lcd module 1602 python code supplier

The LCD power supply voltage can be varied to adjust the contrast. A potentiometer can be used to allow adjusting this, but here we will just make a simple voltage divider out of two resistors.

It is unusual to need to read data from the LCD. Mostly you"ll just want to write data (text to display, cursor position etc.) to it, so we"ll just wire the read/write select pin RW to ground, indicating that it will always be in write mode.

The LCD provides both 8-bit and 4-bit modes. We will use the 4-bit mode, so only pins DB4, DB5, DB6, DB7 are actually used for communication. Pins DB0, DB1, DB2 and DB3 are left disconnected.

Raspberry Pi 16×2 LCD I2C Interfacing and Python Programming– I have been using 16×2 LCD for quite a long time in different Arduino and IoT related projects. You know we have two types of the 16×2 LCD, the normal one used more wires and the other one is based on the I2C interface which needs only two wires.

The backpack module uses the I-squred-C (or I2C) protocol to communicate with the Raspberry Pi, which uses only two wires: SDA and SCL (data and clock). Please note that the display is a 5 volt device, and it is powered by 5 volts, but due to design of the I2C protocol, and the fact that the Raspberry Pi is the controlling device, it is safe to connect such display to the Raspberry Pi directly.

I suggest using wires of different colors to connect the LCD display. This minimizes the risk of damage due to incorrect connections. For example, I’m using

Before you start using the I2C 16×2 LCD display with Python, you need to make sure that the I2C protocol is enabled on your Raspberry Pi. You can use the sudo raspi-config utility to take care of that. This program is navigated using keyboard arrows, tab and the Enter key. Look for I2C in the interfacing options and enable it. Enabling I2C requires a reboot.

The 27 hexadecimal addresses happen to be the most common, but your display’s address may be different. For example, it could be 3f. This will depend on the chip version of the backpack module. As long as the i2cdetect command shows the display is connected, you are good to go.

The easiest way to program this 16×2 I2C LCD display in Python is by using a dedicated library. There are many to choose from. I like things simple, so the library I recommend is rpi_lcd.

This library has the default 27 address hard-coded. If your display has a different address you will need to change it. You need to find the library on your system and the following command should do that for you.

I"m trying to use some Python code to write text on a 16x2 LCD display ("compatible" with classics Hitachi HD44780) connected to a RaspberryPi model B+ via an I2C "back-pack".

The problem is that running multiple times this sample code, in sequence, one time it goes OK and the next time the LCD displays random characters; then again, one OK, one wrong.

In the previous project of the Raspberry Pi Series, I have shown you how to blink an LED using Raspberry Pi and Python Program. Moving forward in the series, in this project, I’ll show you the interfacing 16×2 LCD with Raspberry Pi.

In this project, you can see all the steps for Interfacing a 16×2 LCD with Raspberry Pi like circuit diagram, components, working, Python Program and explanation of the code.

Even though the Raspberry Pi computer is capable of doing many tasks, it doesn’t have a display for implementing it in simple projects. A 16×2 Alphanumeric Character LCD Display is a very important types of display for displaying some basic and vital information.

A 16×2 LCD is one of the most popular display modules among hobbyists, students and even electronics professionals. It supports 16 characters per row and has two such rows. Almost all the 16×2 LCD Display Modules that are available in the market are based on the Hitachi’s HD44780 LCD Controller.

The pin description in the above table shows that a 16×2 LCD has 8 data pins. Using these data pins, we can configure the 16×2 LCD in either 8 – bit mode or 4 – bit mode. I’ll show the circuit diagram for both the modes.

In 8 – bit mode, all the 8 data pins i.e. D0 to D7 are used for transferring data. This type of connection requires more pins on the Raspberry Pi. Hence, we have opted for 4 – bit mode of LCD. The circuit diagram (with Fritzing parts) is shown below.

The following image shows the wiring diagram of the featured circuit of this project i.e. LCD in 4 – bit mode. In this mode, only 4 data pins i.e. D4 to D7 of the LCD are used.

NOTE: In this project, we have used the 4 – bit mode of the 16×2 LCD display. The Python code explained here is also related to this configuration. Slight modifications are needed in the Python Program if the circuit is configured in 8 – bit mode.

The design of the circuit for Interfacing 16×2 LCD with Raspberry Pi is very simple. First, connect pins 1 and 16 of the LCD to GND and pins 2 and 15 to 5V supply.

Then connect a 10KΩ Potentiometer to pin 3 of the LCD, which is the contrast adjust pin. The three control pins of the LCD i.e. RS (Pin 4), RW (Pin 5) and E (Pin 6) are connected to GPIO Pin 7 (Physical Pin 26), GND and GPIO Pin 8 (Physical Pin 24).

