https://wiki.iac.isu.edu/index.php?action=history&feed=atom&title=Spi_bus 2026-05-09T21:38:16Z Revision history for this page on the wiki MediaWiki 1.35.2 https://wiki.iac.isu.edu/index.php?title=Spi_bus&diff=24477&oldid=prev 2007-11-20T07:36:47Z

<p></p> <p><b>New page</b></p><div>==Use of SPI==<br /> Currently the main envisioned use of SPI is to program the AVR flash memory. Using the uisp program and robostix driver designed for interfacing Gumstix boards to Robostix boards, we should be able to program other AVR microcontrollers.<br /> <br /> ==SPI in our application==<br /> The SPI port utilizes the MISO, MOSI, [NSSP]FRAME, [NSSP]CLK, gnd, and Vcc. The signals are available on the console-st and breakout gumstix boards at a ~3V level with a 276ns risetime. When the signals are used internally with the Robostix they are level shifted using &quot;74LVC4245ATSSOP&quot; chips. The AVR specification defines a low signal as -0.5V to 0.3Vcc, and a high signal as 0.7Vcc to Vcc+0.5V. In our case level shifting to Vcc (5v probably) should be sufficient.</div>

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