Temperature sensors with display and alerting for marine aquarium


This article is still in progress and not completed yet...

In marine fishkeeping the water temperature belongs to the important and easy to monitor water parameters that can be monitored electronically straightforward. The temperature is strongly dependent on the room temperature and influenced by equipment like UV-C clearer and lighting in particular if the LEDs are sitting close to the water surface. Inappropriate water temperature, meaning out of the rage of 23 to 28 °C can lead to damage or even death of the fishes and the corals.

In order to monitor the temperature I build a small device with two temperature sensors that will constantly monitor the temperature at two different places in the aquarium. You don’t need your mobile all the time, the values can be checked at the display of the device and if the temperature leaves a defined range of 24-27 °C you get notified. The device has got a physical notification. That means a buzzer starts beeping and you can pause the notification by pressing the snooze button for defined period of time. The device is communicating to a mqtt broker of the houseautomation system as well, so that you get a push message on your mobile when you are on the go.

Inside view of the temparature sensor device.
Inside view of the temparature sensor device.

Now lets have a look at the list of part I used:

11 x D1 Mini D1 Mini V3 NodeMCU ESP8266EXAmazon-Link
21 x OLED display shield I2C SSD1306Amazon-Link
32 x Temperature Sensor - 3M Kabel DS18B20Amazon-Link
41 x Box, Electronic Enclosure, Waterproof (89x59x35mm)Amazon-Link
51 x Round Acryl Sheets, 2 Zoll/ 5 cmAmazon-Link
61 x UHU 45440 SuperglueAmazon-Link
71 x M12 Cable FittingAmazon-Link
81 x KY-012 Piezo Buzzer AlarmAmazon-Link
91 x Resistor 470Ω from Resistor KitAmazon-Link
101 x Resistor 10kΩ from Resistor KitAmazon-Link
111 x PCB 7x3cm shortened from Universal Board KitAmazon-Link
123 x Screw Terminals from Universal Board KitAmazon-Link
131 x Tactile Push Button 9,5mm from Button KitAmazon-Link
141 x Micro Cable Electronics Male/Female ConnectorAmazon-Link
151 x Universal Power Supply 5VAmazon-Link

I used the tool Fritzing to desing the circuite. Afterwards I cut out a board and soldered all parts on it so that it fits into the small case.

Electronic circuite of the temparature sensor device.
Electronic circuite of the temparature sensor device.

Source Code

The source code of the PlatformIO project can be found on Github: