The payload will include a meteorology package for atmospheric measurements. The below instruments have been purchased and are being incorporated into the instrument package.
The BME280 based sensor is from Adafruit. This new sensor has temperature, barometric pressure, and humidity functions. The unit works with both I2C and SPI. This is getting to be important, as conflicts with I2C addresses can be a factor with all of the instruments being added to the system.
For measuring barometric pressure, I selected the Adafruit BMP183 board.
The unit has the following features:
- measures barometric pressure and temperature
- low altitude noise of 0.25m
- fast conversion time
- SPI interface
- 3.3V regulator (so you can use it with 3-5V power)
- SPI level shifter (so you can use it with 3-5V logic).
Here is the link to their product page: BMP183
For temperature sensing, I selected the Adafruit MCP9808 board. Here is the vendor link: MCP9808
The sensor has the following features:
- Simple I2C control
- Up to 8 on a single I2C bus with adjustable address pins
- 0.25°C typical precision over -40°C to 125°C range (0.5°C guaranteed max from -20°C to 100°C)
- 0.0625°C resolution
- 2.7V to 5.5V power and logic voltage range
- Operating Current: 200 μA (typical)