On 2014m07d17, at 23:33, Richard R. Pope wrote: Hello all, I hope someone can help me with this. I would like to output a=20 pulse for one second. This pulse has to be high for one second. It opens=20 a gate allowing the frequency to be counted to be applied to the counter=20 gates. Then the pulse is pulled low and the counting stops. I want to then output another high pulse of at least 20nS in=20 length. I want to be able to adjust the delay from the time that the=20 count pulse goes low and when this pulse is output. It would be nice to=20 have this pulse occur from say 1 second to never. I.E. the frequency=20 count can be updated from once a second to it can be held indefinitely. So for this I would think that a potentiometer being read by an ADC=20 could be used to control the update time for counting the frequency. A=20 low count would allow the updating to occur very often and a high=20 reading would result in no reset pulse being output. I have the picture=20 in my head but I just don't know how to translate that into software to=20 control the hardware. I was thinking that a pic16f628 would be the choice for doing this.=20 Can someone please spend some time with me and help me with this? I have=20 hit a wall. Thanks, rich! =97=20 #1 Pulse has to be high for one second plus/minus =85. how much precision = ? #2 At least 20nS in length =85.. is one hour okay ? 20nS to ????? #3 Most any micro-processor will do this=85.. the precision will depend on= the clock driving the micro-processor. #4 You can use a potentiometer into an ADC. I guess you would want to tra= nslate the incoming voltage into a logarithmic time function such as tim= e delay =3D n**(ADC-voltage * m). This could be done with a lookup table. = Instead of a potentiometer , you could have a pair of buttons ( up and dow= n ) . Or a digital rotary encoder. I guess the advantage of a pot is that= it will give you some kind of idea visually what the time delay is. If you are doing only one of these , I would recommend using a development = board to save time and effort. With more information, various PIClisters c= ould give you better advice. I may have a surplus board I could give you. Gus in Denver --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .