5.7 Inch QVGA Touch Screen LCD Kit - NXP LPC2478

Editor Review

Ease of Set-Up:

Documentation Completeness and Clarity:

Hardware Completeness and Quality:

Sample Projects/Tutorials:

Meets Expectations:

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Overall rating:

Time to Complete

Prerequisite Skills

C/C++ programming experience helpful. Experience with FreeRTOS (real-time operating system) or another RTOS helpful.

What We Liked

Excellent hardware, good software tools.

What we Didn't Like

Lack of tutorials to start, but FDI improved during this review and provided two additional exercises, now part of the kit.

Full Review

Future Designs, Inc. (FDI) has combined one of its LPC2478 ARM7TDMI-S microcontroller boards with an ARM Carrier board and connected the pair to a 5.7-inch QVGA liquid-crystal display (LCD) with a touch screen. The complete package serves two purposes. First, engineers and programmers can use the board-set as the target for their own development work. Second, developers can use the kit to help them understand the type of custom-engineering work FDI can perform. I belong in the first group and approached the kit from that perspective. I recommend the kit as a demonstrator but digging into the code to do useful things will take some work, as I'll explain.

The kit took little time to set up and operate, even though it didn't come with an introduction or start-up guide.  I plugged in the accompanying USB memory stick and applied power.  A pre-loaded demonstration created an FDI "splash" display followed by on-screen touch controls for six demonstrations that let me draw on the screen, view current time, temperature, and date, see a ball on the display respond to accelerometers, and so on. If you want to do development work, things get a bit complicated. Even after going through the tutorials I doubt I could understand all the FDI software and go on to create a useful application without a lot of work.

FDI included three manuals with the kit: the "μEZ Software Quickstart Guide," the "Touch Screen LCD Kit Users Manual," and the "SOMDIMM-LPC2478 Users Manual." (It turned out the latter manual included start-up information and an exercise that shows how the computer can communicate with a PC. This information should go into a separate document so kit users find it right away and read it first.)

The short "μEZ Software Quickstart Guide" explains the levels of software used by the ARM7 MCU and how they interact, starting with an application and going down to the hardware through an operating-system abstraction layer, μEZ subsystem drivers, and a μEZ hardware-abstraction layer. FDI uses the FreeRTOS operating system in this kit. I downloaded the μEZ project files (now ver. 1.05) from the SourceForge Web site and unzipping the files into a working directory. FDI provided a table that shows the μEZ file structure and file locations, which can help you locate files and folders. I like that type of file "map" in a kit. (By the way, the people at FDI pronounce "μEZ" as muse, which is easier to say than micro-ee-zee.)

Next, I downloaded and started to install the Rowley CrossWorks CrossStudio for ARM tools available with a 30-day evaluation license: www.rowley.co.uk/arm/index.htm. I had to wait a few hours to get a activation key from Rowley before I could proceed with the complete installation. The software guide explained how to install a generic ARM support package and an NXP LPC2000 support package. If you want to use the kit beyond the 30-day evaluation period, Rowley offers several unlimited license types, from Personal ($US 150) to Commercial ($US 1500).

The kit included a Segger J-Link Lite debugger/flash-programmer pod that provides communications between the target ARM MCU in the kit and the Rowley IDE. A single exercise in the manual explains steps used to build the demo code, download it to the kit, and run it. But this process simply reloads the original demo code, so the new code works just like the original code. You can use this exercise to experiment with the Rowley IDE and use some of its debug capabilities. But after that exercise, you're on your own. FDI didn't provide any tutorial information that explained how do other things with the kit. So, I asked Kent Lowman, director at FDI, "What does a developer do next to learn how to use the kit? The lack of some hand-holding steps might cause people to give up."

I take an "I don't know much" approach to kit reviews and look for tutorials or experiments that help me (and you) understand how to use a kit. Lowman and Lysle Shields at FDI put together additional information in a "μEZ Software Quickstart Guide: Adding Icons to the Desktop and Using the Touch Screen LCD." You should now find that document on the FDI Web site and included with kits.  The new information will give you a better idea of what you need to understand and do to put new graphics on the LCD and use the touch-screen controls.

If you have experience with the FreeRTOS software, control of LCDs, and use of USB and Ethernet ports (if you need them), you can jump right in. The hardware abstraction layer FDI provides offers a bit of a head start, as does the 148-page "μEZ Software User’s Guide," available on the FDI Web site.  NXP Semiconductors, the supplier of the LPC2478 ARM MCU, created a Simple Window Interface Manager (SWIM) that FDI uses extensively to control the QVGA LCD. For references to the SWIM information, see the "For further reading" notes at the end of this review.

I went through the additional graphics and touch-screen instructions step by step and ran into a few snags, which FDI has "ironed out" in its latest software and the newer version of the kit.

The icon-substitution steps worked well as did the touch-screen exercise. Each section includes descriptions of what happens in the code. This is good information that I hope FDI expands to include more details. FDI has more documentation and schematic diagrams on its Web site.

Although I had to stop after the pre-programmed demonstration so FDI could create a couple of tutorials, I liked the kit and found it easy to work with. Instructions were clear for the most part and I bet FDI will continue to revise and improve instructions to remove minor ambiguities and places that might confuse a user for a moment.  It will still take time to develop enough experience with the software to use the kit to do practical work, though. A few simple sample projects would help guide engineers through the steps.

After working with this FDI kit, I offer several suggestions:

1.  You might need to obtain the latest J-Link driver software from Segger. When I tried to build the new code from FDI, I received an error message, "The location of the JLinkARM.dll has not been specified."  I went back to the original Quickstart Guide and determined how to specify a path to the .dll file, but it had gone missing. So, I downloaded the J-Link software from the Segger site, installed it, found the .dll file (now ver 4.14) and specified the path for the J-Link pod. (The Segger site did not list the J-Link Lite pod separately.  Just use the provided J-Link package and you'll get the files and software you need.)

2.  Lysle Shields at FDI suggested when I used the Rowley IDE, I should go to the Target Properties window for the J-Link pod, and set the Loader property "Erase All" to "Yes." By erasing all the flash-memory contents, you remove any bits and pieces of code or data left in the flash memory from a previous experiment.

3.  I also saw an error message, "Cannot connect to J-Link via USB..." I moved the USB connection to the J-Link Lite pod from a USB port on my monitor to a USB port on my lab PC, which solved the problem.

4.  Be sure to "connect" the Segger J-Link Lite pod to the Rowley IDE. Go to: Target-->Connect and select the Segger J-Link from the list.

Kit Contents:

ARM7DIMM processor module, ARM Carrier board, 3-5 LCD Carrier board with 5.7-inch QVGA LCD, Segger J-Link Lite (LPC Edition) debugger/flash-programmer pod, USB memory stick, power cube, USB cable, Segger cables, Ethernet cable. Documents as described in the review.

For further reading:

"SWIM: NXP's basic graphics library for LPC products," AN10815. NXP Semiconductors. www.nxp.com/documents/application_note/AN10815.pdf.

Download the Zip file at: www.standardics.nxp.com/support/documents/microcontrollers/zip/an10815.zip to obtain a complete SWIM manual, documentation, and code.


 

Samples & Tutorials

The kit included a sample exercise that simply rebuilt and reloaded the preprogrammed demonstration software. During this review, FDI provided two additional exercises that replace an icon and demonstrate touch-screen response.

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