It can be used to display data acquired from sensors, create an interactive menu, or as a debugging tool. You can even create your own custom characters to display! This will require 6 digital output pins from the Uno to drive the LCD 4 pins for data and 2 pins for control. It uses an industry standard Hitachi controller so the basic operation is similar across different vendors that sell them.
|Published (Last):||18 May 2015|
|PDF File Size:||18.23 Mb|
|ePub File Size:||10.16 Mb|
|Price:||Free* [*Free Regsitration Required]|
It can be used to display data acquired from sensors, create an interactive menu, or as a debugging tool. You can even create your own custom characters to display! This will require 6 digital output pins from the Uno to drive the LCD 4 pins for data and 2 pins for control.
It uses an industry standard Hitachi controller so the basic operation is similar across different vendors that sell them. They have both a 4-bit parallel and an 8-bit parallel interface. A pinout of the LCD is below. The Register Select RS on pin 4 is used to either send commands when it is low, or data when it is high. The LCD has the capability to execute a program and display information which justifies the need for this pin.
However, we will only be writing to the LCD, so we can ground this pin which will place it permanently in write mode. The next eight pins are used to send the data. Pins 15 and 16 are the anode and cathode of the LED backlight, respectively.
We will need to use an external resistor in series with this backlight to limit the current. Otherwise, the LED could burn out. The LCD has a timing diagram that must be followed to be able to send commands and character data. There are also set-up and hold times which also must be taken into account. This allows the signal levels to settle and ensure that pins are sampled at the right time. The diagram below shows the timing diagram for sending a command to the LCD in 4-bit mode.
If we want to send the command to clear the display, we have to send upper nibble on the data bus and then send lower nibble on the data bus. The 8-bit ASCII equivalent is 0x30 or , so we would send on the data bus and then The library is simple to use and allows us to input the specs of the LCD such as the number of columns and rows, and whether to use a 4-bit or 8-bit interface.
We can also send data and up to 19 different commands. Please watch the video below if you are using Modulus. You should have 6 jumpers: one on pins 4, 6, and Pins 4, 6, and of the LCD will connect to Uno pins 2, 3, and , respectively. If you are using a breadboard, a high-level schematic is shown below. If you are using a breadboard instead of Modulus, place the breadboard in the bottom storage compartment to limit the length of the jumper wires.
You will need two male header pins to mount the test-lead clips on the breadboard side. Software Once the wiring is complete and the FuelCan is powered up, we can now load the sketch onto the Uno. The sketch is below. The LiquidCrystal library contains nineteen different functions that you can use.
We even display a custom character on the LCD! Please do not purchase these products unless they will help you with your own projects.
How to use a 16×2 character LCD with Arduino
Non-LED backlights often require higher voltages I. Mode selection[ edit ] Selecting 4-bit or 8-bit mode requires careful selection of commands. There are two primary considerations. First, with D3-D0 unconnected, these lines will always appear low 0b to the HD when it is in 8-bit mode. Second, the LCD may initially be in one of three states: State1 8-bit mode State2 4-bit mode, waiting for the first set of 4 bits State3 4-bit mode, waiting for the second set of 4 bits State3 may occur, for example, if a prior control was aborted after sending only the first 4 bits of a command while the LCD was in 4-bit mode. If in State3, the LCD will latch the value 0b into bits , and then execute a random command based on the unknown to us values in bits , after which it will either be in State1 if the unknown bits happened to be 0b , or State2 if the unknown bits were anything else.
Hitachi HD44780 LCD controller