Latest Arduino Project

It has been quite a long time since I last had a tinker with an Arduino project. The last one was a weather station with digital readout. That never reached its final stage. All was going well until the day I updated the Arduino IDE (the program used to program an Arduino). The update went badly wrong. It kept reporting errors and wouldn't recognise the instruction I had written previously.

Recently I decided to delete all the old IDE files and install the latest version from scratch. Then a new weather station project on the Instructables site caught my interest. It uses a 3.5 inch full colour TFT display to show the readings in graphical form. The display used is designed to fit on and use with an Arduino Mega. It has a resolution of 480 x 320 pixels.

I found one for sale on eBay direct from China for less than £8 which included postage. After 10 days it arrived. I also had to purchase the tiny unit which actually measures temperature, air pressure and works out the relative humidity. I already had an Arduino Mega.

The sensor module, sensor is the tiny metal box top right


As always there were other 'libraries' of instructions to install which enable access to the sensor and TFT display. It took a while to find the TFT library files but I discovered a set on the Rinky-Dink Electronics site. They installed and worked perfectly.

Once the program was installed and tested I made some alterations to the original. As well as the graph the most recent readings are now shown numerically just above the X axis. Also I had to alter the range of values on the Y axis to suit the possible range of local readings. At first I thought the pressure readings seemed to be far too high but checking on the Met Office site showed it to be within 1mbar. More accurate than my commercial weather station!



The display shows up to 36 hours of data (one new reading every 6 minutes) which makes it possible to see weather trends. The above was taken after a 26 hr test run with the unit in the conservatory. When the screen is full the graphs are scrolled from right to left by one pixel with each new reading. Maybe I will change the timing to every 8 minutes so as to display the trend over 48hrs.

Obviously to be of any use the detector needs to be outdoors in a suitable container. Ideally, once I've finished tinkering, I  will have a go at designing and 3D printing a suitable box to hold the Mega and TFT display.

I am so delighted with the possibilities of this colour display I have ordered another one  to experiment with. Screen refresh is slowish so not suitable for displaying video for example.