Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [hd44780]

The HD44780 is a controller/driver IC for dot matrix character LCDs.

The HD44780 is a controller/driver IC designed by Hitachi, for dot matrix character LCDs. It uses an 8-bit parallel bus for interfacing with a microprocessor's databus, while a 4-bit mode is also possible. Today it's most often used with a microcontroller.

This is a typical LCD module controlled by an HD44780:

enter image description here

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Power-up Initialization of HD44780 LCD Module

I'm using an HD44780 clone LCD module a KS0066U. Everything works ok on the module except when I rapidly power cycle the device (on->off->on). For some reason a very short interruption in the power causes the display module to improperly initialize…
mjh2007
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Weird problems with LCD (HD44780 compatible)

I've been trying to interface with a HD44780 compatible display (16x2) for quite a few hours now, but have run into some weird behavior problems which I can't solve. My setup: I'm using the LCD in 4-bit mode (the upper four bits, D4-D7, as in all…
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16X2 character LCD changes contract intermittently and doesn't work with raspberry pi

I've been following adafruits RPi tutorials (and bought their starter kit) I had an Sparkfun LCD Kit lying around. (It has an HD44780 controller LCD, a 10K trimpot and a 16 pin male header) I soldered the header to the LCD, not all that well. I…
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How to program an ATmega32 in C++ to control a LCD?

I'm electronics student. I'm a newbie in programming. I have loved C++ after watching some videos on C++. Am using Atmega32 uC, WinAVR GNU GCC compiler programming tool, 16*2 Hitachi HD4478OU LCD for my project. I have connected 3 switches to PA1,…
Fred
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power HD44780-based LCD with 3.3V by using a negative contrast voltage?

I have a circuit that runs on 3.3V and want to use an HD44780-based LCD with it (which normally requires 5V). The LCD logic and backlight works fine with 3.3V, but the contrast doesn't, so nothing can be seen on it. As the circuit runs on batteries,…
muffel
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How to fix Hitachi HD44780 16x2 LCD garbled display in 4 bit mode?

It often happens that a HD44780 16x2 LCD shows garbled characters during usage. Most help on the web advises for using snubbing techniques to prevent voltage noise such as induction spike. I've done all that but the problem still persists. What can…
Manu de Hanoi
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A small, thin LCD for my device

I've been looking for a good display for the handheld device that I'm building and I've liked the various HD44780-based displays that I've tried. (like for example this one: https://www.sparkfun.com/products/9054) However they don't fit the needs of…
serviceguy
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How does the HD44780 LCD work at the low level?

I'm not asking for a driver specifically, but how exactly it works. I looked up the 2 chips that were in it. HD44780A00 and HD66100F to be exact. I'm assuming one is a display driver? And the other is a segment driver? I guess I'm looking to learn…
user3073
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Interfacing HD44780 compatible LCD display and Spartan 3 FPGA

I've recently bought HD44780 compatible LCD screen (16x2) from eBay. I want to use it with my Spartan 3 FPGA development board, but after I've thought a little about it, I'm not sure that I can use it. The main thing that's bugging me is that the…
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What is the expected lifespan of those 16x2 character LCD?

I want to use the HD44780 character LCD (commonly available in 16x2 characters, though I am using the 20x4 version) in an industrial application but since it will be on 24x7, I am just a bit worried about it lifespan expectancy. I hope it could…
Dave
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driving a 5v LCD with a 3.3v atmega328p microcontroller

Am using adafruit (American hobbyist electronics components retailer) breakout for the max31850 thermocouple amplifier who's data line isn't 5v tolerant. Therefore I want to power my atmega328P @ 12mhz 3.3v. I have been told this is the optimum…
Ageis
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Using HD44780 display without contrast potentiometer

I found tutorial about connecting HD44780 display to Raspberry Pi. In this tutorial there is no contrast potentiometer. Vo is connected to ground. Tutorial author says: In order to control the contrast you can adjust the voltage presented to Pin…
Kamil
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Can't clear HD44780 LCD screen with my own code using STM32F401RE

I have used this library to write something on my LCD screen. When I try to clear it with my own code, it doesn't work for some reason. Clearing text with library works fine. I'm using screen on 8-bit mode. I have checked that the pins are…
togen
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Can HD44780 communicate with FSMC?

I am trying to use FSMC instead of I2C parallel interface to communicate with HD44780 LCD controller. FSMC is connected to SRAM and HD44780 at the same time and the clock frequency is MHz. The clock frequency of HD44780 is only kHz level. Can the…
JellyTea
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Is this HD-44780 compatible display damaged?

I am developing an assembly application that includes a HD-44780 compatible 20x4 display over the I2C bus. After several attempts, I have finally managed to initialize the display in 4-bit mode and show a message, but after a few seconds the display…
Laura
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