Originally Posted by MrDEB

one needs to learn how to walk before they can run.
Yes PICS will save alot of time and money IF one knows how to program AND has a pic programmer.
I myself would love to learn PIC programming BUT being on a fixed income and too busy to start from scratch and learn something new. Besides to use a pic one still needs to interface with the outside world using transistors or other old school hardware.
I have enough problems trying to get a stereo graphic equalizer with 2-10x10 leds displays designed and design the double sided boards to build the monster on.add a pocket TILT unit w/ 2- 10 led displays )a boy scout I have in my troop is building.I am scout master, Weblos den leader, electronics merit badge counselor etc))
the ammo counter that is in another post is one example.
the person has several errors in his/ her circuit involving basic digital logic and the use of transistors. YES a pic would work BUT he/ she still needs to have and learn pic programming. Its not something one learns overnight.
I don't mean to sound like a grumpy old man, I agree with you on the usage of a pic BUT??

Originally Posted by k7elp60

I think you mean increase the accuracy of the 556. I would change the values of your timing capacitors to a lower value and increase the timing value resistors. I have found by using good film capacitors and good quality trim pots the timing is reliable and repeatable. Sometimes high value of electrolytic capacitors have some leakage current the affects overall performance. Changing the 100uf capactor to a film may be a problem, but you might be able to use a 1uf and not have the timing resistor to large.
Another thing I have found is to put a electrolytic capacitor about 47uf very close to the 556 package. Connect this capacitor between Vcc and ground.