Building an APRS Weather Station for Under $300 APRS Wx station presentation by Chris, W8CWG, Mound Amateur Radio Association 3 Dec 2014

Hardware Hardware Requirements – Weather Station - $112 w/shipping – Raspberry Pi B+ - $60 (inc. pwr supply and 4Gb memory chip) – 8 to 32Gb Micro SD (optional for extra memory) – TNC-Pi - $69 w/shipping – Cables/adapters - $24 – Keyboard - $8 – Mouse - $6

Software Software Requirements (ALL FREE!) – Raspbian Linux (Debian “Wheezy” distribution) – Python versions 2.5, 2.6, or 2.7.x – Current Oracle Java runtime – Java librxtx-java package – Weewx ( – YAAC (

Software (cont.) Optional software products – Apache2 web server Needed if you want to publish weather charts over the Internet outside your home network – AX25 tools and apps

Hardware You have to have a weather station

Hardware You have to have a Raspberry Pi B+

Hardware You have to have a KISS TNC (this is a TNC-Pi)

Hardware You have to have a radio

Hardware Then assorted cables – HDMI to VGA Converter (not adapter) – Cable interface between radio and TNC – Power supply – USB cable between R-Pi and Wx station A keyboard and a mouse Monitor (optional if you use an A/B switch)

Hardware You must modify for Icom HT PTT configuration YMMV Requires a 33K ohm resistor between Mic and Mic Gnd

Hardware Modified for Icom HT PTT

Assembled Base Station The TNC-Pi mounts over top the R-Pi via the GPIO pin plug

Assembled Base Station The completed APRS station

Assembled Base Station Raspbian Linux main screen

Assembled Base Station YAAC Screen

Assembled Base Station YAAC Configure

Assembled Base Station

Lessons Learned The R-Pi and WxWise station are not shielded against RF – Added a number of ferrites to the various lines – Ultimately moved the antenna about 5 feet away – Consider installing boards in grounded metal box YAAC uses a large amount of memory – Solution is to set logging either off or at minimums Reduced the amount of Tx events – Needed to conserve battery power on the V82

Thanks for Watching! Building an APRS Weather Station For Under $300 Questions?