Sorry. Reversed the prices. But, since OP appears to be a hobbyist, should deal in low volume prices (and possibly DIP packaging) On 15 December 2013 07:26, William "Chops" Westfield wrote= : > > how did you know that what I wanted was beyond the 555? > > The 555 has two timing resistors and a cap, and normally charges the cap > through both resistors, and discharges through one (or maybe the other wa= y > around; it's been a while.) For extremes of duty cycle, that isn't going > to work; to get long delays you need a big cap, but to get short pulses, > the resistors for that big cap become impossibly small. > > > >>> Cost of 555: 50c > >>> Cost of PIC: 20c > > Your vendor has excellent price on PICs (where? Which?) But is ripping > you off for 555's. > Digikey says about $0.38 for a PIC10F, and about $0.10 for a 555 (in q100= ) > As someone else pointed out; things get more complicated when both your > trigger signal and your output need to be 12V, and you want 100mA=85 > > (That said, it seems like by now there should be a "timer generator" > program where you feed in the details about the waveform you want, and it > spits out microcontroller code that implements that. No software design > required.) Especially if you're just talking about the sorts of waveform= s > a 555 can generate.) > > BillW > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 __________________________________________ David C Brown 43 Bings Road Whaley Bridge High Peak Phone: 01663 733236 Derbyshire eMail: dcb.home@gmail.com SK23 7ND web: www.bings-knowle.co.uk/dcb --=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 .