"Tsvetan Usunov" <tusunov@my-deja.com> wrote in message
news:dd52331e.0403070246.39fb6845@posting.google.com...
> > I have never experienced this. We sold about 750 units of our product
using
> > this chip and have never experienced this. I'd say it is a design/PCB
layout
> > fault.
>
> the crystal is placed next to IC, with very short tracks, surrounded
> by GND
> where is our failt? we did such routing to hundreds of other designs
> that you didn't experienced such problem may be just that us used
> another batch of ICs or something else.

Is that groundplane directly connected to the capactirors and pin 29?
What value of caps did you use (most made error is a too small value)?

> Sometimes ICs don't behave as per their datasheets you know ;)

I know.

Meindert

> I have never experienced this. We sold about 750 units of our product using
> this chip and have never experienced this. I'd say it is a design/PCB layout
> fault.

the crystal is placed next to IC, with very short tracks, surrounded
by GND
where is our failt? we did such routing to hundreds of other designs 
that you didn't experienced such problem may be just that us used
another batch of ICs or something else.

Sometimes ICs don't behave as per their datasheets you know ;)

Two months ago we had complain for our PIC-MCP programmer that "it
doesn't connect" to MPLAB - it was strange as we do 100% control to
all our devices, so we called them back for review. We received boards
and they worked at our place! But after more extensive tests we found
that these two devices doesn't work if the ambient temperature is
under 20 C ! It seems like the WDT is ticking with much more short
period than expected - 4 ms instead 18 ms as per datasheets.
We spent two weeks in debugging exactly the tese two devices, but the
problem was that there was not quite repeatable pattern i.e. devices
sometimes worked with hours then the other day stopped work, this was
absolutely crazy as thousands of such devices were working without any
complain by our customers.
We were 1000% sure that this is some glitch in our code, then after
two weeks of banging our heads to the wall, we though that may be from
the PIC and read PIC16F876A errata sheets. There Microchips states
that for mask revision 02 some of the PIC16F876A may not execute code
right if clocked at more than 4Mhz!
They suggest the following test procedure if something goes wrong:
program 100 PICs and test them if they all behave the same the problem
is in your code, if some of them behave different th eproblem is in
the PICs ;) so we learned this the hard way.
These PICs were just from this early revision and out of 100 pcs lot
(we track we bought) only 2 were showing this.

Best regards
Tsvetan
---
PCB prototypes for $26 at http://run.to/pcb
(http://www.olimex.com/pcb)
Development boards for ARM, AVR, PIC, and MSP430 
(http://www.olimex.com/dev)

"Tsvetan Usunov" <tusunov@my-deja.com> wrote in message
news:dd52331e.0403052311.53ebf7a@posting.google.com...
>
> We use FT232 in one of our products, the issue we have with it is that
> out of 10 plugs in/out it fails operationg at least once.
> First we thought that it's something with the Windows USB drivers, but
> then we found that when it fails the FT232 chip have no oscillations
> i.e. it's pure hardware problem.
> The problem is not very anoying as in case of device fail you simple
> unplug and plug again and it works, but this left the impression in
> the customers that complete device is not very reliable.
> Did you experienced something like this?

I have never experienced this. We sold about 750 units of our product using
this chip and have never experienced this. I'd say it is a design/PCB layout
fault.

Meindert

> It depends on product volume and requirements.
> We used the DLP-USB245 module with great success.
> You can also buy the chips FT245BM.
> See http://www.dlpdesign.com/usb/usb245.html  module +-$25
> and http://www.ftdichip.com/FTProduct.htm  Chip +-$5
> The FT245 has an 8-bit paralel interface and the FT232 a serial interface.
> No USB programming required. Device drivers are free of charge.

We use FT232 in one of our products, the issue we have with it is that
out of 10 plugs in/out it fails operationg at least once.
First we thought that it's something with the Windows USB drivers, but
then we found that when it fails the FT232 chip have no oscillations
i.e. it's pure hardware problem.
The problem is not very anoying as in case of device fail you simple
unplug and plug again and it works, but this left the impression in
the customers that complete device is not very reliable.
Did you experienced something like this?

