.get_t_split()
print(fstr.format(gps.get_ms(), t[0], t[1], t[2], t[3]))