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February 23, 2010
New River Community College
my dog, Ellie
News - Coexistence Agreement In …
about 5 years ago
This is great news indeed.
Now, could we concentrate on improving the SPI Shortcut?
With a little tweaking, this little gem just might go down in history as the next-best thing to sliced bread!
about 5 years ago
Further experiments that I have personally conducted with the SPI Shortcut have revealed the following:
Like clockwork, every eighth issuance of selection 1 under the ‘ACTIONS MENU:’, that is,
(1) Send command string
followed by a legitimate command string,
results in automatic hardware reset of the SPI Shortcut.
This causes the SPI Shortcut to reset to default settings for:
(1) clock polarity and phase, mode 1
(2) frequency, 500 KHz
(3) data order, MSB first
500 KHz and MSB first are ok, but, my application (AD9835 DDS control), requires clock polarity and phase, mode 3.
There are other issues with the SPI Shortcut, but they must remain broken until this arbitrary reset problem is resolved.
The SPI Shortcut holds great potential for inexpensive SPI-equipped modules to PC USB communications capability, but this potential will never be realized until this phantom reset issue is cured.
Please fix it, SparkFun!
I’m experiencing unexpected (and unwanted) resets of the ‘SPI Shortcut’, particularly while issuing commands from within the ‘Actions Menu:’.
In researching the problem, I found this:
“Note: Currently these boards may have a hardware bug (easily fixable). The reset pin of the FT232RL is tied to VBUS which confuses the FTDI chip, and might cause a malfunction. Our next batch of these will correct this issue by leaving the reset pin floating. For now, cutting the reset pin of the FTDI chip will resolve the problem; some boards will come with this fix already applied."
My ‘SPI Shortcut’ has the FT245RL chip instead of the above-mentioned FT232RL chip.
Any comments on this?
No public wish lists :(
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