I have built two of the DIY open sprinkler kits (1.4u with 1.8.3 firmware), one works fine the other seems to work on all functions except it has a clock problem. When I reboot, it gets the proper time and when refresh from the browser I see it the seconds count up. When it gets to a full minute past the reboot time it resets to the same time over and over (in a loop) so it never advances through the day. The browser screens always shows the same time (within that minute).
What could be the problem?
This means the RTC is not advancing time. In light of my blog post yesterday (http://rayshobby.net/?p=5962) one thing to try is to adjust the position of the 32.768kHz crystal, and resolder its pins to make it as close as possible to the PCB. If this doesn’t work, there may be an issue with the crystal, and I can send you a replacement crystal if you email me your mailing address. Thanks.
Ok, thanks. I’ll try resoldering tonight and let you know if that corrects the problem. Wondering if I ground the case on the crystal (wrap wire tighly around it and then solder other end of wire to a close ground somewhere), if that would help…
Well, it’s not the crystal body that attracts noise, but it’s the trace between the crystal and the DS1307 needs to be surrounded by ground trace. You can even solder the crystal directly onto the lower left two pins of DS1307, to hopefully reduce the trace length.
So, I removed the crystal and soldered it to the lower left pins (verified correct with ohm meter). Unfortunately it has the same problem, it resets every minute to the same time, so I’ll send you an email with my address for replacement crystal.
I wanted to let you know that all is working well now, it was a bad DS1307. I would like all to know what fantastic support Ray has given, kudos for being so responsive. I am a proud owner of 2 of his systems and highly recommend them!