pico lcd display factory

In this tutorial Tony Goodhew explains how to use the basic graphics procedures which are included in the display driver, and for the ambitious makers out there he also provides examples for advanced shapes and graphics!

All the other graphical and text objects we would like to display can be built from this single pixel instruction; such as lines, circles, rectangles, triangles and text strings at different sizes.

This is all carried out with code. Display manufacturers usually supply some of these procedures/methods but leave the rest up to the end user to construct.

The third line here imports the Framebuffer library which includes several very useful routines to draw objects on the display. The garbage collection library, gc, has also been imported so that we can check how much memory is available.

The following methods draw shapes (such as those above) onto the FrameBuffer. They only become visible to the user once the lcd.show() instruction is executed.

Each program contains the screen driver code, sets up the buttons/joystick (if applicable), sets the width and height variables, loads the essential libraries, defines the colour (R, G, B) and clear (c) procedures, then displays some colour checking text like this:

Using lcd.fill_rect, fill the whole screen green and then fill the middle of the screen black, leaving a 10 pixel border. Put red 10-pixel squares in each corner.

Draw a dark grey rectangle in the centre of the screen. Draw 500 white pixels inside the square, none touching the edge. (Random was explained in the previous display tutorial.)

This is routine is very complicated. It splits the original triangle into two with a horizontal line and then fills them in. If you uncomment all the # lcd.show() lines and sleep instructions it will slow right down and you can see it working (unfortunately, the 2” display needs such a large buffer that there is not enough memory for the filled triangles code):

For the imports we added the math library as this is needed for Sin and Cos in graph plotting. The random library has also been imported, for the randomly generated triangles. These are followed by the basic LCD board setup we covered earlier.

In the centre of the screen display a ‘bull’s eye’ circular target with a ‘gold’ centre, 4 other colours and scores 10, 8, 6, 4 and 2 written in the appropriate positions.

You may have noticed that on some screens the text is very small and difficult to read. In a following tutorial will add an extra font, with more characters, which we can display in different sizes.

In this tutorial, we will learn how to interface I2C LCD with Raspberry Pi Pico and how to display simple text/numbers and custom characters on I2C LCD. This I2C LCD is a 16×2 device which means it can display 16 columns by two rows of characters. The characters are alphanumeric, but you can create custom characters for basic graphics, bar graphs that kind of thing. The LCD has the usual type of hd44780 controller, and it also has an I2C circuit connected with it which makes it easy to connect to the Pi Pico board. 16X2 LCD without I2C circuit has sixteen pins.

But if we want to connect this board directly with Raspberry Pi Pico, we have to use at least eight pins of our board which will be a waste. So the better solution is to use an I2C LCD instead of typical 16×2 LCD. In this tutorial, we are using 16×2 I2C LCD, but LCD of any size will also work the same way as we will learn in this tutorial. The advantage of using an I2C LCD is that we only need to use four pins (including the power pins) of Raspberry Pi Pico to connect with this display.

At the backside of this liquid crystal display, you can also see a variable resistor. This variable resistor is used to modify the brightness of the LCD. This potentiometer is very handy when you are using this display module in different light conditions.

Before we start this lesson, make sure you are familiar with and have the latest version of Python3 installed in your system and set up MicroPython in your Raspberry Pi Pico. Additionally, you should have a running Integrated Development Environment(IDE) to do the programming. We will be using the same Thonny IDE as we have done previously when we learned how to blink and chase LEDs in MicroPython here:

In this section, we will show you how to connect I2C LCD with Raspberry Pi Pico. The I2C LCD will be connected with the Pi Pico with its 4 pins (GND, VCC, SDA and SCL).

Raspberry Pi Pico has two I2Ccontrollers. Both I2C controllers are accessible through GPIO pins of Raspberry Pi Pico. The following table shows the connection of GPIO pins with both I2C controllers. Each connection of the controller can be configured through multiple GPIO pins as shown in the figure. But before using an I2C controller, you should configure in software which GPIO pins you want to use with a specific I2C controller.

The VCC pin is connected with the VBUS pin from the Raspberry Pi Pico to power up. Both the grounds of the two devices are connected in common. The SCL pin of I2C LCD is connected with I2C0 SCL pin of Pi Pico. Likewise, the SDA pin is connected with the I2C0 SDA pin of Pi Pico.

When you connect your I2C display with Raspberry Pi Pico, you need to check its address. Because every I2C device has an address associated with it. For many devices of I2C LCD, the default address is 0x27 where 0x shows hex format of the numbers. But address can be different in some cases. This address depends on the position of pads A0, A1, and A2 on the I2C controller on this device.

For this project we will require two libraries: lcd_api.py and i2c_lcd.py. Copy both of these libraries and save them in your Raspberry Pi Pico with the respective file names. Open a new file in Thonny. Copy the libraries from the links given above. Save them to Raspberry Pi Pico with names lcd_api.pyand i2c_lcd.py under the lib folder.

This code will display the message “Lets Count 0-10!” for two seconds. After that, it will clear the LCD and display numbers from 0 to 10 after a delay of 1 second.

Firstly, we will be importing the I2C class from the machine module. We also import the sleep module so that we will be able to add a delay in between our messages. Also, import LcdApi from the lcd_api library that we just uploaded to our board and I2clcd from the i2c_lcd library.

Additionally, totalRows and totalColumns specify the number of rows and columns of the display which in our case is 16×2. If you want to use a screen of any other size, you need to need to change the number here accordingly, for example, the 20×4 display.

This line is used to initialize the I2C connection for the library by creating an object ‘lcd’. The first argument to the function I2cLcd() is the i2c object declared previously, the second argument is the address of our I2C LCD. Third and fourth arguments are the size in terms of the number of columns and number of rows.

Next, we run an infinite loop inside which we first display the message “Lets Count 0-10!” for 2 seconds. Then we clear the screen using the clear() method on the lcd object. After that we use a for loop to display numbers from 0 to 10 after a delay of 1 second each. After each number is displayed, wait for one second, then clear() will erase the text.

To test this program with Raspberry Pi Pico, upload this main.py file to your board. Once the code is uploaded to the board, adjust the brightness of the display through the potentiometer until the LCD starts displaying the messages:

For our 16×2 LCD display that we are using, we have the option to display custom characters as well. In this particular LCD, each block consists of 5×8 pixels. These can be used to display custom characters by setting the state of each pixel inside a byte array.

There is a very simple way to generate the byte array of your own custom character. Head over to the following custom character generator: (LCD Custom Character Generator).

In our case, we will display a heart character on the screen. We will require the hex data that is highlighted in the red rectangle below to form our byte array. We will use these values inside our byte array while programming the Raspberry Pi Pico to display custom characters.

Next, we will create the custom character by calling lcd.custom_char() and pass a number between 0-7 (allocated location) and the variable containing the bytearray as parameters inside it.

To test this program with Raspberry Pi Pico, upload this main.py file to your board. Once the code is uploaded to the board, adjust the brightness of the display through the potentiometer until the LCD starts displaying the message.

Please take care of the direction when you connect Pico, an USB port is printed to indicate . You can also check the pin of Pico and the LCD board when connecting.

Open main.c under the c folder, you can change the routine you need. This routine can drive the display of our company"s Pico series and the source code will be updated all the time. Please select the corresponding LCD or OLED test function and comment out the irrelevant functions.

After the compilation is complete, the uf2 file will be generated. Press and hold the button on the Pico board, connect the pico to the USB port of the Raspberry Pi through the Micro USB cable, and release the button. After connecting, the Raspberry Pi will automatically recognize a removable disk (RPI-RP2), and copy the main.uf2 file in the build folder to the recognized removable disk (RPI-RP2).

1. Press and hold the BOOTSET button on the Pico board, connect the pico to the USB port of the computer through the Micro USB cable, and release the button after the computer recognizes a removable hard disk (RPI-RP2).

From what I can tell, to display a special character you will have to send a hexadecimal string which is converted by the display driver according to its charset.

The whole documentation for your display driver is available here. But, if you just want to look into the charset, you can find it on wikipedia as well.

In the charset, the character you"re looking for is located in the bottom right corner. It"s binary identifier – which you can identify by looking at the table head and the beginning of its corresponding row – is in this case 11011111. However, the SERLCD want"s you to send hexadecimal to it.

1.14" LCD Display Module For Pico-Embedded ST7789 Driver, Using SPI Bus Features At A Glance 240×135 resolution, IPS screen, 65K RGB colors, clear and colorful displaying effect

Specifications Raspberry Pi Pico Header Compatibility Onboard Female Pin Header For Direct Attaching To Raspberry Pi Pico 4x User Buttons For Easy Interacting