This is a quick tutorial for our 84x48 pixel monochrome LCD display. These displays are small, only about 1.5" diameter, but very readable due and comes with a backlight. This display is made of 84x48 individual pixels, so you can use it for graphics, text or bitmaps. These displays are inexpensive, easy to use, require only a few digital I/O pins and are fairly low power as well.
To drive the display, you will need 3 to 5 digital output pins (depending on whether you want to manually control the chip select and reset lines). Another pin can be used to control (via on/off or PWM) the backlight. To make things easy for you, we've written a nice graphics library that can print text, pixels, rectangles, circles and lines!
The library is written for the Arduino but can easily be ported to your favorite microcontroller.
You can pick up one of these displays at the adafruit shop!
The display uses the PCD8544 controller chip from Philips and were used in Nokia 3310 and 5110 cell phones. This chip is designed to run only at 3.3V and have 3v communication levels, so for 5V microcontrollers a logic level shifter is required (otherwise you could easily damage the display).
If you want to use the backlight, that can draw up to 80mA (4 white LEDs at 20mA each). The backlight pin is connected to a transistor so you can PWM all 4 LEDs at once from a microcontroller pin.
The LCD runs at 3.3V so you'll need to use a level shifting chip to use with a 5V microcontroller. The following will assume that is the case. If you're running a 3.3V microcontroller system, you can skip the level shifter.
We'll assume you want to use this in a breadboard, take a piece of 0.1" header 8 pins long and insert it into a breadboard.
Slide either side of the LCD onto the header, the 'thicker' end is the top.
Solder all the pins.
Place the level shifter chip off to the side. Pin 1 is on the left here.
We'll start with the power lines. the system must be powered by 3.3V so red here is connected to the 3V pin from the Arduino. Ground is black.
- Connect pin 1 of the 4050, the LCD VCC pin and the LCD backlight pin to 3.3V.
- Connect pin 8 of the 4050 and the GND pin of the LCD to ground.
Verify you see the backlight LEDs light up
Dimmable Backlight Option:
Newer versions of these boards have a sightly different backlight circuit that is brighter than the older boards. You can add a pot to the backlight so that you can control the brightness. (This works with the older boards too, but the range of brightness will be lower).
The optional pot can be wired as in the photo below:
Next we'll start wiring up the data lines.
- Connect the RST (reset) pin of the LCD (orange wire) to pin 2 of the 4050
- Connect the CS (chip select) pin (yellow wire) to pin 4 of the 4050.
- Connect the D/C (data/command) pin (green wire) to pin 6 of the 4050.
- DIN (data in) pin (blue wire) to pin 15 of the 4050
- CLK(clock) pin (purple wire) to pin 12 of the 4050.
Then we can connect the data lines from the arduino to the LCD. We can use any
5 pins but you may want to start with our example first.
- Arduino pin 3 (orange) goes to pin 3 of the 4050.
- Arduino pin 4 (yellow) goes to pin 5 of the 4050.
- Arduino pin 5 (green) goes to pin 7 of the 4050.
- Arduino pin 6 (blue) goes to pin 14 of the 4050.
- Arduino pin 7 (violet) goes to pin 11 of the 4050.
Now you are ready to test!
You can find our Nokia Display Arduino library on github
. To install it, click this button to download the compressed ZIP file then install it. This guide
will help you with the install process if you have never installed an Arduino library.
Then you'll have to do the same for the Adafruit GFX Graphics core library, available from github
. Click the button to download it. Then install Adafruit_GFX just like the library you've done except this time name it Adafruit_GFX
Restart the Arduino software. You should see a new example folder called Adafruit_PCD8544 and inside, an example called pcdtest. Open up that sketch and upload it to your Arduino. You should see the example test sequence.
You can control the backlight, its much brighter when you connect the backlight pin to 5V (you don't need a level shifter if you are using a Nokia display from Adafruit). You can control the backlight using an Arduino pin since there is a transistor on the board.
We have a ready to go basic graphics library that has primitives for bitmaps, shapes and text. You can probably do everything you want using it. Because of the way the display works we need to buffer the entire display in ram which is 84x48 bits (504 bytes). However, screen updates are very fast.
For more details about the Adafruit GFX library, please visit http://learn.adafruit.com/adafruit-gfx-graphics-library - it supports lines, rectangles, roundrects, circles, text of different sizes etc.
Note that since this display is MONOCHROMATIC it only supports two colors: BLACK
. BLACK is a displayed dot and WHITE is for erasing pixels
Dont forget, after drawing anything to the screen, call display() to write it out to the LCD!
You can save some pins by connecting the CS pin to ground (this means you cant reuse the LCD's pins between screen updates but maybe thats OK. You can also connect the RST pin to the Arduino reset so that it will reset the screen automatically.