test.py has funny ideas of seconds

[bzfbd]

I set the time and then uncommented that function call along with the print(t) and tried to read a few times but the results were anything but reliable. Has anyone seen this before?

python3.8 test.py

15/9/21 16:46:25 Wed
87.80000000000001 F / 31.0 C

(1 second real time, clock jumps 8s forward)

15/9/21 16:46:33 Wed
87.80000000000001 F / 31.0 C 15/9/21 16:46:34 Wed
87.80000000000001 F / 31.0 C 15/9/21 16:46:35 Wed
87.80000000000001 F / 31.0 C 15/9/21 16:46:37 Wed
87.80000000000001 F / 31.0 C 15/9/21 16:46:38 Wed
87.80000000000001 F / 31.0 C 15/9/21 16:46:39 Wed
87.80000000000001 F / 31.0 C 15/9/21 16:46:41 Wed
87.80000000000001 F / 31.0 C

python3.8 test.py

15/9/21 16:46:73 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:80 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:81 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:83 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:84 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:85 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:87 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:88 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:46:89 Wed

(whatever it read there isn't a second...; last I checked they wrapped at 60)

87.80000000000001 F / 31.0 C 15/9/21 16:47:1 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:2 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:3 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:5 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:6 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:8 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:9 Wed 87.80000000000001 F / 31.0 C

(and another jump)

15/9/21 16:47:16 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:17 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:19 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:20 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:21 Wed 87.80000000000001 F / 31.0 C 15/9/21 16:47:23 Wed

[kristerbrus]

Got the same weird behaviour from test.py. The RTC stores time/date values as BCD.

For every value pulled from the RTC, you have to convert the BCD encoded value to binary. For example:

seconds = bcd2bin(bus.read_byte_data(0x68, 0) & 0x7f)

with the following function:

def bcd2bin(value):
    return value - 6 * (value >> 4)

Hope it helps.

[sbcshop]

Hi,

Greetings of the day !

Thanks for mentioning the issue, We have fixed the above issue in our latest commit.

[sobrinho]

@sbcshop then the issue can be closed :)

[emanuelstanciu]

Hi everyone,

I am getting the following when trying test.py with Python 3.8.16 through pyenv:

❯ python test.py
Traceback (most recent call last):
  File "test.py", line 55, in <module>
    t[0] = t[0]&0x7F  #sec
TypeError: 'int' object is not subscriptable
❯ python --version
Python 3.8.16

Any pointer will be greatly appreciated.

Thanks, Emanuel