Peter Jakab has written a new article on how to adapt character LCD modules for 3 volt operation.
Generic character LCD modules contain an industry standard HD44780 compatible controller, which can operate down at 3 volts. But the modules are usually specified to work only at 5 volts, unless you choose a specific one designed for 3V operation. It is possible and simple to adapt the 5V modules to work on 3 volts.
Getting character LCDs to work at 3 volts - [Link]
praveen @ circuitstoday.com writes:
LCD modules form a very important part in many arduino based embedded system designs. So the knowledge on interfacing LCD to arduino is very essential in designing embedded systems. This article is about interfacing a 16×2 LCD to Arduino. JHD162A is the LCD module used here. JHD162A is a 16×2 LCD module based on the HD44780 driver from Hitachi. The JHD162A has 16 pins and can be operated in 4-bit mode or 8-bit mode. Here we are using the LCD module in 4-bit mode. First, I will show you how to display plain text messages on the LCD module using arduino and then few useful projects using LCD and arduino. Before going in to the details of the project, let’s have a look at the JHD162A LCD module.
Interfacing LCD to Arduino uno - [Link]
by Kalle Hyvönen:
I needed a display for a project of mine and was just going to use a regular HD44780 -based text LCD display, until I spotted some very neat looking TINY OLED-displays from eBay.
The displays are monochrome 128×32 pixel displays with a 4-wire SPI bus and they are around 30x11mm in size (the actual display area is under an inch diagonally!). The exact type of the displays is UG-2832HSWEG04. I found a datasheet for the displays and a datasheet for the actual display controller (SSD1306) and they seemed easy enough to use so I ordered a two of them for just $13.
Using a neat little OLED-display with an Arduino - [Link]
Noureddine Benabadji writes:
Embedded systems frequently use HD44780-type LCD displays as it is considered the most popular alphanumeric display controller. The interface comprises at least 14 pins: eight for data, three for control (EN, WR, RS), two for power supply (Vdd, Vss), and one for contrast (Vre). Configured in 8-bit mode, it requires at least 10 I/O lines (D0..D7, EN, RS). Configured in 4-bit mode, it requires at least six I/O lines (D4..D7, EN, RS). This last case seems usable when using an 8-pin PICmicro. However, 8-pin PICmicros have one pin as an input-only pin.
One wire brings power & data to LCD module - [Link]
EA DIP series displays from company Electronic Assembly provide an uncommon possibility to choose a graphic or a character display without a change of your device´s hardware.
A quality display with a high contrast and an automatic temperature compensation, easy mounting by soldering of pins into a PCB, a display maximally utilizing the module size – without overhangs and mounting openings, compatibility with industry standard graphic controllers (HD44780), low power consumption – all these are the features saying in favor of EA DIP series displays. To these benefits of EA DIP series, we can also add another uncommon feature – a possibility to change a character display for a graphic one without a change in hardware (at types of the same size). EA DIP series consists of several types as you can see in the following table.
Types with the same dimensions, for example the graphic EA DIP122J (122×32) and character EA DIP162J (2×16) and EA DIP203B (4×20) feature the same pinout, that´s why it is possible to use these types into the same PCB (at a modification of firmware of your device and meeting requirements of given types). It provides an elegant way how to create various versions of a product or to maintain a possibility of “upgrade” of your device from a character- to a graphic display.
Detailed description will provide you the EA DIP flyer, as well as datasheets at particular types. A novelty in our portfolio is the type EA DIP203B, which will replace the EA DIP204.
In case of interest in Electronic Assembly products, please contact us at firstname.lastname@example.org.
EA DIP displays – a free hand at a choice of a character or graphic display - [Link]
Embedded Lab has started a new tutorial series on Netduino programming and interfacing. This is the second tutorial in the series where interfacing between an HD44780 based character LCD and Netduino Plus is discussed.
Netduino and LCD interfacing tutorial – [Link]
Ian @ dangerousprototypes.com writes:
We came across Scott Harden’s brief article describing how to control an HD44780 LCD using an Attiny2313. After a number of unsuccessful attempts with other code he found this LCD library written by Martin Thomas for use with AVR-GCC. With a few mods to the code Scott produced the above results controlling his 2×20 LCD in 4-bit mode. The code provides for scrolling and wrapping and can even display Japanese characters. A handy tip for ATTiny2313 users.
ATTiny2313 controlling a HD44780 LCD via AVR-GCC - [Link]
Then I thought about it and I gave it a go. The result is positive! However, there is a gotcha; if you are using LCDs from different manufacturers or different types, the contrast setting might differ, as it did in my example. In order to overcome this, I would suggest putting two potentiometers in your board to adjust the contrasts individually. And don’t forget, you are using one more LCD, meaning more back light current. If you are using a 7805 without a heat-sink, you should re-calculate your thermal values.
Driving two character LCDs in parallel - [Link]
Chris @ PyroElectro.com writes:
There are quite a few articles that I’ve written that feature the 16×2 HD44780 LCD. However I never got the chance to make a simple example of how you can use an FPGA or CPLD with some verilog or VHDL to tell the LCD what to display.
This article will show the process of choosing parts, building a schematic, connecting the hardware and writing the hardware description to control a HD44780 LCD interface and output a few characters to the 16×2 LCD screen. To make things a little easier, we’ll use a familiar board, the CPLD Dev Board that I introduced a few years ago. It’s dated but still a good learning platform!
FPGA / CPLD 16×2 LCD Interface - [Link]
GPS for accurate synchronization and position measurement must use precise clock, so GPS satellites are equipped with atomic clocks. Clock accuracy is amazing ± 1 second in 1 million years. Using GPS module is available not only acquire position, speed, bet also time and date, so in this post I’ll explain how to do it.
Sirf II module has RS-232 interface for communication and it can be connected to PC Com port. Atmega in Arduino board has UART interface. RS-232 basically is the same UART, only zeros and ones voltage levels are different. To match levels MAX232 driver is used. Today’s GPS modules have UART port, so there isn’t any need for MAX232.
Arduino GPS clock using NMEA protocol - [Link]