Once a year, Gateshead Library puts on some STEM event – an eDay or a Raspberry Pi Jam, or something like that. I have been exhibiting since about 2014. In September 2019 it was a Raspberry Pi Jam and I decided to show off my model house, fitted with lights, a temperature/humidity sensor and a servo motor controlled by an Arduino and a Raspberry Pi. I thought that this exhibit would also give me an idea of how the public responds to what I have to show.
I was worried that others might not think the house is all that interesting. But, I have to admit, the house is quite eye catching and quite a few people came over to look at the house.
At first I kept the house closed up, i.e. I didn’t take the roof off to show all the wiring. I didn’t think it was really in a state to show because it was all blue tac’ed together and not in a neat state. However, to my surprise, people found the guts of it all quite interesting too.
The inner workings of the house consisted of an Arduino mico pro connected to a Raspberry Pi. The Arduino switches the fairy light strip on via a 2N222 transistor (i.e. on the green strip board to the right of the picture). There is also a single LED (slightly hidden by the red and blue wires in the front left), a servo motor and a DHT11 temperature/humidity sensor connected to the Arduino. The Arduino, single LED and sensor gets its power from the USB port but the rest get their power from the 9V battery via a little power unit on the breadboard.
A small Java program is used to display a simple dashboard of squares on a 7″ touch screen. Each square would be a switch to switch something on or off or to display the information published by a sensor.
All code is being made available on GitHub: https://github.com/jsteyn/Engineers. (Don’t worry, I’ll change the passwords on the final products)
I’m glad I did this exhibit as I learnt a few things.
- If possible, people will touch and disassemble.
- Anticipate touching and disassembling and either prevent it or make the model sturdy enough to cope with it.
- People found the inside and outside intriguing so it can all be shown off.
- There is a slight delay when switching things on via the touch screen. This causes one to press the buttons several times which in turn would switch the button between on/off states. A solution needs to be found to prevent this from happening.