AVR-Chat

Hi all,
   I'm new to this group, predominantly because I've always used PIC's
for control applications - but I've decided that it's time to give the
AVR a whirl; the feature list on the mega series AVR's is just too
good to pass up! :)

For my first design, I'm using a mega8 MCU for a closed loop
automotive control circuit, nothing terribly fancy, but I'm just
wondering about port allocations in terms of digital I/O's - I know
that on the older MCU's (PIC12Fxx, HC11 etc) there were significant
restrictions on what ports can be used for what function (i.e. PWM was
restricted to only a few pins, some ports were input or output only etc).

So, just before I go and get the PCB printed up, I was just hoping
that the knowledgable could cast their eye on my pin allocations that
I'm not doing anything impossible (or anything that's a particularly
bad idea! :).

I've read the data sheet cover to cover, and haven't come across
anything yet, although I'm still a bit vague as to which pins can
actually support PWM and whether different pins on different ports can
be allocated to different functions at the same time (e.g ADC Port -
can I do digital logic in, logic level out AND ADC conversion - all at
the same time?

PB0   - Out Piezo Buzzer Out (Direct Drive 20mA Max)
PB1,2 - Out PWM Drive 1,2 (to FET driver IC)
PD0,1 - In/Out RS232 Out via MAX232
PD2-7 - LCD Display Out
PB6   - Out SPI Device Slave Select
PB7   - In Keyboard (switches via 1N914's across PD2-7)
PC0   - 0-5v analogue in (for ADC use)
PC1-3 - +12v logic in (direct connect via 1k resistor)
PC4   - 0-5v analogue in (for ADC use)
PC5   - FET Drive (on/off) via FET Driver IC

MISO, SCK, MOSI - SPI Bus & ICP Header (Also LED via 500R resistor to
indicate SPI activity)

AREF,AVCC,VCC - Regulated +5v (no decoupling - direct connect)



Thanks in advance for your help.


Jon