libftdi Archives

Subject: RE: strange chip select issue

From: bon@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
To: libftdi@xxxxxxxxxxxxxxxxxxxxxxx
Date: Tue, 10 Sep 2013 17:38:18 +0200
>>>>> "Chaves," == Chaves, Kevin <kevin.chaves@xxxxxxxxxxxxxxxx> writes:

    Chaves,> So I went and talked to some hardware people, and it was a very
    Chaves,> circular conversation. So she's going to look into the
    Chaves,> schematics in a bit, but she wouldn't believe me though. It
    Chaves,> works on windows it can't be a hardware issue. I kept trying to
    Chaves,> explain to her that identical code on linux will not toggle the
    Chaves,> chip select.  I'm not sure of the pins, but if using libMPPSSE
    Chaves,> I configured it using dbus3. I don't actually know what pin
    Chaves,> that is or how to explicitly configure the pin for CS on
    Chaves,> libftdi yet.

Did you check the EEPROM hint?

Another hint: Be sure you talk to the _right_ chip. Either have only one
FTDI chip on any USB connector of the PC or use some serial number to talk
to the exact chip.

Anything in the system log regarding USB communication or FTDI devices? 

Otherwise, write a short test in pure libftdi to toggle the pin. It's not
more than
- opening the _right_ chip
- switch to MPSSE Mode
- construct a MPSSE command to set the _right_ pin as output with 0 as
output
- construct a MPSSE command to set the _right_ pin as output with 1 as
output
- send both strings alternating
The examples should be a good staring point.

That excludes libMPSSE as possible error source.

    Chaves,> -----Original Message----- From:

B.t.w: Please quote less excessive. Excessive quoting spoils the archives.

-- 
Uwe Bonnes                bon@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------

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