Best regards
Tsvetan
---
PCB prototypes for $26 at http://run.to/pcb
(http://www.olimex.com/pcb)
Development boards for ARM, AVR, PIC, and MSP430 
(http://www.olimex.com/dev)

"Steve Calfee" <stevecalfee@hotmail.com> wrote in message
news:dbnf409kjrf35kc6ih1ehv4dp6das5icga@4ax.com...
> On 15 Dec 2003 10:55:36 -0800, yqin_99@yahoo.com (yong) wrote:
>
> >What is the cheapest way to develop a USB device? The Cygnal F32x
> >seems good for its on chip USB controller. But it needs the Keil tools
> >which is expensive. Is there any USB tools(hardware/software) exsisted
> >which is under $500 for 8 bit microcontroller like 8051,PIC, or AVR?
> >For very low volume, I need low price development tools.
>
> The cheapest way is to buy a keyspan usb to serial device about $39.
> It contains a cypress ezusb chip, which gets its code downloaded when
> it is plugged in.
>
> see http://people.omnigroup.com/wiml/soft/pic/keyspan.html for a
> complete how-to. I have not tried it yet myself.
>
> HTH ~Steve
>

The Cygnal F32x device doesn't require the keil tools to use.  It is
basically an 8051 core so you can use any 8051 tool chain with.  The
examples that Cygnal provides are based on the keil toolset, but I
personally have programmed the part using other toolsets.

"Bob Stephens" <stephensyomamadigital@earthlink.net> wrote in message
news:1cshny7apnz4n.gio6bwzbbp9w.dlg@40tude.net...
>
> What OS's do they support?

Windows 98, ME, 2000, XP.
Max OS8/9, OSX
Linux (standard in every kernel after 2.2, I believe).

Meindert

On Fri, 5 Mar 2004 16:00:47 +0200, Gerhard v d Berg wrote:

> "Steve Calfee" <stevecalfee@hotmail.com> wrote in message
> news:dbnf409kjrf35kc6ih1ehv4dp6das5icga@4ax.com...
>> On 15 Dec 2003 10:55:36 -0800, yqin_99@yahoo.com (yong) wrote:
>>
>>>What is the cheapest way to develop a USB device? The Cygnal F32x
>>>seems good for its on chip USB controller. But it needs the Keil tools
>>>which is expensive. Is there any USB tools(hardware/software) exsisted
>>>which is under $500 for 8 bit microcontroller like 8051,PIC, or AVR?
>>>For very low volume, I need low price development tools.
>>
>> The cheapest way is to buy a keyspan usb to serial device about $39.
>> It contains a cypress ezusb chip, which gets its code downloaded when
>> it is plugged in.
>>
>> see http://people.omnigroup.com/wiml/soft/pic/keyspan.html for a
>> complete how-to. I have not tried it yet myself.
> 
> It depends on product volume and requirements.
> We used the DLP-USB245 module with great success.
> You can also buy the chips FT245BM.
> See http://www.dlpdesign.com/usb/usb245.html  module +-$25
> and http://www.ftdichip.com/FTProduct.htm  Chip +-$5
> The FT245 has an 8-bit paralel interface and the FT232 a serial interface.
> No USB programming required. Device drivers are free of charge.
> 
> Gerhard
> 
> 
> see

What OS's do they support?

Bob

"Steve Calfee" <stevecalfee@hotmail.com> wrote in message
news:dbnf409kjrf35kc6ih1ehv4dp6das5icga@4ax.com...
> On 15 Dec 2003 10:55:36 -0800, yqin_99@yahoo.com (yong) wrote:
>
> >What is the cheapest way to develop a USB device? The Cygnal F32x
> >seems good for its on chip USB controller. But it needs the Keil tools
> >which is expensive. Is there any USB tools(hardware/software) exsisted
> >which is under $500 for 8 bit microcontroller like 8051,PIC, or AVR?
> >For very low volume, I need low price development tools.
>
> The cheapest way is to buy a keyspan usb to serial device about $39.
> It contains a cypress ezusb chip, which gets its code downloaded when
> it is plugged in.
>
> see http://people.omnigroup.com/wiml/soft/pic/keyspan.html for a
> complete how-to. I have not tried it yet myself.

It depends on product volume and requirements.
We used the DLP-USB245 module with great success.
You can also buy the chips FT245BM.
See http://www.dlpdesign.com/usb/usb245.html  module +-$25
and http://www.ftdichip.com/FTProduct.htm  Chip +-$5
The FT245 has an 8-bit paralel interface and the FT232 a serial interface.
No USB programming required. Device drivers are free of charge.

Gerhard

see

On 15 Dec 2003 10:55:36 -0800, yqin_99@yahoo.com (yong) wrote:

>What is the cheapest way to develop a USB device? The Cygnal F32x
>seems good for its on chip USB controller. But it needs the Keil tools
>which is expensive. Is there any USB tools(hardware/software) exsisted
>which is under $500 for 8 bit microcontroller like 8051,PIC, or AVR?
>For very low volume, I need low price development tools.

The cheapest way is to buy a keyspan usb to serial device about $39.
It contains a cypress ezusb chip, which gets its code downloaded when
it is plugged in.

see http://people.omnigroup.com/wiml/soft/pic/keyspan.html for a
complete how-to. I have not tried it yet myself.

HTH ~Steve