Hot house controller

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What Meccano is for mechanics is Arduino for electronics. The nice thing is that you can combine the two, mechanical actions triggered through electronics.

This first project is a topic which has a real need. It is to switch a heater on in a hot house I have in my garden. The technique is nothing fancy, a digital thermometer sensor and a relais that switches the heater within a temperature range. Extra is a humidity sensor, visibility is through a led display that shows alternatively the temperature and humidity. The processor is a Arduino Nano clone, the headers were not connected and which I soldered myself. (with YouTube assistance).

The small breadboards are quite usable with a nano, you can place them on it and can use the ports and voltage connectors quite easily. The humidity sensor is a DHT11 type, which is of sufficient precision for this purpose. The temperature sensor is also quite standard. it is placed outside the enclosure to have more accurate measurements. The heater is 2000 watt which I can switch using the relays.

The LED panels are nice. The characters you can display are a bit limited but sufficient for this purpose. I have extended the library a bit with settings for the decimal separator which I could not find elsewhere.

Programming the Arduino is actually easy. There are so many examples available that applications combining the examples is easy.

What needs to improve is making the connections work, I switched to single core copper of 0.8 mm, with some effort you can make DuPont connections with this type of wire alternatively you can also put them directly in the breadboard an advantages are that the connection is lower and you can create them in exact length.

I’m also practicing creating DuPont connections using a crimping tool to create your own connection cables. Not over complicated but you have to make them real precise to have good and stable connections, this is especially true when making a three or two fold connector. The shield really needs to click in place smoothly if not it is nor good. Female connectors are more difficult to make versus the male type.

Soldering also needs to improve which can only be achieved through practice. Soldering header pins to boards is well possible but needs more practice and perhaps a better soldering iron.

Arduino Nano.
Sensor.