Arduino Temperature Device

Running on a Pro Mini 5V. Is use in rooms to monitor the temperature.

Features

• Measuring the temperature
• Plotting the temperature on a display
• Writing high, low and current values on a display
• Auto scaling the graph
• Adjusting the measurment interval via button
• Writing measurement interval on a display
• Writing last used interval to EEPROM, reading on startup
• Sending the temperature to another arduino or raspi via nrf2401l
• Indicating sending success on an LED
• Running multiple functions in "parallel" with a Task class
• Setting various options
• Many more...

Images

Part List

• Arduino
  • I have used a Pro Mini 5V
  • a Nano was also working
  • and a Uno R3
• Tactile Button
  • but no resistor since I use the internal pull ups and reverse logic
• Indicator LED
• Resistor for LED, e.g. 680 Ohms to keep the current low
• OLED
  • I have used a generic SSD1306 based one with SPI
  • SH1106 based one with I2C was also working but then you are very tight on RAM
• NRF24L01 Transceiver
  • NRF24L01 5V to 3.3V adapter board, my Pro Mini has no native 3.3V output so I need one of these
  • 100nF capacitor added between 3.3V and GND on the NRF24L01 to stabelize voltage, was not working without
• Wires

Memory Usage

According to Arduino IDE 1.8.10

Sketch uses 25128 bytes (81%) of program storage space. Maximum is 30720 bytes. Global variables use 1630 bytes (79%) of dynamic memory, leaving 418 bytes for local variables. Maximum is 2048 bytes.

According to Visual Studio Code 1.43.1 with Platform IO Core 4.3.0b2 Home 3.1.1

RAM: [======== ] 81.1% (used 1660 bytes from 2048 bytes) Flash: [======== ] 81.8% (used 25114 bytes from 30720 bytes)

Contribution

Pull requests are welcome, but keep them focused on one feature, bugfix or other improvement.

Schematics

...also...

3D models

...guess what...