The PCB on the left shows the “~uino” board which has a rotary knob holds a 8×2 LCD and two LEDs. The Atmega 328P chip is located under the LCD. The back side has a 5V regulator and header position for the Air-data sensor (I2C) , the Wind sensors and the regular Arduino UART interface pins for a 5V FTDI programming / boot loader connection.
For more display area the 8×2 LCD can be replaced with a larger one (up to 4×20) and connected via ribbon so that the LCD can be mounted separate.
The push button/rotary knob operates the display and setup menu functions. The same AirData sensor as on the WiFi station is used.
The following items are currently displayed:
– Bus Voltage (volt)
– Density Altitude (feet)( used in aviation)
– Standard Altitude (feet) (based on Standard Atmosphere)
– Compensated Altitude (feet) (by entering current sea level pressure)
– Station Pressure “hg
– Humidity (%RH)
– Temperature (degF)
– Dew point (degF) (dry atmosphere)
– Temperature Dewpt. Spread (used in aviation)
– Wind Direction (deg from North)
– Wind Speed current (Mph) ( 1 second)
– Wind Average (10 minutes running average)
– Wind Gust ( last 10 minutes )
The two LEDs indicate alarm situations:
– Blue LED comes on when Temp <= 1deg C
– Red LED comes on when Vbus is < 11 or >15 volt
– Red LED comes on when Temp-Dewpt spread is <8 deg F
Wind data is captured and updated once a second, while Baro and Hyg data is done at 2 second interval to prevent self heating of the sensors. At first release all data is displayed in imperial units, there is however plenty program space left to implement metric readout as well, only about 35% of the program memory is used so far.
The housing shown below I machined with a CNC router from a 3/4 thick Walnut plank. Hardwood flooring makes for cheap and readily available machining stock and the finished cases look really nice. A certain amount of dust is involved in the making of it however.
All source files for hardware, software and housing can be downloaded from GIThub here.
If you have access to a CNC machine that reads g-code, most do, you can probably cut the case with the .ngc file provided.
If there is interest I will build a bunch and have then up for sale.
Send me a note if interested.