Frequently Asked Questions
Q: I have a Mini2440 with 64M Flash and want to get one with 128M / 256M/ 1G. Will I have any problems with my software?
A: Yes, a little. The 64Mbyte NAND Flash has a read/write block size of 512 Bytes and an erase block of 16K. The 126, 256, 1024M parts have page read/write size of 2K and erase blocks of 128K. So, 128, 256, and 1024 (1G) are identical in usage. The latest versions of u-boot test the environment and pass boot parameters so Linux knows which memory it is using. In other situatiuons, like Windows CE6.0, images are generated specifically for the two memory paramaters. Only two images are needed: one for 64M, and one for all others.
Q: I am trying to use the serial port on the Mini2440 and getting nothing! What is wrong?
A: The Mini and Micro2440 DB9 is wired as a DCE, like a MODEM, not a PC. Use the cable that came with your system, not a null modem cable. In other words, the same kind of serial cable you would use with a printer.
Q: I have a Micro2440-SDK and the NAND/NOR switch isn't working. It is always in NAND mode. Is it broken?
A: Well, maybe. But the Micro2440 "stamp" module has a jumper you should remove before jumping to conclusions- the only one on the board. It is used to switch modes in custom designs with no external switch.
Q: What is the power supply controversy?
A: The nice little 5V 2A power supply, Youhong model 1201, turned out to have counterfeit UL and CE markings. These were shipped by us for a while and are shipped by virtually all eBay sellers and are subject to hold and confiscation for destruction by US Customs. If there had been no markings, they would have been OK for the US. Valid CE is required for most of Europe. We have new supplies that are certified. If you bought from Watterott in Europe, they used a German power supply and there is no problem.
Q: I have a new Mini2440 with LCD. When I power on, Linux launches, but in Chinese! How do I change it?
A: There are several tools that look like they should change the language but only one will work. Select the tab that looks like a bunch of colored baloons. There is a red icon easily mistaken as a beach chair. It is a Chinese PRC flag, red with yellow star, waving horizontally over a Union Jack. The Chinese characters say "Language Selection." Tap this icon and choose English or Japanese. The Linux will restart when you are done.
Q: I have a system over a year old. How can I use the newer FriendlyARM OS images? They either won't load or something crashes, including Vista!
A: To load the latest kernel and file system you will need to update the boot loader (supervivi) in the NOR Flash. Here is a PDF on how to do it JTAGingTheNor.PDF and here is a download of the newest binaries including the latest supervivi ViviJTAG.ZIP. Note that there are versions for 64M and 128M. New Mini2440's all have 128 MBytes or more of NAND Flash. The 64Ms are getting hard to find. The boards were designed to grow with the increase in Flash density and the chips fit with no changes. We will migrate painlesly to 256 MByte versions when the higher density chips get common. RAM will stay the same. Does it really matter that much? Not when the SD card slot can accomodate 32 GBytes!
Q: I have an SD card that is not recognized by the Mini software. What is wrong?
A: We have reports that SD cards that were initialized on a Mac (which is UNIX) work fine and those initialized on Vista fail.
Q: I am trying the new software and my video is not working right. What is wrong?
A: All the new Mini35 ship with a Toppoly 3.5" LCD and the older units all have NEC 3.5" LCD's. They use different timing. The software releases included images for each. Try switching to the one the ends with a T instead of an N.
Q: I need to do floating point math and use transcendental functions but the S3C2440 on the Mini has no math coprocessor. What kind of speed can I expect?
A: People using Linux or Windows CE with software floating point get 4 to 8 MFLOPS - Million Floating Point Operations Per Second, like multiply, add, divide - which is pretty good. The ARM has a single cycle barrel shifter that can shift any number of bits as part of any machine instruction. This aids greatly in efficient software floating point.
Q: I have been looking at all the Mini2440 systems on eBay. Is there anything wrong with them?
A: With the exception of counterfeit power supplies, we have had no reports of problems and in fact we work with a couple of the eBay sellers in China when someone in that part of the world needs quick delivery or we are out of stock. But, there are differences. First, you will probably get a Chinese DVD/CD which means all the docs are in Chinese and many of the file names too (or you could luck out and get one of the sellers who has copied our translated DVD). You can handle most of it with google translate if you have to. Here are the main differences. Look closely at the description. At this time someone has dumped a large number of the pre-August 2009 Mini2440 with 64M NAND onto the eBay sellers. We are pretty sure it wasn't FriendlyARM since we offered to take all remaining 64M systems for an OEM who doesn't need more NAND. If they have NEC 3.5" displays, then they are pre-August 2009 64M systems. All new Mini2440 with 3.5" have LCDs from Toppoly. If under the software they list three different compilers, then the CD is from the Spring of 2009 and pre-dates the FriendlyARM Linux 2.6.29 with Qtopia 2.2.0. You will have to download all new software or an ISO image of the DVD. There is nothing wrong with these older systems. Eighteen months ago they were $149 and they have the same 405 MHz clock and the same processor. Just note that the 64M systems are priced the same as 128M systems on eBay. When they drop by $10 or $20 they will be a bargain and very close to what the seller paid for them.
Q: What about the pricing. It is around $85!
A: The pricing is reasonable. When you add the listed shipping cost it is +- a few dollards of our pricing with shipping, and if you live outside the US you might even get a better overall price. Plus most of our translated documents are free on our downloads page. However, make sure you are getting the new Mini2440 with 128M NAND and the Toppoly LCD (if you get the 3.5"). If you are looking at a bundle, read the item below "Why does FriendlyARM sell a wifi that doesn't work?" See an advantage for you to buy on eBay? We can recommend Esky-sh. He stays on top of the product line and searches out or designs very nice accessories and is more than a simple reseller. Plus he has a comprehensive forum with many members.
Q: How can I calibrate the touch pad if it is so uncalbrated that I can't open a terminal or select the calibration task?
Boot with a generic USB mouse attached. It will be recognized and will work at the same time as the touch pad. Select the tools tab, then the calibrate icon. Don't use the mouse to calibrate! Calibration needs the values from touching the screen with a good stylus.
Q: How much power does the Mini2440 use?
A: With 5V input, the Mini2440 + 3.5" LCD uses 600mA peak (3 Watts), 440mA when Linux is idling and the backlight on, 290 mA when Linux is idling and the backlight off. When Linux has shut down, the system is waiting for a reset at 250 mA (1.25 Watts).
A Mini440 with no display runs between 200 mA and 300 mA. Adding SD cards has a small effect. USB devices like wifi can increase the load quit a bit.
Q: Will the Mini2440 handle full size SDHC SD cards?
A: Yes. The Linux drivers meet the spec for huge storage volumes to 32 gig.
Q: Can I use something bigger, like a VGA display, during development?
A: Yes. There is a Mini2440/Micro2440 VGA adapter with a cable just like the LCD and a VGA connector. It can be mounted in place of the LCD or anywhere convenient. It will handle 1024x768 and other sizes.
Q: Why can't I get the Ubuntu ARM distro to run on my Mini2440?
A: The Ubuntu ARM Distro is based on the ARMv5 instruction set (and ARMv7, Cortex, etc. for netbooks). The S3C2440 ARM920T uses the ARMv4 instruction set. You would have to compile the Ubuntu distro from scratch and solve all the problems that arise. Mini6410's, available soon, will easily run these distros.
Q: Do I have to use the Linux that comes loaded on the board?
A: Of course not! Check the Downloads page to start. There are several alternatives and there will be more. There will also be more consistency now that Mini2440 support has been merged into mainstream Linux.
Q: I have built my own Linux but it won't load and I can't program the NAND. What is wrong?
A: Probably a million things, but if you didn't use the latest Mini2440 branch, you could have NAND problems. The new 128M NAND uses 2K blocks and 128K erase blocks. Your bootloader has to handle this correctly. Supervivi has two versions -64M and -128M.
Q: Can I work with Windows CE by myself?