Now, the data pins of the LCD. Since we are configuring the LCD in 4 – bit mode, we need only 4 data pins (D4 to D7). D4 of LCD is connected to GPIO25 (Physical Pin 22), D5 to GPIO24 (Physical Pin 18), D6 to GPIO24 (Physical Pin 16) and D7 to GPIO18 (Physical Pin 12).

The working of project for Interfacing 16×2 LCD with Raspberry Pi is very simple. After making the connections as per the circuit diagram, login to your Raspberry Pi using SSH Client like Putty in Windows.

I’ve created a folder named “Python_Progs” on the desktop of the Raspberry Pi. So, I’ll be saving my Python Program for Interfacing 16 x 2 LCD with Raspberry Pi in this folder.

Using “cd” commands in the terminal, change to this directory. After that, open an empty Python file with name “lcdPi.py” using the following command in the terminal.

Now, copy the above code and paste it in the editor. It is important to properly use the Tab characters as they help in grouping the instructions in Python.

Save the file and close the editor. To test the code, type the following command in the terminal. If everything is fine with your connections and Python Program, you should be able to see the text on the 16×2 LCD.

First, I’ve imported the RPi.GPIO Python Package as GPIO (here after called as GPIO Package) and sleep from time package. Then, I have assigned the pin for LCD i.e. RS, E, D4, D5, D6 and D7. The numbering scheme I followed is GPIO or BCM Scheme.

Finally, using some own functions like lcd_init, lcd_string, lcd_display, etc. I’ve transmitted the data to be printed from the Raspberry Pi to the 16×2 LCD Module.

By interfacing 16×2 LCD with Raspberry Pi, we can have a simple display option for our raspberry Pi which can display some basic information like Date, Time, Status of a GPIO Pin, etc.

Many simple and complex application of Raspberry Pi like weather station, temperature control, robotic vehicles, etc. needs this small 16×2 LCD Display.

Connecting an LCD to your Raspberry Pi will spice up almost any project, but what if your pins are tied up with connections to other modules? No problem, just connect your LCD with I2C, it only uses two pins (well, four if you count the ground and power).

In this tutorial, I’ll show you everything you need to set up an LCD using I2C, but if you want to learn more about I2C and the details of how it works, check out our article Basics of the I2C Communication Protocol.

BONUS: I made a quick start guide for this tutorial that you can download and go back to later if you can’t set this up right now. It covers all of the steps, diagrams, and code you need to get started.

There are a couple ways to use I2C to connect an LCD to the Raspberry Pi. The simplest is to get an LCD with an I2C backpack. But the hardcore DIY way is to use a standard HD44780 LCD and connect it to the Pi via a chip called the PCF8574.

The PCF8574 converts the I2C signal sent from the Pi into a parallel signal that can be used by the LCD. Most I2C LCDs use the PCF8574 anyway. I’ll explain how to connect it both ways in a minute.

I’ll also show you how to program the LCD using Python, and provide examples for how to print and position the text, clear the screen, scroll text, print data from a sensor, print the date and time, and print the IP address of your Pi.

Connecting an LCD with an I2C backpack is pretty self-explanatory. Connect the SDA pin on the Pi to the SDA pin on the LCD, and the SCL pin on the Pi to the SCL pin on the LCD. The ground and Vcc pins will also need to be connected. Most LCDs can operate with 3.3V, but they’re meant to be run on 5V, so connect it to the 5V pin of the Pi if possible.

If you have an LCD without I2C and have a PCF8574 chip lying around, you can use it to connect your LCD with a little extra wiring. The PCF8574 is an 8 bit I/O expander which converts a parallel signal into I2C and vice-versa. The Raspberry Pi sends data to the PCF8574 via I2C. The PCF8574 then converts the I2C signal into a 4 bit parallel signal, which is relayed to the LCD.

Before we get into the programming, we need to make sure the I2C module is enabled on the Pi and install a couple tools that will make it easier to use I2C.

Now we need to install a program called I2C-tools, which will tell us the I2C address of the LCD when it’s connected to the Pi. So at the command prompt, enter sudo apt-get install i2c-tools.

Next we need to install SMBUS, which gives the Python library we’re going to use access to the I2C bus on the Pi. At the command prompt, enter sudo apt-get install python-smbus.

Now reboot the Pi and log in again. With your LCD connected, enter i2cdetect -y 1 at the command prompt. This will show you a table of addresses for each I2C device connected to your Pi:

We’ll be using Python to program the LCD, so if this is your first time writing/running a Python program, you may want to check out How to Write and Run a Python Program on the Raspberry Pi before proceeding.

I found a Python I2C library that has a good set of functions and works pretty well. This library was originally posted here, then expanded and improved by GitHub user DenisFromHR.

