For very low frequencies (I have used it for envelope generation) you can encode the duration of each step rather than the value at each sample. This gives much better data compression and low distortion. Thus you can use the EPROM to store the time between LSBs rather than the full sample value for each sample time, which results in megabytes of 0000s followed by terabytes of 0001s and petabytes of 0010s... lots of repetition. I would think a PIC12C509 fitted with an r2r ladder feeding an opamp-based lowpass filter would make an excellent 5-bit DAC for low frequencies. The sixth bit would be a serial control input. /\/\/\/*=Martin ----- Original Message ----- From: "Raymond Liu" To: Sent: Wednesday, February 20, 2002 9:23 AM Subject: Re: [EE]: Sine wave generation from simple components. > How about do it in digital way? An osillator, a ripple counter, an EPROM, a > R-2R network, and optionally a low-pass filter. Osillator can be as simple > as a cap and a resistor plus a schimitte trigger. Ripple counter can be > CD4040. Save the pre-calculated sine waveform in EPROM and use the counter > to read this waveform out. This may not be as simple as you expect but can > produce fairly stable sine signal. > > -Raymond > > -----Original Message----- > From: pic microcontroller discussion list > [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Nick Veys > Sent: February 20, 2002 2:34 AM > To: PICLIST@MITVMA.MIT.EDU > Subject: [EE]: Sine wave generation from simple components. > > > I've seen generating sine waves using PICs and other associated > "complex" hardware in the archives. And can find a /couple/ web sites > showing some oscillator and integrating amp sine generators but none > seem too complete or tested. > > I'm curious how I could go about generating a (roughly) 0-5 Vpp sine > wave, in the range of 1Hz or less... It doesn't have to be very > accurate, just simple, and generate a periodic wave. > > I'm looking for something made from (fairly) basic components (op amps > probably being the most complex), no 555 timers, etc, that's cheating! > > My engineering schooling is limited on the EE side (more digital) so I > can't seem to come up with something that works! :) > > Thanks! > > nick@veys.com | www.veys.com/nick > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu