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FAQ on the topic of
"Board appears dead"
Q1: I just received my new DLP-xxx board and it appears to be dead. What might I be doing wrong?
A: A power source must be selected for the board. Refer to the schematics and confirm that the PORTVCC pin is connected to the EXTVCC and VCC-IO pins if the module is to be powered by the USB port.
Q2: I have a valid power source selected but when I attach my board to the host PC the Device Manager doesn't report a new USB device attached. I ran the serializer and the board has appeared dead ever since.
A: If the VID/PID in the EEPROM don't exactly match those in the driver files Windows won't know how to enumerate the FT2xxBM chip.
To correct this problem you have to reset the VID/PID in the EEPROM. This procedure requires the DLL version of FTDI's drivers to be installed. If the VCP drivers are installed, they must first be uninstalled using the Ftdiunin.exe program located in the directory where the VCP driver files are located on your hard drive or floppy disk. Start by shorting pins 3 and 8 on the EEPROM. Ensure you have selected a power source as described in Q1 above. Apply power to the USB245M by connecting it to the host PC via USB cable. With 3 and 8 shorted, the FT245BM will not be able to communicate with the EEPROM and will use the default 0403/6001 for the VID/PID. Verify the Device Manager reports "FTDI FT8U2XX Device" under Universal Serial Bus Controllers. Remove the short between 3 and 8. Run the program VIDPIDfix.exe (download here) ignoring the read errors. "Search" for the attached board to be programmed and "Open" it. Once Opened, click on "Write Default EE Data". Disconnect the board and verify all is working well again.
If you modified the VID or PID entries in the driver files, don't forget to delete the modified driver files from your hard drive and start with a fresh copy.
Q3: I'm running Windows XP and am having problems getting the drivers installed.
A: Windows XP Service Pack 1 comes with our VCP driver as part of the download. This uses our default VID (0403) and PID (6001). This is because a UK customer got our VCP driver WHQL certified by Microsoft. Copies of Windows XP with recent Microsoft updates installed may also include VCP.
As far as we know there are two possible ways to get around this;
1) To install D2XX on an XP system with Service Pack 1 installed : Make sure that you have a copy of the latest version of D2XX downloaded from our website. Unzipped it into a folder somewhere on your c drive, or (preferably) onto a floppy disk.
1.1) Plug in your USB device and allow it to install VCP by detecting new hardware and following the prompts in the add new hardware wizard.
1.2) Go to the device manager (found in ''control panel'' ''system''). Select view devices by connection from the view menu. You will find our device listed under ''BIOS > ACPI > PCI Bus > USB host controller > root hub > > high speed usb to serial converter > USB serial port (com port number)''.
1.3) Right click the ''USB serial port'' and select ''disable''.
1.4) Right click ''high speed USB serial converter'' and select ''update''.
1.5) A wizard for updating the driver should now appear. Follow the prompts. Choose the option ''Don't search I will select the driver to install'' then select ''Have disk''. Now point the Wizard to the location of the D2XX drivers on your system.
1.6) D2XX will now install successfully. You can check this by selecting ''View devices by Type'' from the ''View'' menu in the device manager. The com port which was listed in (1.2) should now be gone.
Alternatively you can do the following;
2) Program the EEPROM on your board(s) to use a different USB product ID (PID). We can provide you with a block of PID's for use along with FTDI USB Vendor ID. This service is free of charge. The EEPROM is programmed using a utility we provide called FTD2XXST.exe. This utility requires D2XX to be installed, so you would need to do this on a non-XP machine. This will then allow you to load D2XX on an XP machine. (Uninstall VCP using ''add / remove programs'' and install by plugging in the USB connector and following the add new hardware wizard) Note : you need to remember to edit the D2XX .inf file to include the new PID (and VID, if you have one).
Notes:
Don't try to install our drivers over a network. If you are connected to a network we would recommend that you disconnect during installation.
You should only ever install our drivers by plugging in the USB cable, detecting new hardware and following the add new hardware wizard.
You should only ever uninstall our drivers using ''add / remove programs'' from the control panel. The situation described in (1), above is the only exception to this. If you have tried to use another method at any point there is likely the system in question will have driver components left behind in the registry. Let me know if you think that this might be the case. We can send you instructions on how to remove our driver files from the registry by hand. I would recommend that (at least initially) you try using method (1). If it fails, let us know at which point, and the any error / failure messages that you see.
Keith Dingwall
FTDI Support
Q4 : Now I can load the DLL drivers but XP still tries to load VCP drivers every time I connect a board.
A : Some users of the D2XX drivers with FTDI's default VID and PID ( 0403 + 6001 ) have been experiencing problems installing under XP with Service Pack 1. This is due to Windows XP Update trying to automatically install XP certified VCP drivers in place of the D2XX drivers. An application note on this problem can be downloaded by CLICKING HERE ! A program that can fix this problem by reprogramming the default VID / PID to ( 0403 + 6006 ) can be downloaded by CLICKING HERE ! This should be used in conjunction with the latest drivers.
Q5 : I can send only 2 bytes of data to the DLP-USB245M, on the third send the application hangs. It's as if the buffer is only 2 bytes long. What wrong with this picture?
A : You must read the data from the FIFO using a micro (or some other means) or the board will appear dead to the host. The FIFO buffer that receives data from the host is actually multiple 64 byte buffers (62 bytes for data and 2 bytes for USB status). When one buffer fills up it is swapped out with another so that the data is available to the micro and so that more data can be received from the host.
If you send a byte and pause, after a short timeout period the buffer is swapped out so that byte will be available to the micro. If you do this a couple more times without the micro reading any data from the FIFO then there are no more 64 byte buffers available and the host application reports an error. So read the bytes from the FIFO whenever you see the RXF line go and this problem should go away.
Updated 03-09-03
DLP Design
E-mail: 
info@telesys.ru
