Working With Raspberry Pi And 16 X 2 LCD Display

Anish Ansari
May 19, 2017
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In this tutorial, we will be talking about how to interface the Raspberry Pi and 16 X 2 LCD using GPIO and Python.

At the end of this blog, you will be able to,

print your custom message on 16 X 2 LCD
print the current time, weather, and weather condition in LCD

To follow this tutorial, you will need the following.

Raspberry Pi (We are using Raspberry Pi B+ model)
16 X 2 LCD Display
Resistors
Jumper Wires (Male to male and Female to male)
Breadboard

LCD Pinout

GROUND (GND)
VCC +5V (not to be confused with 3.3V)
Contrast Adjustment (Vo, usually we use variable resistor)
Register Select (RS)RS=0: Command, RS=1: Data
Read/Write(RW)RW = 0: WriteRW=1: Read
Enable
Bit (0) Not required in 4bit operation
Bit (1) Not required in 4bit operation
Bit (2) Not required in 4bit operation
Bit (3) Not required in 4bit operation
Bit 4
Bit 5
Bit 6
Bit 7
LED Backlight Anode (+)
LED Backlight Cathode (-)

Here is how we wired up our LCD

Note

In order to control the contrast, you can adjust the voltage presented to Pin 3. This must be between 0 and 5V. We used a resistor between pin 3 of LCD to GND of Pi.

Your circuit should look something like this.

Raspberry Pi b+ GPIO Pinout for reference.

Python Code

Code Goes Here

Displaying current date, time and weather info

In the above tutorial, we saw how to display the custom message on 16 X 2 LCD using raspberry pi and python.Now we shall move on how to display the current weather info on LCD:

First, we will need to download the python weather API.Download the pywapi library using the following command on your piwget https://launchpad.net/python-weather-api/trunk/0.3.8/+download/pywapi-0.3.8.tar.gz

This will download the tar file of the pywapi library

Extract the tar file using
tar -zxvf pywapi-0.3.8.tar.gz

Now, enter the directory using

cd pywapi-0.3.8

Now, run the following command

python setup.py build
python setup.py install

You are done with installing the pywapi library. Now, download the source code into your Pi, and save it with .py extension (ex - lcd.py).

To run the code, use the following command.

python lcd.py

Now, you should be able to see the output as below.

The next step is to find the location code/id of your desired city.

https://weather.codes/

Open the link and enter your city. You should be able to get unique weather id of your city.

For example, for Bangalore, the weather id is INXX0012, similarly for Kathmandu is NPXX0002.

Now, open your source code and edit the line 8 with your city’s unique weather id.

#define the weather location id
weather_com_result = pywapi.get_weather_from_weather_com('NPXX0003')

Now, you should be able to see the weather info of Kathmandu as below.