This is a little application for the wonderful bit of hardware from Seeed, the Wio Terminal. Using a Grove temperature sensor, this prints out a line graph of the ambient temperature over time. It does this with a non-blocking delay using Arduino's millis() function.
To use, acquire both a Wio Terminal and a Grove temperature sensor, plug the temperature sensor in to the right hand Grove port (left hand port is I2C specific), load this project in PlatformIO's extension for Visual Studio Code and enjoy! You can turn the display on and off by pressing in the joystick.
Note that I made this during a summer heatwave, so the scale is set at a floor of 15C. You can adjust this by setting the value of .based_on to whatever you'd like. It is set to take a reading every ten minutes and save fifty readings -- you can adjust this by setting period and max_size.
Things to do or fix:
The non-blocking delay unfortunately means the screen won't actually draw anything until the first sample is taken at the end of the periodicity -- e.g., if you have the timing set for ten minutes, you won't see anything drawn until that first ten minutes has passed.Done! Push the top leftmost button (Button C) to take and plot an immediate sample. Note that the first time you do this you will have to press it twice.- Wio Terminal has an SD card slot; maybe at the same time that the graph is drawn also write to the card with the elapsed time and temperature.
- There's also built-in Wifi (man, what does the Terminal not have? Seriously, this is a great little device) so perhaps use an NTP client to make proper timestamps for the SD log.
- The Wio Terminal supports CircuitPython(!!!!!) so maybe reimplement this in CircuitPython sometime.
An Arduino IDE specific version.Done! In the arduino-ide directory.
This uses a fair chunk of sample code for the temperature sensor and the line graph - thanks to Seeed for the easy-to-use demos. Everything written by me is licensed under the MIT License. Please see LICENSE for details.