A: You can write applications for CE with EVC, Embedded Visual C. To change the features of the runtime OS package you can use the BSP (Board Specific Package) with Windows CE 5.0 Platform Builder. Microsoft has an evaluation version that will run for 180 days. For CE 6.0, there is also an evaluation version plus Visual Studio 2005, since Platform Builder 6.0 is a plugin for Visual Studio 2005. For full unlimited software, the tools are about $1,000 and licensing is $3.50 to $5.00 for the most basic licensed runtime and increases (but not much) with the number of Microsoft resources you include in your runtime package. The tools have to be bought from a reseller like BSquare, or Avnet, or Future. You can get all the evaluation tools from Microsoft on DVD (5 of them!) for free. Using them with Vista requires several patches and service packs and a confusing sequence of downloads and installs. XP is a better choice for development. They also work on Windows 7, which for some reason requires the Vista patch.
Q: How can I load the OS image files from Windows?
A: There is a utility called DNW on your DVD or the downloads page. It is an executable and does not need to be installed. Here are directions for loading Linux kernels and file systems from Windows. DNW Linux Load PDF.
Q: How do I make connections to the board for my project?
A: The Mini2440 Cable/Connector Kit is a bargain with 10 complete cables and connectors and mating sockets.
Q: Why does FriendlyARM sell a wifi that doesn't work?
A: The RT6656 is fully supported by Windows CE. Most people have not tried the Windows CE sample included on the DVDs because it is in Chinese. VIA does not make new drivers for Linux available. They are being worked on. Use a WN321G (TP-Link, RAlink chip set) or equivalent with Linux. Late news. Word is that Linux 2.6.32 supports the VIA chip.
Q: What are the "OEM" versions of the FriendlyARM parts?
A: OEMs (Original Equipment Manufacturers) have begun production of a product using the Mini or Micro2440 and buy in volumes like 50 or 300 or 5000 a month. They don't need the power supply, Ethernet, USB, Serial, and JTAG cables, nor the DVDs, etc. They get a price savings for both the stuff they don't need and the much lighter load for shipping. Pricing is on a company-by-company basis depending on their volumes and customising needs.
A: Power over Ethernet is a scheme that uses a quirk of the Cat5 cable and has the great advantage of powering remote devices over the same cable used for communication. Ethernet on Cat5 leaves 4 wires unused. PoE uses these in pairs to provide power much like USB can power a device. Pins 4 and 5 are positive and pins 7 and 8 are negative or return. There is a standard that allows up to 67 volts and 70 watts and requires "smart" supplies and powered devices that communicate by changing the resistance of the load. Most PoE power supplies provide 48V or 24V (or 12V for shorter runs). Do it yourself PoE is 48 volts or less. In most of the US, this is below the levels that require an electrician or inspection. Note that any crossover cables will swap the polarity! The solution to this potentially disasterous problem is to always put a bridge on the input to the regulator for any powered device, then the polarity will not matter. Texas Instruments and many others now make inexpensive chips for wide range DC/DC converters for PoE. The whole converter fits in a tiny space with awesome power output. We supply 12V and 24V power supplies with built in PoE injection, and very inexpensive injector/splitter hardware.
Q: I have a Mini2440 and 7 inch LCD. Why is the touchpad difficult to use with the stylus?
A: The Samsung S3C2440 chip on which the Mini2440 is based has 10 bit A/D converters. A 10 bit convereter has 1024 distinct outputs. The 7 inch LCD is 800 pixels wide. There are elctronic offsets at the left and right edge that can leave the A/D with a usable span of less than 800. This means there is less than one count per pixel position and we see this as noise in the signal. A driver with improved digital filtering could help. A small PCB with op-amps for gain and offset to produce full span for the A/D could be rigged up if absolutely necessary. We are working on driver improvements. It looks like the drivers available have been extended from code meant for small cell phone screens, and they need reworking. Early experiemtns are very promising. Note: The Aug 23 build of the Linux 2.6.29 kernel and Qtopia greatly improved the touch pad response. Also note that Windows CE6.0 somehow eliminates the jitter and works rather well with the 7".
Q: What happens when a doe sees a dangerous predator near her fawns?
Q: Can I download a picture of that amazing cat for background on my display?
A: Yes you can. Right here.
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