A low-power, low-cost integrated weather logger suitable developed as part of a research project on micro-scale weather processes in the Aizu basin.
Version 1 is an Atmega328p based data logger, connected to an external board containing, one pressure (BMP180), one humidity (HIH-6031-001) and two temperature sensors (TMP102, LM92). The Atmega is clocked internally using a RC circuit. A 32.678KHz crystal is connected the TOSC1(2) pins to provide a simple Real Time Clock. For logging, a microSD card is used. The unit comes with a holder for a 3.7V cell battery, for limited period use such as in a tethered balloon sounding. Two switches (slider and push button), with associated debouncing hardware, can be used for setting the time, and for sleep. The schematic is available in the doc folder.
Version 2 will include a single band GNSS reciever for GNSS based water-vapor measurements and possibly a 2.4GHz radio for networking.
The GNSS based water-vapour logger
This is being developed. Documentation during this development stage can be found at http://climdyn.u-aizu.ac.jp/redmine/projects/low-cost-gnss-applications/wiki and http://climdyn.u-aizu.ac.jp/redmine/projects/opentws/wiki The latter wiki page also hosts the hardware design schematic