PIC pwm circuit

[Frankie232]

Hello,

I am trying to power a load using a PWM signal generated by a PIC 18F452. The PIC will also compare the load current to a reference value and vary the pwm duty cycle as required. (Please see attached diagram).

How do I transform the block diagram into a circuit diagram? I would like the inputs to be on ports A and B, and the pwm output to be on port C but I don't know how to connect the pins.

Please help, I've never worked with a micro-controller before.

Many thanks.

 

[NickS]

What is your definition of transform? A circuit diagram is just like a block diagram with the exception that instead of blocks you actually piece together the specific parts. I will assume that you do know how to design the circuit(because that is really a different question entirely).

So where to start, How about the PIC. Have you chosen the exact device you want to use? If so then find its datasheet and read it. In it you will find a schematic picture of the part with listings of what function each pin does. Next you make a block that represents the PIC with numbered contacts. Next replace the block diagram block with your new part and then just take care to ensure that the wires are coming in and going out of the correct contacts.

Now just repeat for the rest of your circuits. You will either need to find a parts library or you will end up making your own.

You can find a list of circuit symbols here

 

[Frankie232]

Thanks. I was just confused about the PIC pins. I've figured it out.