| hektek | Posted: 19 May 2021, 06:19 PM |
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 Member Posts: 1 Joined: 19-May 21 |
I have a slight problem. Can you suggest where to look for a solution please. On powering up the 1/100 digits scroll for a few minutes, then the date and time shows. Then after a period, a few seconds or sometimes a few minutes they disappear. I have changed to a puk type antenna and the LED on the GPS flashes as does the GPS fix led on the PCB. The Time zone leds are on when the time is showing but I have yet to see the colons flash. I did a small 20sec video, the link of which is below. It will have to be downloaded and opened in a viewer. It says 'MP4 files are supported but something went wrong'. Then an OPEN tab shows. I opened in VLC and VLC worked for me. Any ideas appreciated, on the clock, not the dropbox MP4 problem :-) regards Phil https://www.dropbox.com/preview/clock.mp4 ------------- |
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| mit | Posted: 20 May 2021, 09:54 AM |
 yeah whatever Admin Posts: 538 Joined: 4-May 16 |
I can't download the video, I think you might need to make the permissions public, or find another way of sharing it. I'm very keen to see it, however, since I've not encountered anything like what you've described. The GPS fix is blinking - that means the GPS is fine and has a fix. The date and time is shown (if briefly) - that means serial communication between the GPS and ATtiny is OK. QUOTE
Since I can't yet watch the video, could you describe what happens when they disappear? Does the display go blank, or show something else?Then after a period, a few seconds or sometimes a few minutes they disappear. ------------- |
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| mit | Posted: 24 Jun 2021, 10:49 AM |
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yeah whatever Admin Posts: 538 Joined: 4-May 16 |
In case anyone else has this problem, here was the resolution: The symptom was that as soon as a GPS fix was acquired, the clock would start rebooting. This appeared as the display changing back to all hyphens and counting for almost a second, then resetting again. The cause was that somehow the PPS signal was coupling to the reset signal of the ATtiny chip. I first suggested shorting the reset pin to VCC, to act as a stronger pullup, and see if that fixed it, which it apparently did not. (The internal pullup on the ATtiny's reset pin is quite weak.) After that, the display in front of the ATtiny chip was removed in order to clean up the solder joints. The culprit may have been some flux residue, or it may have been a very small whisker of solder, but in the end the clock started working properly. ------------- |
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