In the previous tutorial I showed how to build a weather station using DHT11 and BMP180 with an Arduino. However, the project has a downside which is the power consumption of the 16X2 LCD. If we were building a battery powered project with the desire to last for several weeks and probably several months, like a weather station for instance, then we’ll have to replace the LCD keypad shield from the previous tutorials and go for something like the low powered Nokia 5110 84×84 LCD display. In this tutorial I will be showing you how to drive this display with the Arduino and thus build projects with longer battery life.
Since we are just going to drive the display we won’t be needing sensors for this tutorial, however we will need the components listed below which include the Nokia 5110 itself and we will show how to drive the display using an Arduino board.
The Nokia 5110 display is basically a graphic LCD display useful for a lot of applications. It was intended originally to be used as a screen for cell phones and was used in lots of mobile phones during the 90’s. This display uses a low powered CMOS LCD controller/driver PCD8544, which drives the graphic display of size 84×48. It is very cheap and costs about 3$. You can get one here.
The Nokia 5110 LCD can display text, graphics as well as bitmaps. When this display is fully lit, it draws about 10mA but with the backlight off, it draws as low as 0.4mA. The power consumed by this display is very low compared to that of the keypad LCD shield used in the previous tutorial. I will be using the Arduino Mega for this tutorial as usual and you can buy one here. You can also buy jumpers, breadboards and power bank which you will be needing for this tutorial.
With the components acquired (links attached to the list), lets wire them up.
The display has two sides to which headers pins can be connected. You can pick one of the sides and solder header pins so that the display can fit firmly on the breadboard. The display works best when powered with 3.3 volts.
The light pin, when connected to ground turns the backlight “ON” while connecting it to VCC turns it “OFF”.
Nokia 5110 display connection
Display - Arduino Pin 1(RST) – D12 Pin 2(CE) – D11 Pin 3(DC) – D10 Pin 4(DIN) – D9 Pin 5(CLK) – D8 Pin 6(VCC) - VCC Pin 7(LIGHT) - GND Pin 8(GND) - GND
Now that we are done with the schematic, let’s move to the code for this project.
Before we start writing the code for this project, first we need to download the 5110 LCD graph library that was made by rinky-dink electronics. The library does most of the heavy lifting and makes it easy for us o use the LCD. Click here to visit the download page and then download the LCD5110_graph zip file. When done, unzip the file to your preferred location and then rename the unzipped folder to something simple like “LCD5110”. Copy and paste this folder in your arduino library folder, then run your arduino IDE.
Click on the file, then on examples and then click on LCD5110. Since we are using the Arduino Mega, under the LCD5110 drop down click on Arduino (AVR) and the open up the LCD graph demo file.
Lets break up the code into bits and explain.
In the code we only have to change a few things. we can see from the comment section above that the RST pin of the display was connected to pin 11 but in our case we connected this pin to pin 12 of the arduino Mega. We also have to change the CS from pin 12 to 11.
The first line after the comment section, the LCD5110 library was included and after that a myGLCD object was created with the numbers being the pins to which the LCD is connected. The last two values in the myGLCD object is the RST and CS values which has been changed as explained initially.
with this done, we move to the setup function. In the setup function, the InitLCD method is used to initialize the display and this method takes in a parameter for the display contrast. The contrast value is between 0-127 and since we didn’t pass in any value the default value which is 70 will be used. Next the setFont method is called which sets smallFont as the display font style is called and lastly, the randomSeed function which is used to initialize the random number generator using analogRead on an unconnected pin as a random input.
In the loop function, on the first line the screen buffer is cleared using the clrScr method. The drawBitmap method was used to draw the arduino logo and this logo is placed in the screen buffer when the method is called. The update method is used to copy the screen buffer to the screen then we give it a delay of 2 seconds before clearing the screen buffer again.
Next a rectangle is drawn using the drawRect method. Lines are drawn in the for loop using the drawLine method which takes in four parameters (x1, y1, x2, y2). The font is changed to tinyFont, then we print text on the screen and the update method is called to copy whats in the string buffer to the screen. A delay of 5 seconds before clearing the screen is inserted.
Most of the functions use in the project have names that are self explanatory, like myGLCD.drawLine needs no explanation for instance as its clear the function draws a line.
Here is the full code for this project. Its an example from the Library named LCD5110_Graph_Demo and how to get to it has been described in the beginning of this section.
Connect the board to your PC and make sure the right board and COM port is chosen. This can be done under the tools menu then Click on upload.
After uploading the code, you should see an output like the one shown in the image below.
Worked right? Yay!!!
See you next time. Don’t forget to leave your comments and questions.
The code is an example for the library so probably no need to attach here again.
You can watch a video tutorial of this topic here on youtube