Generate PWM and control it with numbers between 0 and 9

[Jack Claudiu]

Hy to all, i have installed Proteus Isis and Mikro C pro
And i want to draw a scheme of a Microcontroller PIC which has serial port and PWM hardare and to satisfy the needs:
1) The circuit to be powered from 220V AC without transformer
2) To generate a pwm signal (Set in PWM hardware mode)
3)When we introduce a number in the serial port ( from 0 to 9) to set the PWM at a proportional value between the introduced number and the maximum value which the microcontroler accepts it
4) After setting the PWM value, to display on it`s serial port the value setted.

THe microcontroler runs conected to a crystal of 20Mhz ( if it hasn`t internal oscilator)
The serial port which is using is the hardware one and it`s baudrate must be 11520 (8N1)

Please Help me with some advices.
i`m stuck at point 3)
Thanx

 

[godfreyl]

Actually you're stuck at point one. How do you plan to isolate it from mains voltage without a transformer?

 

[Jack Claudiu]

Actually you're stuck at point one. How do you plan to isolate it from mains voltage without a transformer?

You`re right, thanx, i think i will use a diode bridge.
What do i need more to make the schematic ?

 

[godfreyl]

A normal supply would have a transformer, bridge rectifier and resevoir capacitor, followed by a voltage regulator circuit. The values depend on what voltage and current you need.