My idea is to create a portable watch with the following features:
- show time and date
- display internal clock temperature and air pressure (and altitude)
——Get RF (433MHz) data based on temperature and humidity of the attanny85 small device
- Save data on temperature, humidity, barometric pressure and altitude for the last 24 hours and the last 60 minutes
- a graph showing the temperature, humidity, barometric pressure and altitude for the last 24 hours and the last 60 minutes
Step 1: Components and connections
Watch component
Arduino nano
Watch module
RF module 433 mhz
BMP180 barometer
128X64 dot matrix display of OLED SPI
Battery lithium ion (from mp3 player)
2 x tact switch
On/off switch
Thermometer component
Attiny85 micro USB board digispark
Thermometer DHT11 module
The transceiver is 433MHz.
Step 2: Compress the table
The elements of the watch are tightly attached and fixed and placed in a fiberglass box.
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Step 3: Wireless Thermometer
The board power is 2 x 18650, giving a 7.4v to board and RF module. Will the power be much smaller? For example, a 2x flat battery.
I am using a normal antenna ~ 18.5 cm instead of DHT 11, for more precise values ​​you can use dht22. You can use other sensors that can be connected to digispark (note that the attny85 sketch must be less than 6KB!)
The sketch is very simple, based on the Manchester.h library (the VirtualWire library is too complicated for attuny85)
To guide the sketch to digispark attiny85 you need a special Arduino IDE (Digispark-Arduino-1.0.4)
Step 4: Watch sketch
The sketch is still original and needs to be modified, but the work is not wrong.
Press a button to see the changing mode.
Temperature, humidity, barometric pressure and altitude data are stored in the EEPROM every minute (including the last hour of 60 units), hourly (including the last day of 24 units).
The pattern of patterns is from right to left (new to old data). The size of the T24 mode can be enlarged by pressing the B button.
Step 5: Conclusion
This project has not been completed and still needs to be revised. The RF connection distance is 45m. How to increase this distance? The power saving must be in the sliding mode and the wake-up button must be activated. How to achieve it?
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