Matt I knocked out a board using the 74HCT08 logic IC and a LD1117V33 voltage regulator to guarantee a 3.3V supply voltage to the IC. I jumpered together the pair of logic input pins on each of the 4 IC gates and fed the PIC outputs CLK,SDO and SS to 3 of these IC input pairs. Fed the 3 IC outputs to the 28K256. The 28k256 SO line went straight to PIC SDI pin as before and as per tutorial schematic. I checked all of the IC output voltage levels using simple program to raise or lower PIC pins. These seemed ok dropping to 0v low or rising to 3.68V high.
Unfortunately when running sample program to read/write 28k256 via the 74HCT08, I get nothing but FF's. I have checked, checked and rechecked wiring but can't find anything wrong. I take it that it goes without saying that the 74HCT08 can switch at the clock speeds the SPI routines throw at it? I dropped the CLK speed down to the minimum but this showed no difference. Have you got any ideas where I might have slipped up? At least the resistor divider network worked up to a point!! Regards Dave On Sunday, 2 September 2012 02:51:10 UTC+1, mattschinkel wrote: > > Please try the 74HCT08. The resistor divider should work as well, but > 74HCT08 will give you better signals. > > -- You received this message because you are subscribed to the Google Groups "jallib" group. To view this discussion on the web visit https://groups.google.com/d/msg/jallib/-/ju2k8wmyxWsJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
