See the section on option record_generation.
-Running weewx on a Raspberry Pi has become - very popular. You'll have to look elsewhere for instructions on setting up - your RPi, but there are a few very common problems with - setting them up.
-You must run NTP on your RPi, and you must make sure it - starts and updates the time before weewx - runs.
-The reason is that the RPi does not have an onboard clock. If you lose - power and, say, an hour later it comes back, your RPi will simply pick up - where it left off — one hour behind. The symptom that something is amiss - is that everything will appear to be running normally, but your webpage - will not get updated (at least, until the length of the power failure has - elapsed). - - Here's one user's nice analysis of the problem.
-What this means is that it is not enough to simply run the - weewx - daemon. You need some way of delaying its start until NTP is not only up - and running, but has contacted a time server and corrected the RPi's - clock.
-Several users are working on a solution to this problem. Perhaps you'll - be the one to figure it out?!
-The SD card supplied with most RPis seems to be of very low quality. Make sure - you use a good, Class 10 card. User William Phelps reports, "You can usually spot - a failing card by watching the kernel I/O wait time. Once the card starts to go, the - I/O wait time will increase significantly."
-Many Raspbian versions of Debian do not seem to include an FTP client. You may have - to install this if you plan on using FTP.
--sudo apt-get install ftp --
A lot of problems with the RPi seem to center around - inadequate power supplies. Many weather stations can - demand a lot of current through their USB connection. - Make sure your RPi can supply it, either by getting a good - power supply (I use - a Innogear - 1.5 A supply, which costs all of $5.50 from - Amazon), or, alternatively, by using a powered USB hub.
- -The RPi is astonishingly powerful for its size, but it does have its limitations. - If you plan on running a webserver on it, perhaps to serve your home, then use a - lightweight one, such as lighttpd - or nginx. Apache works, but it uses far more - memory. In my tests:
-| Webserver | VIRT | RES | -
| Apache | 222 Mb | 3 Mb | -
| lighttpd | 7 Mb | 2 Mb | -
| nginx | 11 Mb | 1.7 Mb | -
+ See the weewx wiki for up-to-date information on Running + weewx on a Raspberry Pi. +
+ +The Fine Offset series weather stations and their derivatives are a fine value and can be made to work reasonably reliably, but they have one