Controlling LEDs

I would like to build a unit that can control up to 20 LEDs.
Controlling time ON/OFF.
Would this be better controlled by using PIC. or can it be done any other way.

You apparently want to drive some LEDs using PWM. There are lots of ways to do that. For many applications a microcontroller is a good way to do that since it also has the capability to compute what the PWM duty cycle should be. Many micros have PWM hardware built in. PIC is Microchip's brand of microcontrollers, and many have native hardware PWM capability. For lower end PICs like the 16F and 18F families, PWM is one capability of what they call a CCP module (Compare, Capture and Pulse-width modulation).

Brian,

A microcontroller like a PIC could certainly be used for something like this. However, if you are trying to directly drive each LED individually from an equal number of GPIO pins and you have 20 of them you may exceed the total amount of current you can sink/source from the micro if too many of them are turned on at once. You may want to pulse groups of them out of phase with each other to reduce the maximum total current at any given point in time. You could also add an external LED driver IC or ICs controlled by your micro if it were still a problem.

If you have experience in programmable logic, something like a CPLD or FPGA may be a better choice since they generally have higher current handling capabilities from their I/O pins and you could probably directly drive dozens of LEDs as long as you heat sink the IC properly. It mostly depends on what sort of solution you are personally comfortable with trying to implement.

Thank you for your response.
Can I give you some more info regarding the unit I’m looking for. The finished unit will be put into a frame, like a picture frame. The LEDs. will then be displayed at various places within the frame. The frame can have vents to allow air flow. This will then be connected to a mains supply.
Once turned on the programmed LEDs will go through the timed flashing ON/OFF sequence, and then repeat .
I need something that I can programme because a second unit will go into another frame, this will have a different sequence to the first.
A long time ago I used to follow parts lists and circuit diagrams and assemble proto type boards for Electronic Engineers at a microwave communication company. I must say not knowing much about where or what they were going to be used for. Other work included assembling PCBs. and mechanical assembly.The parts used were nothing like the parts you mention.
I hope you can assist.

Thank you for your response.
Can I give you some more info regarding the unit I’m looking for. The finished unit will be put into a frame, like a picture frame. The LEDs. will then be displayed at various places within the frame. The frame can have vents to allow air flow. This will then be connected to a mains supply.
Once turned on the programmed LEDs will go through the timed flashing ON/OFF sequence, and then repeat .
I need something that I can programme because a second unit will go into another frame, this will have a different sequence to the first.
A long time ago I used to follow parts lists and circuit diagrams and assemble proto type boards for Electronic Engineers at a microwave communication company. I must say not knowing much about where or what they were going to be used for. Other work included assembling PCBs. and mechanical assembly.The parts used were nothing like the parts you mention.
I hope you can assist