There are a couple things you may need to change in the code above, depending on your set up. On line 19 there is a function that defines the port for the I2C bus (I2CBUS = 0). Older Raspberry Pi’s used port 0, but newer models use port 1. So depending on which RPi model you have, you might need to change this from 0 to 1.

The function mylcd.lcd_display_string() prints text to the screen and also lets you chose where to position it. The function is used as mylcd.lcd_display_string("TEXT TO PRINT", ROW, COLUMN). For example, the following code prints “Hello World!” to row 2, column 3:

On a 16×2 LCD, the rows are numbered 1 – 2, while the columns are numbered 0 – 15. So to print “Hello World!” at the first column of the top row, you would use mylcd.lcd_display_string("Hello World!", 1, 0).

You can create any pattern you want and print it to the display as a custom character. Each character is an array of 5 x 8 pixels. Up to 8 custom characters can be defined and stored in the LCD’s memory. This custom character generator will help you create the bit array needed to define the characters in the LCD memory.

The code below will display data from a DHT11 temperature and humidity sensor. Follow this tutorial for instructions on how to set up the DHT11 on the Raspberry Pi. The DHT11 signal pin is connected to BCM pin 4 (physical pin 7 of the RPi).

By inserting the variable from your sensor into the mylcd.lcd_display_string() function (line 22 in the code above) you can print the sensor data just like any other text string.

These programs are just basic examples of ways you can control text on your LCD. Try changing things around and combining the code to get some interesting effects. For example, you can make some fun animations by scrolling with custom characters. Don’t have enough screen space to output all of your sensor data? Just print and clear each reading for a couple seconds in a loop.

After doing so many IoT projects with my ODROID-C2 like the seismograph detector (http://bit.ly/2uWqas0), the wine cellar preserver, and notifier (http://bit.ly/2wch3Vb), the Gmail mechanical notifier (http://bit.ly/2wch3Vb) and many others, I was thinking about adding a low energy, low cost LCD screen for depicting any valuable information of all those electronic constructions for the sake of portability and readability. The I2C TWI 1602 16x2 Serial LCD Module Display for Arduino JD is the ideal solution for materializing all those specifications and much more.

This LCD Module Display communicates with an ODROID-C2 using the I2C protocol with just 4 wires. The I2C protocol is a multi-master, multi-slave, packet switched, single-ended, serial computer bus invented by Philips Semiconductor (now NXP Semiconductors). It is typically used for attaching lower-speed peripheral ICs to processors and microcontrollers in short-distance, intra-board communication (http://bit.ly/2qGiYP4). In the following lines, we describe how this connection can be materialized physically and programmatically. The language used is Python 2.7, and the program can be implemented easily into other projects as a module with minor modifications.

For the wiring, please follow the schematic in Figure 1. There are 2 important wires for the communication: the SDA that provides the I2C serial data, and the SCL that provides the I2C serial clock. The SDA is on Pin 3 on the I2C LCD Display and is connected on GPIO Pin 3 of ODROID-C2. The SCL is on Pin 4 and is connected on GPIO Pin 5 of the ODROID-C2. For visual reference see the schematic in Figure 1 and Hardkernel’s excellent 40-pin layout for ODROID-C2 (http://bit.ly/2aXAlmt). These will help to make sure the wiring is correct. Now that we have our hardware ready, let’s see how we can establish a communication between the ODROID-C2 and the I2C Serial LCD Display using the I2C protocol. The GPIO Pin 2 provides the VCC power, +5V, for the LCD Display and GPIO Pin 39 is of course the ground, GND.

We will establish a connection between ODROID-C2 and the Serial LCD Display using the I2C protocol. The steps we will follow here are almost identical with those presented on our previous article under the title "Seismograph Earthquake Detector: Measuring Seismic Acceleration using the ODROID-C2", published in ODROID magazine"s July issue (http://bit.ly/2uWqas0). In that article, we described all the necessary steps necessary to establish communication between the ODROID-C2 and the MMA7455 accelerometer, which also uses I2C. We will repeat the same procedure here for the sake of the consistency and the integrity of this article.

You will need to install SMBus and I2C-Tools, since the LCD Module Display uses this protocol to communicate with the ODROID-C2. The System Management Bus, or SMBus, is a simple, single-ended, two-wire bus for lightweight communication. It is most commonly found in computer motherboards for communicating with the power source (http://bit.ly/2rAWhuU).

If ‘27’ is shown on line 20 under column 7, this means the LCD Display is communicating with the ODROID-C2 and working properly. More details may be found at http://bit.ly/2qCQM1s.

