SPI Bus Mystery SOLVED
Posted on July 6, 2012 in Category: Blog - 0 Comments
The text The New Comet Plus Rocks! was stored in Flash and was repeatedly read and displayed.
So it turns out it was not the MISO line at all (see my post from June 21). It is the slave select that was not working. So what I thought to be was NO data coming back from the flash chip was correct - but for the wrong reason.
In my code, I am using the pre-declared variable A7 for the chip select on the flash. But when I tried using the same line to the blinking LED program, the LED did not light at all. So at least I now know the CS line is not activating. More to come after I figure out why...
Update: It appears that ports ADC6 and ADC7 are only analog inputs and are not dual-purpose digital I/O pins. That's gonna change a few things around in my design!