Electronics

Raspberry Pi Temp Sensor Part 1

Over the last few years I have been teaching a class called Mechatronics that combines together engineering and robotics with a goal for students to build real world technology to solve a problem. In building student learning for open ended tasks, I needed a project that could combine many skills together. I had previously used Arduino’s to enable a programmable device with I/O but I was happy bring in other technologies. I had also been coding more and more with Swift and making Apps with Xcode. As my students had also begun their journey with App Development in other classes, I thought it would be a great opportunity to leverage this knowledge and see how I could show live data from a temperature sensor in an App. So this lead me to the path of using a Raspberry Pi to become the hub of the project as I could basically build a database and web server that stored and shared data collected from a temperature sensor. This data could then be shown via an iOS app.

Essentially this series of guides will cover:

  • Setting up a DS18B20 temperature sensor
  • Writing a Python script to read the sensor
  • Setup of LAMP. Linux, Apache, MySQL & PHP for the webserver
  • Writing the values from the temp sensor to the MySQL database
  • Writing PHP scripts to access the MySQL database from a web browser
  • Outputting the results as JSON for a mobile app to read.
  • An simple iOS app to read our temp sensor values and display them