We will present the code in chunks, as we do always, in order to be better understood by our readers. The code is slightly modified from this the source here (http://bit.ly/2w2a957) and adopted for the needs of this project. The code is in Python and what it mainly does is to establish a connection between the ODROID-C2 and LCD Display by opening a I2C connection allowing 16 characters on two lines to be displayed. You can download the code here (http://bit.ly/2vzSMqd) and run it for immediate results, or if you don’t want to retype all the code. First, import the necessary modules:

The above code can be written in any text editor. However, it"s easier to do with a Python IDE, such as Python IDLE. The Python IDLE is accessible from the Mate desktop (Application -> Programming -> IDLE). As soon as we write the program, we can save it under any name, and finally run it as shown in Figure 3:

The "Drive I2C LCD screen with ODROID-C2" application can be implemented in any other project with minor modifications as a Python module. The only piece of code that has to be altered in order to change the lines of characters depicted on the LCD display are the following:

The principle of the LCD1602 liquid crystal display is to use the physical characteristics of the liquid crystal to control the display area by voltage,

Before we get into the programming, we need to make sure the I2C module is enabled on the Pi and install a couple tools that will make it easier to use I2C.

By inserting the variable from your sensor into the mylcd.lcd_display_string() function (line 22 in the code above) you can print the sensor data just like any other text string.

In this tutorial, we will learn Interfacing of 16×2 LCD Display with Raspberry Pi Pico. An LCD is an electronic display module that uses liquid crystal technology to produce a visible image. The 16×2 LCD display is a very basic module commonly used in electronic circuit applications. The 16×2 translates 16 characters per line in 2 such lines. In this LCD each character is displayed in a 5×8 pixel matrix.

Raspberry Pi Pico which was released a few months ago requires some LCD Display in engineering applications. Here we will go through the LCD Display details and features. The LCD Display is based on HD44780 Driver. There are I2C versions and non-I2C versions of LCD Display. We will take both of these LCDs as an example and interface with Raspberry Pi Pico. We will write MicroPython Code for Interfacing 16×2 LCD Display with Raspberry Pi Pico.

16×2 LCD is named so because it has 16 Columns and 2 Rows. So, it will have (16×2=32) 32 characters in total and each character will be made of 5×8 Pixel Dots. A Single character with all its Pixels is shown in the below picture.

Each character has (5×8=40) 40 Pixels and for 32 Characters we will have (32×40) 1280 Pixels. Further, the LCD should also be instructed about the Position of the Pixels. Hence it will be a complicated task to handle everything with the help of a microcontroller. Hence the LCD uses an interface IC like HD44780. This IC is mounted on the backside of the LCD Module. You can check the HD44780 Datasheet for more information.

The function of this IC is to get the Commands and Data from the MCU and process them to display meaningful information on LCD Screen. The LCD operating Voltage is 4.7V to 5.3V & the Current consumption is 1mA without a backlight. It can work on both 8-bit and 4-bit mode

There are two section pins on the whole 16×2 LCD module. Some of them are data pins and some are command pins. Somehow, every pin has a role in controlling a single pixel on the display.

This display incorporates an I2C interface that requires only 2 pins on a microcontroller to the interface. The I2C interface is a daughter board attached to the back of the LCD module. The I2C address for these displays is either 0x3F or 0x27.

The adapter has an 8-Bit I/O Expander chip PCF8574. This chip converts the I2C data from a microcontroller into the parallel data required by the LCD display. There is a small trimpot to make fine adjustments to the contrast of the display. In addition, there is a jumper on the board that supplies power to the backlight.

Now, let us interface the 16×2 LCD Display with Raspberry Pi Pico. You can use Fritzing Software to draw the Schematic. You can assemble the circuit on breadboard as shown in the image below.

Connect the pin 1, 5 & 16 of LCD to GND of Raspberry Pi Pico. Similarly, connect the Pin 2 & 15 of LCD to 5V Pin, i.e Vbus of Raspberry Pi Pico. Connect the Pin 4, 6, 11, 12, 13, 14 of LCD Display to Raspberry Pi Pico GP16, GP17, GP18, GP19, GP20, GP21 Pin.

Raspberry Pi Pico supports MicroPython Program for interfacing 16×2 LCD Display. You can either use Thonny IDE or uPyCraft IDE for running the MicroPython Code.

The above code is valid for 16×2 LCD Display without any I2C Module. The PCF8574 I2C or SMBus module simplifies the above connection. Instead of using so many wiring, you can use this IC Module and convert the data output lines just to 2 pins.

Hence the LCD Display becomes an I2C Display with an I2C address of 0x27. The connection between the Raspberry Pi Pico and I2C LCD is very simples as shown below in the schematic.

Connect the LCD VCC & GND Pin to Raspberry Pi Pico 5V & GND Pin respectively. Connect the SDA & SCL pin of LCD to Raspberry Pi Pico GP8 & GP9 respectively.