Re: ATmega169 Puzzle



larwe wrote:
Whenever I would try to lower the chip select lines of my devices the 169
would try it and then give up and reset itself.

Single-step; there is no reason why you shouldn't be able to use any
GPIO as your SPI _SS. Also check that your circuit is not wired in
some funky way whereby asserting _SS was shorting out the power
supply.


This may be the perfect time to leave the embedded/digital world for a minute, hang a scope on it and take a look.

--
Regards, Joerg

http://www.analogconsultants.com/
.



Relevant Pages

  • [patch 2.6.27-git] spi_gpio driver
    ... Generalize the old at91rm9200 "bootstrap" bitbanging SPI master driver ... On platforms that support inlined GPIO calls, ... config SPI_BITBANG ...
    (Linux-Kernel)
  • [PATCH v2] Add GPIO-based MMC/SD driver
    ... MMC/SD cards can be used on a GPIO based bus by bitbanging ... This driver provides a sysfs interface to dynamically create ... * Driver an MMC/SD card on a bitbanging GPIO SPI bus. ...
    (Linux-Kernel)
  • Re: [PATCH v2] Add GPIO-based MMC/SD driver
    ... * Driver an MMC/SD card on a bitbanging GPIO SPI bus. ... Driver "for" an MMC/SD card ... ...
    (Linux-Kernel)
  • Re: Phase frequency detector
    ... It doesn't seem possible that it can be caused by one of the latches ... This means both flops should have similar reset times. ... Recall this circuit has been used for decades and millions of parts ... So I think your code mislead you into believing that deadband was ...
    (sci.electronics.design)
  • Re: Initializing a Flip-Flop on Power-up
    ... It's pathetic what young engineers consider a POR these days. ... Got enough honey-do projects so I am not going to fix their design. ... If there is a regulator I take it off before that and after, then issue the reset before it is too close to dropout. ... But a hysteresis is a good thing though I have to confess that I sometimes forego it, but only if there is enough margin between threshold and the circuit actually conking out. ...
    (sci.electronics.design)