On Wed, Oct 8, 2008 at 5:18 PM, Albert Huitsing <albert@...> wrote:
> Jon Smirl schreef:
>> On Wed, Oct 8, 2008 at 4:23 PM, Albert Huitsing <albert@...>
>>> Hello all,
>>> On http://www.huitsing.com/irftdi you can find some additional info and
>>> a patchfile for building the software for my FTDI USB receiver.
>> Does the FTDI baud rate clock support 36, 38, 40 and 56Kb transmission?
> yep... should all work, and I expect even B&O 455Khz to work. The baudrate
> generator seems to be freely configurable, and the bitbang mode of the
> FTDI's completes it perfectly. In order to generate sample-base for 36 KHz,
> a baudrate of 4500 bps has to be selected (factor *125), so in order to
> generate 455Khz a baudrate of 455*125 = 56875bps should be selected (which
> is clearly below the supported standard 115200bps !)
> I've measured this with my scope and indeed I see +/- 455Khz bursts... but I
> don't have any B&O equipment to test ;-)
Insteon would be another interesting project based on the FTDI chip.
Insteon does home automation like x10, but Insteon actually works reliably.
It uses a 131.65Khz carrier with a 13.1165Khz data rate and BPSK encoding.
Schematics here towards the end...
I am waiting to get some embedded hardware back with an Insteon
circuit. We want to eliminate the PIC chip and decode/generate the
BPSK in software. I have serial lines available that do 25Mhz with
Is there enough power in the USB cable to make the 30V charge pump
needed for transmit?
I'd be working on the software right now if I had some hardware. I'm a
software developer, not a EE.
I can build from schematics, but I don't know enough to design things.
A FTDI based Insteon design would let me get started on the software.
Our project is at http://www.digispeaker.com. If you look back a page in the
blog there is a post with schematics for Insteon.
In this schematic the receive line is fed to an RC circuit and then
into the PIC chip. The PIC chip has a comparator on the input. Is that
circuit doing AGC?
>> This is another way to do a USB cable.
> which has the disadvantage of requiring 'burning' firmware in a CPU, the
> FTDI already has a kind of firmware inside which is very useable for my
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