Raj from Embedded Lab shows in his latest tutorial guide how to implement adaptive brightness control to seven segment LED displays for optimum readability in all illumination conditions. The technique has been demonstrated by constructing a temperature and humidity meter that adapts the brightness of the seven segment LED displays to the surrounding lighting conditions.The project uses a general purpose LDR to sense the surrounding illumination and MAX7219 to drive the LED display.
How to implement auto-brightness adjustment to seven segment LED displays – [Link]
The following display features eight 7-segment displays arranged in two rows of four digits. The on-board MAX7219 driver enables you to easily add eight 7-segment LED displays to your project using only 3 I/O pins of microcontroller. The major advantage of using this board is the time-division multiplexing operations required for continuous refreshing of the display digits are performed by the MAX7219 chip, thereby keeping the microcontroller free for doing other pressing tasks. It is suitable for displaying two variable values simultaneously in a project, such as displaying temperature and humidity, or current and voltage, etc.
8-digit seven segment LED display with SPI interface – [Link]
Karan Shah writes:
LG Display has announced a 5-inch, full HD LCD panel for smartphones – the highest resolution mobile panel to date, giving a clear indication that the 720p display on your current top-end smartphone won’t reign supreme for long. This new, 5-inch Full HD LCD panel is a step forward from the existing mobile display technology and is based on AH-IPS (Advanced High Performance In-Plane Switching) technology. It features a 440ppi and 1920×1080 resolution, providing, for the first time, Full HDTV quality on a smartphone. We had first carried a story about AH-IPS displays, way back in May 2011 and LG had announced then that they were indeed developing AH-IPS panels for smartphones. Here’s how AH-IPS improves on the existing technology.
LG announces 5-inch – 1080p displays - [Link]
We incorporated among standard stock types the dot matrix LED display Kingbright TC12-11 with the height of 30.6mm. Hyper red color (630nm) and a high luminous intensity provide a contrast image.
TC12-11SRWA with 5×7 dots can be conveniently used especially in indoor applications, where it will provide an excellent readability at various ambient light conditions. Display can also be used for outdoor applications, excluding places on a direct sunlight, where the display legibility can be substantially decreased.
High light output, typically 82mCd/10mA and white diffused lens ensure a very good visibility even from higher viewing angles. Display features almost a linear luminous intensity / current characteristics in a range from 0 to 20mA, that´s why it is fully usable even for low power applications. Similarly like almost all dot matrix displays, even TC12-11 is designed in a way that when placed in a row, we will obtain a continuous row with homogenous spacing between dots. That´s why it is possible to display even symbols wider than 5 points and naturally a moving text.
TC12-11 has a common cathode (in a column), available are also versions with a common anode (in a row) and also various colour versions.
Universal 1.2″ LED dot matrix display - [Link]
uLCD-14 replaces the previous model uLCD-144. The new type remains a full software compatibility, that’s why if you already have an application designed for uLCD-144, you can use them without any modification.
The only main change is the connector, instead of the original 1×9 THT pin header a new 2×5 SMD pin header is used with an added +5V output through a protection schottky diode. The new uLCD-14 module, also marked as uLCD-144-G2, features the same excellent properties like other members of uLCD family.
Properties of the module are mainly determined by the used Goldelox chip, able to work in a slave, as well as stand-alone mode. It is also possible to use the 4D-Visi graphic development environment, considerably simplifying and accelerating a development of graphic applications. A detailed description of features common to all 4D Systems modules you can find in our article. Detailed information will provide you the uLCD-144-G2 datasheet.
New 1.44“ intelligent displays from 4D Systems already in stock - [Link]
Seven segment LED displays are a very popular mean of displaying numerical information and finds application in front panel display boards of microwave ovens, washers and dryers, digital clocks, frequency counters, and many other gadgets. Compared to the LCD displays, the seven segment LED displays are brighter and provide a far viewing distance and a wide viewing angle. However, the downside is they are resource-hungry. It requires at least 12 I/O pins of a microcontroller to drive a standard 4-digit seven segment LED module. Consequently, their use with low pin-count microcontrollers (such as PIC12F series) is not practically feasible. Here’s a solution for that. The following 4-digit seven segment LED module features a serial interface that requires only 3 I/O pins of a microcontroller and provides full control of all digits and decimal points .
Serial four digit 7-segment LED display module - [Link]
New intelligent display eDIPTFT70 from Electronic Assembly provides all what its smaller relatives and something in addition – the size.
With the 7” size and an 800 x 480 pixels resolution, it can display a relatively considerable amount of information. Similarly like other member of family eDIP (eDIPTFT32 a eDIPTFT43), even eDIPTFT70 eliminates the need of demanding and time-consuming programming at pixels level.
All the control of the display is done on commands level, thus to display text, graphics and many other symbols is exceptionally easy and simple. Control by commands substantially accelerates development and shortens the time to market. At an application development it is possible to use predefined functions, symbols and geometric functions, bargraphs, frames, buttons and many other. In general eDIPTFT70 offers almost the same functions like other eDIPTFT family members, including almost immediate start within a few 1/10 of second.
Single +5V supply, analogue touch panel with a variable raster and software-dimmable backlight brightness contribute to the versatility of usage. In many of applications also 80 various short jingles for audio feedback can be useful. Even eDIPTFT70 contains 3 communication interfaces – RS232, I2C and SPI, that´s why it can be connected to virtually any device. Further information will provide you the eDIPTFT70 datasheet.
New 7“ eDIPTFT70 display – when the size matters - [Link]
Sergei Bezrukov writes:
Controlling big LED displays that use several LEDs for lighting each segment is a certain challenge. The problem is that the voltage drop on display segments is well above the maximum voltage of microcontrollers. This project describes an approach to this problem based on source and sink drivers TLC59210 and TLC59213 manufactured by Texas Instruments.
Big LED clock with automatic brightness control - [Link]
Sergei Bezrukov writes:
This is a shortened translation from Russian of my article published in Радио (Radio) magazine, no. 8 (2010) pp. 21-23. The voltmeter is designed for controlling DC voltages at the output of a dual bipolar power supply. It not a universal instrument, since its input resistance does not exceed 40K, which might be too low for some measurements. However, it is perfectly fine for power supplies and does not noticeably load their output. The range of input voltages is 0 to 24V for positive supply and -24V to 0 for negative one.
The voltages are sampled every 300 msec and displayed on a 9-digit LED display. Only 8 digits are used, the middle digit slot is always off and serves a a separator between negative (on the left part of display) and positive (on the right one) readings. The unit provides a 0.01V resolution. For small negative voltages (not exceeding 10V in absolute value) a leading minus sign is displayed. For positive voltages a leading zero is suppressed.
Voltmeter for bipolar power supplies - [Link]