middle lcd panel free sample

Led video wall screen texture background, blue and purple color light diode dot grid tv panel, lcd display with pixels pattern, television digital monitor, realistic 3d vector illustration

The uLCD-144-G2 from 4D Systems is a low-cost ($25 qty. 100) smart color LCD display board with a serial interface. They are also available from Sparkfun. It looks like a nice alternative to the now hard to find Nokia 6100 LCD breakout boards. It has a TTL level serial interface and a reset pin. An optional uSD card inserted in the display module"s socket can be used to load fonts, images, and play videos in response to serial commands.

In the drawing above, the pins are labeled from the uLCDs perspective with TX and RX pins. Mbed RX goes to uLCD TX and mbed TX goes to uLCD RX. So mbed TX goes to the middle pin on the connector which is the uLCD"s RX pin. The included cable seen below is plugged into the bottom row of pins and plugged into a breadboard using the male header pins for hookup. Note that on the cable silkscreen seen in the image below RX and TX have been swapped to indicate the connections needed to the microprocessor pins.

As an alternative, a two row 10-pin M/F header socket with long PCB leads can be used to make a breadboard adapter by cutting off one row of pins. The header socket plugs into the breadboard and the module plugs into the header socket. The second row of pins could also be cutoff on the LCD module itself, but this would preclude later use of the board’s GPIO pins and 3.3V supply for other projects. For more stable mounting, there are 2mm screw holes at the corners that could be used, but the header socket alone holds it rather well given the small size and weight.

Initially, it would seem that the existing mbed cookbook 4DGL library would work with this module. It turns out that it has a different processor, Goldelox, and a different but similar command set than the earlier 4D Systems displays supported by the 4DGL mbed library. So a fork of 4DGL was required with quite a few changes in #defines for command values and baud rate divisors. Some functions are not available and some now have 16-bit arguments instead of 8. The basic features used in the demo code below work correctly and some additional work on the new library code could add other features. Support was also added for the use of printf by using the Stream base class and providing _putc and _getc virtual functions. With some minor changes (#defines for number of x and y pixels) the library should also work with the other small LCD displays from 4D systems that use the Goldelox processor. The large LCD modules and modules with touch use a different processor.

Video of demo code. A micro SD card on the LCD module is required for images and videos. The display is actually a bit more colorful and clearer than it appears in the video. Demos include text using printfs, basic graphics commands, a simple bouncing ball animation, computing the Mandelbrot set pixel by pixel, a Plasma wave BLIT, a JPEG image, and a *.wmv video clip.

The more complex Mandelbrot and Plasma wave demo code is not listed here for brevity but can be found after the code seen above in main.cpp in the uLCD144G2_demo program with the download link below.

Fork of 4DGL lib for uLCD-144-G2. Different command values needed. See https://mbed.org/users/4180_1/notebook/ulcd-144-g2-128-by-128-color-lcd/ for instructions and demo code.

After some experimentation with delays, the driver library now works up to the LCD"s maximum supported baud rate of 600,000. For extreme overclockers, the undocumented baud rates of 750,000, 1,000,000, 1,500,000 and 3,000,000 are running this demo successfully on the mbed LPC1768 with the current delay setup. On other mbed platforms, it will depend on the processor"s baud rate clock and divisor hardware. The quickest way to find out is likely to be through experimentation. The mbed serial API computes the closest possible baud rate match. The demo starts out with 9600 baud which should work on any platform. After the first demo screen, the baud rate is changed on the display and mbed with uLCD.baudrate(value). If it hangs in the demo with the message, "Change baudrate", that baud rate is not working on the platform. For fast transfers and more bandwidth, most applications should use the highest baud rate that works.

The module now comes with the serial mode firmware preinstalled, so it is not necessary to reprogram the module"s firmware to use these features as shown in the manuals with the special programming cable. When starting a new project in the IDE tool, be sure to select the correct LCD module and "Serial". This means that the display"s special IDE tools only need to be used to convert font, image, and video files and write them to the uSD card. The optional programming cable is not needed to write to the uSD card from the PC.

JPEG, BMP, and other encoded image files could also be stored on a filesystem on mbed such as the SD card, local filesystem, or a USB flash drive. It could be read, decoded, and sent to the display using the BLIT (BLock Image Transfer) command. A fairly complex program is required to decode image files and the RAM buffers needed for decoding use most of the available RAM on mbed, so not much is left for any other purpose such as networking or the RTOS. Information on a student project that ported simple open source JPEG and BMP file decoders to mbed for use on an earlier LCD display is available on the project’s notebook page.

