Second Multi-functional Weather Station (3.5 Inch LCD)
Introduction: Second Multi-functional Weather Station (3.5 Inch LCD)
As I mentioned in the previous Instructable, this device is the most frequently utilized DIY output among the many other Arduino project outcomes.
But the first version has several problems I'll describe details in the next step.
Therefore, I made this second version of the Multi-functional Weather Station having a bigger screen, simplified circuit, and more readable sketch program code.
The overall functionality of the second version is almost the same as the first one.
But information displaying method is changed to suit my daily usage pattern and unnecessary sensors are removed for simplifying the overall circuitry.
Let's look at more details of this second version.
Step 1: Some Improvements From the First Version
The picture above shows the first version of the device in action at night hours.
Although it was a little bit useful for showing needed information all time, it has the following problems.
- Unnecessary sensors (noise, LDR) and redundant SD card breakout boards are emitting too many lights which can distress sound sleep
- 1.8 inch LCD screen is so small for immediately recognizing information displayed
- Displayed photo image quality is poor to be utilized as a digital album because of the small LCD size
-Looking at multiple screens is necessary for checking time and other relevant weather information
For improvement, the bigger 3.5 inch LCD is used for displaying high-resolution images and bigger time and weather information messages on the screen.
The black acrylic board of the front cover is added to block unnecessary lights from the internal system boards.
Then let's look more other details of the new device.
Step 2: Schematics and Parts
When comparing the schematics with the first version, overall circuitry becomes more simplified.
Somewhat less useful sensors (LM393 base sound sensor and LDR) are removed from the second circuit version.
As the integrated SD card circuit to the 3.5 inch LCD module is used, overall circuitry becomes more compact.
The following parts are utilized.
- Arduino Mega2560 board
- 3.5 inch LCD module (SD reader is integrated)
- DS3231 real-time clock
- DHT 22 temperature and humidity sensor
- BMP280 atmospheric pressure sensor (including temperature sensor)
- Acrylic boards (Transparent and black acrylic boards)
- 12V external power supply
The most important part is the 3.5 inch LCD module in this project.
I bought three of these at Aliexpress at less than 10 dollars each.
It can support 480x320 resolution with ILI9486 video driver IC.
The LCD manufacture is providing their device driver and graphic library as well as several sample demo programs.
But I want to use Adafruit graphic library as it was frequently used in many previous projects and is familiar.
But I can't find any helpful technical resources to interface this LCD module with Adafruit graphic library.
Therefore, I slightly modified the demo program provided by the manufacture for making the digital album that displays photo images on LCD.
Step 3: Wiring and Mounting Parts
Wiring and configuration details of sensors and other break-out boards are explained in the previous Instructable listed below.
https://www.instructables.com/Multi-functional-Weather-Station-Mega2560-Version/
As the first Multi-functional Weather Station circuit is utilizing similar electronic components, the overall wiring and configuration scheme is the same for the second version.
Installing DHT22, BMP 280, and DS3231 are already explained several times in the previous Instructables.
Therefore, I'll explain only the wiring and configuration method of 3.5 inch LCD module as this component is a new one included in the second version of the circuit.
The LCD module is called as 3.5 inch 8 bit TFT LCD module for Arduino Uno at Aliexpress.
Likewise, the LCD module can be plugged into the Uno board similar to other HAT boards.
As the wiring scheme is widely different among LCD manufacturers, the following method will be only relevant for the LCD module I bought.
The LCD module requires 8 data lines, 5 LCD control lines, and 4 SD card interfacing lines with Arduino as follows. 152