AVR-Chat

David Kelly wrote:
> On Wed, Feb 08, 2006 at 10:49:08PM -0600, Chuck Hackett wrote:
> 
>>I guess I'd agree with Tom that assembler forces you to KNOW your
>>hardware environment better which is a good thing.  But, just because
>>one is using a higher level language like C doesn't relieve you from
>>having to know quite a lot about the hardware - assuming you're
>>interacting with the world outside the chip which is the point in
>>microcontrollers.
> 
> When I'm asked this question I recommend the AVR, avr-gcc, and the
> original K&R C book. Then add a reminder the K&R book "teaches" C by
> implementing common library utilities. That printf(), getchar(),
> putchar(), malloc(), etc, are not C, but nothing more than functions no
> different than any other one may write.
> 
> For embedded applications stay as far away as possible from the canned
> library functions. Especially printf() and malloc().
> 
> Also spend a lot of time looking at the generated assembly output. Is
> not so important as to be able to write assembly as it is to be able to
> read and understand what the compiler thought of your instructions. This
> way you know how expensive it is to attempt to abstract the UART via
> indirection in a structure. You know that 16 bit values require two
> accesses which an interrupt may jump in between. All those little things
> that differentiate code which happens to work vs. solid code which
> always works and is easy to maintain.
> 
> One parting note, use some sort of version system. CVS, Subversion,
> something, anything, from the start. Get used to frequently updating
> your repository with concise comments as to what you were doing or what
> motivated the changes. Comments in the code are important but the
> quality of comments in your commits are just as important.

It might seem very primitive, but i just copy "myprojectdir" to "myprojectdir-NNN"
onto a second HDD, incrementing the number each time. It acts as a short-term
backup, and you can easily browse old code. There's also live backup systems
for linux where snapshots are taken hourly or whatever time interval you want.