If the LCD display functions are used in multiple threads, or in a main program and an interrupt routine or callback additional steps are needed to insure mutual exclusion when accessing the LCD"s IO hardware. In general, the use of LCD commands in interrupt routines and callbacks should be avoided and all LCD commands should be placed in main. Global variables can be set in interrupt routines that code in main could check to send out any needed LCD commands.

With the RTOS, a mutex synchronization lock from the RTOS should be used to control access to the display in the case of multiple threads. In such cases, I/O devices typically need mutual exclusion locks to avoid problems. For example, one thread could be in the middle of a long LCD display command just at the point when execution switches to another thread (or interrupt routine) using the display. The display could wind up in the wrong state when a new command is sent before the first one is completed. In general, printf also contains non re-entrant code. An mbed RTOS LCD mutex lock code example (demo4) is available using a different LCD with several threads that display data in different areas of the display. If the RTOS is not being used, it is also possible to implement a mutex lock by disabling and enabling interrupts on a processor with one core.

Student projects using the LCD are shown above. They include a Pac Man game using an accelerometer, an IoT Alarm Clock with networking, an iPod-like music & video player, a Nest-like thermostat using a temperature sensor, and a Missile Command game using pushbuttons.

The Hisense U8H matches the excellent brightness and color performance of much pricier LCD TVs, and its Google TV smart platform is a welcome addition. But it’s available in only three screen sizes.

The Hisense U8H is the best LCD/LED TV for most people because it delivers the performance of a much pricier TV yet starts at under $1,000, for the smallest (55-inch) screen size. This TV utilizes quantum dots, a full-array backlight with mini-LEDs, and a 120 Hz refresh rate to deliver a great-looking 4K HDR image. It’s compatible with every major HDR format. And it’s equipped with two full-bandwidth HDMI 2.1 inputs to support 4K 120 Hz gaming from the newest Xbox and PlayStation consoles. Add in the intuitive, fully featured Google TV smart-TV platform, and the U8H’s price-to-performance ratio is of inarguable value.

In terms of design, the Hisense U8H is not as svelte as our upgrade pick, but it’s plenty sturdy and doesn’t look or feel cheap. Two narrow, metal feet jut out from beneath the panel and steadily hold the TV. They can be attached in two separate spots, either closer in toward the middle of the panel or out toward the edges, to account for different-size TV stands. The feet are also equipped with cable organization clasps—a nice touch for keeping your TV stand free of cable clutter. Though the TV is primarily plastic, its bezels are lined with metal strips, providing a bit more durability in the long run. I moved it around my home, and it was no worse for wear, but we’ll know more after doing some long-term testing.

The Hisense U8H has some difficulties with banding, or areas of uneven gradation, where transitions that should appear smooth instead look like “bands” of color (sometimes also called posterization). Like many current 4K HDR TVs, the U8H uses an 8-bit panel rather than a 10-bit panel, which affects the color decoding and color presentation process. This is usually relevant only with HDR video and games. When playing games on the PlayStation 5 and Xbox Series X, I saw a few instances where the content wasn’t rendered correctly and displayed ugly splotches of color on the screen. However, this almost always occurred during static screens (such as a pause menu or loading screen); I rarely spotted it during actual gameplay. Hisense has stated that it would address the problem in a future firmware update, but at the time of writing it was still present. This is a flaw that may give dedicated gamers pause, but we don’t consider it to be a dealbreaker for most people.

Finally, like most TVs that use vertical alignment (VA) LCD panels, the U8H has a limited horizontal viewing angle, which may be a bit annoying if you’re hoping to entertain a large crowd. Our upgrade pick uses a special wide-angle technology to address this.

Display boards in black or white-colored "foam core" (a sandwich made up of two pieces of smooth surface paper with a polystyrene (plastic) middle) or corrugated cardboard are readily available at many retailers ranging between $4 to $14 per board depending on the material.

Standalone displays are a type of POP display that stand independently of common aisle shelves. These displays are usually seen in the middle of large store aisles, also known as “action alleys.”

8. Centers for Disease Control and Prevention. Tobacco Product Use Among Middle and High School Students - United States, 2020. Morbidity and Mortality Weekly Report 2020; 69(50);1881–188865(14): 367.