Summary of A Digital Thermometer Hygrometer With Analog Displays
This project creates a retro-style digital thermometer and hygrometer using an SHT21 sensor to measure temperature and humidity. Instead of a standard digital display, the readings are shown via two servos acting as needles on analog gauges. The setup connects the sensor to an ATMega328p microcontroller board via ribbon cable, with the sensor positioned at a distance to prevent interference from the MCU's heat.
Parts used in the Digital Thermometer Hygrometer With Analog Displays:
- SHT21 Temperature Humidity Sensor
- ATMega328p Microcontroller Board
- Two Servo Motors
- Sensor Breakout Board
- Ribbon Cable
It seems that you can’t visit to a microcontroller website without seeing a digital thermometer/hygrometer build of some kind. After all, it is pretty easy to build and at the same time quite useful as well. In this post, I will show you yet another thermometer/hygrometer build. But instead of using an LCD or 7 segment display for the output, I decided to go retro, using two “needles” to display the temperature and humidity readings instead.
And to make the project more fun, I did not use analog meters for the output but chose to use two servos instead. The temperature humidity sensor I used is SHT21 from Sensirion, the same sensor I used in my temperature logging project before. In that project, the temperature and humidity readings were sent over the network and displayed on my web server (you can see the current readings in my lab here)
The pictures below show how everything was put together. The circuit itself is as simple as it gets. SHT21 is mounted on a breakout board and connected to the ATMega328p board via ribbon cable. The sensor is placed at some distance away from the MCU board so that the measurement is not affected by the heat dissipated by the MCU and it’s surrounding circuitry.
For more detail: A Digital Thermometer Hygrometer With Analog Displays
- Why did the author choose servo motors instead of analog meters?
The author chose two servos to make the project more fun while avoiding the use of traditional analog meters. - What type of display is used for the output?
The project uses two needles driven by servos to display readings in a retro style rather than an LCD or 7 segment display. - Which sensor is used to measure temperature and humidity?
The SHT21 sensor from Sensirion is used for the measurements. - How is the sensor connected to the microcontroller?
The sensor mounted on a breakout board is connected to the ATMega328p board via a ribbon cable. - Why is the sensor placed at a distance from the MCU?
The sensor is placed at some distance so that the measurement is not affected by the heat dissipated by the MCU and its surrounding circuitry. - Is this project considered easy to build?
Yes, the article states that building a digital thermometer/hygrometer is pretty easy and quite useful.
