The Idea part 2

16.1.2004 I have spent alot of time thinking about this project and not actually doing anything, so here we go. I have redesigned the hardware requirements abit, they are now:-

1) A small serial controlled VFD showing temperatures/Fan output
2) Several temperature sensors (CPU, Case,Inlet/Outlet Water Temperature,etc)
3) A serial connection to the PC, with a custom software reading/writing data to MBM
4) Atleast one fan controlled by a PWM signal to a LM317

The serial VFD would use 1 pin (TX)
Each temperature sensor uses 1 analog input
The serial port to the PC uses 2 pins(TX/RX) from the UART
Each fan uses 1 digital output.

There are problems that I must solve :-
1) The Mega8 only has 2 PWM outputs I think.
2) The Mega8 only has 1 UART so the serial output for the VFD needs to be created in software


Heres a design for the pwm output that I want to try today.

I'm not sure what values the resistor should have but I think that R1 should be 240ohm,R2 and R3 1K ohm. I'll need to play about until I find the best values :)