ebay DS3231 timing quirk
Peter Jakacki
Posts: 10,193
I've been using these cheap DS3231 RTC modules from ebay and they have been really great. Not only are they a neat little RTC module complete with battery and using the accurate temperature-compensated DS3231, but they are also cheap at around $2 each.
So I said they are great but there is a snag as I deduce that either these are fake chips or seconds or something other than the genuine article as the chip alone is over $5 in quantity from Maxim distributors. The snag is that they "drop" a chunk of time every month or so. I just checked on a unit before via Bluetooth and it is exactly 20 minutes slow, but not slow because it hasn't been keeping time as otherwise it has been fine, but like it's dropped 20 minutes all of a sudden. I had this problem before where I think it dropped 10 minutes one time and another time it was the wrong date but right time. I can't be sure exactly what was what now but although infrequently, I know it is playing up. A reference unit I have on the bench seems to be fine but the temperature here is fairly stable too.
Anyone been using these modules and noticed these kinds of quirks etc?
(this thread is more about identifying a general quirk rather than "caveat emptor")
BTW, this could be general discussion material but it's all Propeller related to me
So I said they are great but there is a snag as I deduce that either these are fake chips or seconds or something other than the genuine article as the chip alone is over $5 in quantity from Maxim distributors. The snag is that they "drop" a chunk of time every month or so. I just checked on a unit before via Bluetooth and it is exactly 20 minutes slow, but not slow because it hasn't been keeping time as otherwise it has been fine, but like it's dropped 20 minutes all of a sudden. I had this problem before where I think it dropped 10 minutes one time and another time it was the wrong date but right time. I can't be sure exactly what was what now but although infrequently, I know it is playing up. A reference unit I have on the bench seems to be fine but the temperature here is fairly stable too.
Anyone been using these modules and noticed these kinds of quirks etc?
(this thread is more about identifying a general quirk rather than "caveat emptor")
BTW, this could be general discussion material but it's all Propeller related to me
Comments
http://tronixstuff.com/2013/05/16/the-max7219-led-display-controller-real-or-fake/
Great article. Matches my experience: that most clones work but it's still a Smile-shoot and an ethical issue.
Also worth noting is that China was blessed with many things (like much of the world's neodymium) but copper wasn't one of them. Inexpensive Chinese resistors, transistors, and ICs all use some form of plated annealed steel for their leads. My diagonal cutters are magnetized. Cutting steel leads is a PITA! Heat dissipation also suffers.
more like.