CW25-TIM

There is a limitation for my GPS clock. It needs clear view of the sky in order to get accurate time. I can get only 2 satellites if I put antenna close to window. So, I have to put the antenna outside my window to get more than 3 satellites.
Just now, I have found CW25-TIM from NavSync. From a note in the website, it reports that the CW25-TIM can get 9 satellites in a room without window!. Very impressive!

SemiconductorStore is selling it at USD64. I am thinking about using this GPS module for my GPS clock so the clock will be selfcontained, no need to put antenna outside building.
After some searches, I found that CW12-TIM is a ready-to-use GPS module that uses CW25-TIM inside. So, my target is now CW12-TIM.

My GPS Clock is up and running

With the help of WDT, My GPS Clock is now running nicely. I don't know its exact accuracy. After comparing my GPS Clock time with SymmTime time, I can only say that my clock is very accurate. I use PIC16F877A to control the clock.


I use PPS (Pulse Per Second) to drive my clock so ,theroticaly , the clock should be very accurate. The PPS accuracy from the Lassen iQ GPS module is about 50ns (when position fixes or SV>2).
Next step, I will add sound of the second 'Tick' for accurately setting my watches. Also, I think that telling time with 7-Segment display should be more accurate than the LCD.