HD44780 based LCD displays are very popular for embedded projects because they are cheap, easy to interface, can display characters, consume power lot less than seven-segment displays, and most of the present day compilers have in-built library routines for them. However, the only disadvantage is that they require at least 6 I/O pins of microcontroller. Well, you may ask, isn’t that less than what seven-segment displays require? Yes, that’s true but there are circumstances where you don’t have left enough pins for LCD display.
Why pay for Serial LCDs when you can make your own? - [Link]
Pretty much ever since the iPhone 4 with retina display was launched, resolutions have played a major role in smartphone market. In September, Samsung unveiled Galaxy S II HD LTE, which sports a 4.65″ 1280×720 display. That was the first smartphone with HD resolution (720p). Now there are already a few phones with HD resolution, for example Samsung Galaxy Nexus and LG Optimus LTE. Higher resolutions are not only courtesy of smartphones as “retina” displays are coming to tablets as well. On May, Samsung showed off a 10.1″ panel with resolution of 2560×1600 – resolution that’s only seen in high-end 30″ monitors.
Toshiba Releases 6.1″ Display with Resolution of 2560×1600 - [Link]
The MAX7219 does all the control and refresh work for you in driving either an 8×8 matrix display or 8 x 7-segment displays (usually these also have a dot so its really an 8-segment display) – 64 LEDs total. All you have to do is send it serial commands via the 4-pin SPI interface and it will auto-magically take care of the rest. Wiring is simplified as well, you only need to set the current level for all LEDs with a single resistor instead of 8 and you can also dim the entire display digitally. It’s a thru-hole chip so you can use it in any breadboard, perfboard or other project, although if you’re soldering it in, we suggest using a socket.
MAX7219CNG LED Matrix/Digit Display Driver – MAX7219 - [Link]
Brian writes… [via]
I found these electromechanical vane displays on eBay and accidentally won them. So, here they are! These are seven segment displays. Each segment is painted a bright yellow and fluoresces under UV light. The segments do not actually draw any power except when they are moved. Behind each segment is a solenoid that flips the segment on or off. Several units are then daisy chained together to form larger numbers. Watch the video below to see it in action and be sure to check out the image gallery.
Staver Electromechanical 7 Segment Vane Display - [Link]
Using VFD display with Arduino – [via]
Summer of 2010 I picked up an Arduino board from adafruit and took some time to walk through all of the tutorials available with it. Since then I have spent most of my time on other projects including my bachelor’s. Recently I have obtained the Motor Party Pack, LoL Shield Kit, and a 20×2 VFD (Vacuum Fluorescent Display) to go with the original board so my interest is sparked again. I have found that the Motor Party Pack and LoL Shield have adequate instruction and tutorials, but the VFD is lacking in beginner level instructions to get started. As such I have decided to write a tutorial for the 20×2 VFD available through adafruit.
The adafruit VFD is made by Samsung and is model No. 20T202DA2JA, this is really unimportant though as adafruit is nice enough to link you to the spec sheets for both the module and the controller chip. What you would be looking for is the pin-out found on page 4 of the module controller sheet.
Using VFD display with Arduino - [Link]
An Atmega16 microcontroller and a few other parts displaying a text on some 14 segment display modules. Programmed using a jtagICE clone.
14 segment display text with Atmega16 microcontroller - [Link]
András Veres-Szentkirályi found an old CGA monitor and wondered whether it could be repurposed for use with an Arduino. He noted that CGA monitors use inexpensive DB-9 connectors, the signals are TTL (0-5V digital), the
clocks are in the range of cheap microcontrollers (HSYNC is 15,75 kHz, VSYNC is 60 Hz), and yet 640 by 200 pixels can be drawn in 16 colors.
He dug through old technical data on CGA and worked up the necessary code, posting the results on his blog.
He believes further development is possible to clean up the timing, so his next step will be to use plain AVR C/C++ code to avoid Arduino overhead allowing finer control over the timing. He would also like to create a character map in the Flash (PROGMEM) and code up a library that would allow the display of text or simple graphics.
Arduino driving CGA display - [Link]
The objective was to create a system that could display written alert messages and at the same time equip the electric weelchair with sound and light capability. The messages would be something like “Thankyou”, “Attention” and “Carefull wheelchair”.
Weelchair Project – [Link]
TDK Corporation has started mass production of a new translucent passive matrix organic electroluminescent display with QVGA resolution. The UEL476 display is fabricated using thin-film technology with an organic material that emits light in response to an electric current. It features high brightness, a wide viewing angle and other characteristics that make it very easy on the eye. [via]
TDK rolls translucent organic electroluminescent display – [Link]
AdaFruit recently released a sweet little TFT display that I was dying to hook up to a netduino: the display features a resolution of 128*160 pixels, is capable of showing 18-bit colors and has a microSD card reader on the back of the breakout board. As usual, Limor wrote a nicely detailed Arduino tutorial showing how to connect the display and how to write sketches to drive it.
The Arduino driver relies on the ability of the Atmega168/368 to toggle digital lines extremely fast, which does not work well on the netduino due to the latency introduced by the .Net Micro Framework: even when configured to use hardware SPI, the Arduino driver constantly toggles a data/command output line, rspin below, which would be unbearably slow on the netduino if the same method were applied.
The netduino has one advantage over the Arduino: it has plenty of RAM. So, instead of toggling I/O lines slowly all the time and using next to zero RAM, the netduino driver allocates a 40K buffer corresponding to the resolution of the display in 12-bit depth colors (16 bits per pixel) and leaves the ST7735 in ‘data’ mode upon initialization.
Drawing always happens on the internal buffer first. Then, whenever the actual display needs refreshing, the display I/O operations are performed using hardware SPI, blasting the entire 40K buffer. It may sound crazy but using this method on the netduino is faster than refreshing a single pixel while toggling an I/O line!
Driving an Adafruit TFT Display with a Netduino – [Link]