AVR-Chat

You have /SS set as an input.  It either needs to be tied high, or, made an
output.  Read the data sheet w/regard to multi-master operation.


-----------
Larry Barello
www.barello.net


| -----Original Message-----
| From: AVR-Chat@yahoogroups.com [mailto:AVR-Chat@yahoogroups.com] On Behalf
| Of Robert Ussery
| 
| Hi, all...
| I'm having some trouble with an SPI interface on the Mega32, which I'm
| using to communicate with a TI TLV2543 ADC. I'm programming the micro in
| C using avr-gcc.
| 
| Here's my problem... using the SPI transmit code more or less straight
| from the Mega32 datasheet:
| 	SPDR = (channel<<4)|(ADCSetup);
| 	while(!(SPSR & (1<<SPIF)));
| my code keeps getting stuck in an infinite loop at that while()
| statement, but only on the 30th iteration or so (the micro loops through
| the ADC code indefinitely). The first 29ish times through the code,
| everything works perfectly. Am I missing something with how to handle
| the SPIF flag? I RTFM'd and all that, and it says that SPIF is set and
| reset automatically based on the SPI state and when SPDR is read.
| 
| I've included all of my code at the end of this email, but here are some
| of the more relevant parts:
| SPI setup:
| 	// Set MOSI and SCK output, all others input
| 	DDRB = (1<<PB5)|(1<<PB7);
| 	// Enable SPI, Master, set clock rate fck/128
| 	SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR1)|(1<<SPR0);
| 
| The ADC code is contained in the function ADCRead(), as shown in the
| code below.
| 
| Am I making some classic n00b mistake here? Any advice or pointers are
| welcome.