Weather Equipment
Main Weather Station (CT2JKO-11)
The APRS weather station is a kit, called T238+ and sold by TAPR (Tucson Amateur Packet Radio), which consists on a small weather station with screen, 4 button keypad and modem. No sensors are included. The protocol is 1-wire, allowing to connect several sensors such as temperature, humidity, barometric pressure, anemometer, wind direction and rain gauge. I only installed temperature, humidity and pressure sensors as the station location (on my apartment's window) doesn't allow the sensors to acquire correct rain and wind measurements. The outside sensor consists on humidity and temperature sensors. The humidity sensor was purchased from AAG Electronica and I added a 1-wire temperature chip (DS18S20) to it. The barometric pressure sensor is another kit by TAPR. The only thing missing was a transceiver - I choosed an Alinco DJ-V17 portable radio, which is enough for the weather informations to reach an APRS station connected to the internet (Digipeater). This project took some months (February 2009 to August 2009) to finish and it was not very cheap but I'm happy the station is finally working.
Exterior Sensors and Antenna:
Specifications:
Weather Station Model: TAPR T-238 + Kit (Assembled by CT2JKO)
APRS Beacon Interval: 5 minutes (averaged weather informations)
Antenna: 1/4 Wavelenght Ground Plane (Homemade)
Transceiver: Alinco DJ-V17
RF Power: 5W
Temperature Sensor: Dallas DS18S20
Temperature Sensor Range: from -55 ºC to +125 ºC
Temperature Sensor Precision: 0.1 ºC
Homemade Humidity and Temperature Sensor Shield:
Temperature Sensor Accuracy: +/- 0.5 ºC (from -10 ºC to +85 ºC)
Humidity Board: AAG TAI8540D
Humidity Sensor: Honeywell HIH-3610-A
Humidity Sensor Range: 0-100 %
Humidity Sensor Precision: 1 %
Humidity Sensor Response Time: 15 s
Humidity Sensor Accuracy: +/- 2 % (non-condensing @ 25 ºC)
Barometric Pressure Board: TAPR X1W-1 Kit (Assembled by CT2JKO)
Barometric Pressure Sensor: Motorola MPX4115AP
Barometric Pressure Range: any 200 mb range, typically 870 mb ~ 1070 mb
Barometric Pressure Precision: 0.1 mbar
Barometric Pressure Response Time: 1 ms
Barometric Pressure Sensor Accuracy: ±1.5 % (0° to 85 °C)
Detail on the Weather Station's Display:
Alinco DJ-V17E:
Homemade 1/4 Wavelenght Groundplane Antenna for 144.800MHz:
Inside Look (rollover image):
CT2JKO-11's Classic Style:
Most of the information below was taken from the official T238+ webpage: http://www.beals5.com/wx/
Weather Station Documents and Data Sheets:
X1W-1 (Barometric Pressure Board) Assembly Manual
Software:
T238+ Firmware Update Program (Instructions: If you are updating software using the monitor, hook up your computers serial port to the Computer (NOT debug) port on the weather station. Apply power to the weather station with both the up and down buttons pressed simultaneously. The weather station will come up in monitor mode which currently does NOT initialize the display (I hope to fix this soon). Have both the MON08.EXE and latest .S19 files in the current directory. The .s19 file is above in the format x-xx-x.s19 where the x's are the firmware version number. At the DOS command prompt, enter MON08, the file, and the COMM port number. For example "MON08 1-15-3.S19 1" (assuming Rev 1.15.3 firmware and COM1 for your serial port. The PC monitor will start up communication with the 6808 monitor and after comfirming your intentions, will download the new code, perform a soft reset, then run the new app.)
Software Versions:
Accessories and Classic Weather Equipment:
- Digital Thermometer (0.5ºC precision)
- Thermo/Higro Weather Station: Oregon Scientific BAR 112HG + Wireless Sensor THERMO-HIGRO
- Homebrew Psychrometer (2 Mercury Thermometers used to measure Relative Humidity)
- Aneroid Barometer
- Sealed Box for Instrument Calibration
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